/*! image-blob-reduce 3.0.1 https://github.com/nodeca/image-blob-reduce @license MIT */
var assign$1 = function assign(to) {
  var from;

  for (var s = 1; s < arguments.length; s++) {
    from = Object(arguments[s]);

    for (var key in from) {
      if (Object.prototype.hasOwnProperty.call(from, key)) to[key] = from[key];
    }
  }

  return to;
};


function pick(from, props) {
  var to = {};

  props.forEach(function (key) {
    if (Object.prototype.hasOwnProperty.call(from, key)) to[key] = from[key];
  });

  return to;
}


function pick_pica_resize_options(from) {
  return pick(from, [
    'alpha',
    'unsharpAmount',
    'unsharpRadius',
    'unsharpThreshold',
    'cancelToken'
  ]);
}


var pick_1 = pick;
var pick_pica_resize_options_1 = pick_pica_resize_options;

var utils = {
	assign: assign$1,
	pick: pick_1,
	pick_pica_resize_options: pick_pica_resize_options_1
};

function createCommonjsModule(fn) {
  var module = { exports: {} };
	return fn(module, module.exports), module.exports;
}

function commonjsRequire (target) {
	throw new Error('Could not dynamically require "' + target + '". Please configure the dynamicRequireTargets option of @rollup/plugin-commonjs appropriately for this require call to behave properly.');
}

/*!

pica
https://github.com/nodeca/pica

*/

var pica = createCommonjsModule(function (module, exports) {
(function(f){{module.exports=f();}})(function(){return (function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof commonjsRequire&&commonjsRequire;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error("Cannot find module '"+i+"'");throw a.code="MODULE_NOT_FOUND",a}var p=n[i]={exports:{}};e[i][0].call(p.exports,function(r){var n=e[i][1][r];return o(n||r)},p,p.exports,r,e,n,t);}return n[i].exports}for(var u="function"==typeof commonjsRequire&&commonjsRequire,i=0;i<t.length;i++)o(t[i]);return o}return r})()({1:[function(_dereq_,module,exports){

var inherits = _dereq_('inherits');

var Multimath = _dereq_('multimath');

var mm_unsharp_mask = _dereq_('./mm_unsharp_mask');

var mm_resize = _dereq_('./mm_resize');

function MathLib(requested_features) {
  var __requested_features = requested_features || [];

  var features = {
    js: __requested_features.indexOf('js') >= 0,
    wasm: __requested_features.indexOf('wasm') >= 0
  };
  Multimath.call(this, features);
  this.features = {
    js: features.js,
    wasm: features.wasm && this.has_wasm()
  };
  this.use(mm_unsharp_mask);
  this.use(mm_resize);
}

inherits(MathLib, Multimath);

MathLib.prototype.resizeAndUnsharp = function resizeAndUnsharp(options, cache) {
  var result = this.resize(options, cache);

  if (options.unsharpAmount) {
    this.unsharp_mask(result, options.toWidth, options.toHeight, options.unsharpAmount, options.unsharpRadius, options.unsharpThreshold);
  }

  return result;
};

module.exports = MathLib;

},{"./mm_resize":4,"./mm_unsharp_mask":9,"inherits":19,"multimath":20}],2:[function(_dereq_,module,exports){
//var FIXED_FRAC_BITS = 14;

function clampTo8(i) {
  return i < 0 ? 0 : i > 255 ? 255 : i;
} // Convolve image in horizontal directions and transpose output. In theory,
// transpose allow:
//
// - use the same convolver for both passes (this fails due different
//   types of input array and temporary buffer)
// - making vertical pass by horisonltal lines inprove CPU cache use.
//
// But in real life this doesn't work :)
//


function convolveHorizontally(src, dest, srcW, srcH, destW, filters) {
  var r, g, b, a;
  var filterPtr, filterShift, filterSize;
  var srcPtr, srcY, destX, filterVal;
  var srcOffset = 0,
      destOffset = 0; // For each row

  for (srcY = 0; srcY < srcH; srcY++) {
    filterPtr = 0; // Apply precomputed filters to each destination row point

    for (destX = 0; destX < destW; destX++) {
      // Get the filter that determines the current output pixel.
      filterShift = filters[filterPtr++];
      filterSize = filters[filterPtr++];
      srcPtr = srcOffset + filterShift * 4 | 0;
      r = g = b = a = 0; // Apply the filter to the row to get the destination pixel r, g, b, a

      for (; filterSize > 0; filterSize--) {
        filterVal = filters[filterPtr++]; // Use reverse order to workaround deopts in old v8 (node v.10)
        // Big thanks to @mraleph (Vyacheslav Egorov) for the tip.

        a = a + filterVal * src[srcPtr + 3] | 0;
        b = b + filterVal * src[srcPtr + 2] | 0;
        g = g + filterVal * src[srcPtr + 1] | 0;
        r = r + filterVal * src[srcPtr] | 0;
        srcPtr = srcPtr + 4 | 0;
      } // Bring this value back in range. All of the filter scaling factors
      // are in fixed point with FIXED_FRAC_BITS bits of fractional part.
      //
      // (!) Add 1/2 of value before clamping to get proper rounding. In other
      // case brightness loss will be noticeable if you resize image with white
      // border and place it on white background.
      //


      dest[destOffset + 3] = clampTo8(a + (1 << 13) >> 14
      /*FIXED_FRAC_BITS*/
      );
      dest[destOffset + 2] = clampTo8(b + (1 << 13) >> 14
      /*FIXED_FRAC_BITS*/
      );
      dest[destOffset + 1] = clampTo8(g + (1 << 13) >> 14
      /*FIXED_FRAC_BITS*/
      );
      dest[destOffset] = clampTo8(r + (1 << 13) >> 14
      /*FIXED_FRAC_BITS*/
      );
      destOffset = destOffset + srcH * 4 | 0;
    }

    destOffset = (srcY + 1) * 4 | 0;
    srcOffset = (srcY + 1) * srcW * 4 | 0;
  }
} // Technically, convolvers are the same. But input array and temporary
// buffer can be of different type (especially, in old browsers). So,
// keep code in separate functions to avoid deoptimizations & speed loss.


function convolveVertically(src, dest, srcW, srcH, destW, filters) {
  var r, g, b, a;
  var filterPtr, filterShift, filterSize;
  var srcPtr, srcY, destX, filterVal;
  var srcOffset = 0,
      destOffset = 0; // For each row

  for (srcY = 0; srcY < srcH; srcY++) {
    filterPtr = 0; // Apply precomputed filters to each destination row point

    for (destX = 0; destX < destW; destX++) {
      // Get the filter that determines the current output pixel.
      filterShift = filters[filterPtr++];
      filterSize = filters[filterPtr++];
      srcPtr = srcOffset + filterShift * 4 | 0;
      r = g = b = a = 0; // Apply the filter to the row to get the destination pixel r, g, b, a

      for (; filterSize > 0; filterSize--) {
        filterVal = filters[filterPtr++]; // Use reverse order to workaround deopts in old v8 (node v.10)
        // Big thanks to @mraleph (Vyacheslav Egorov) for the tip.

        a = a + filterVal * src[srcPtr + 3] | 0;
        b = b + filterVal * src[srcPtr + 2] | 0;
        g = g + filterVal * src[srcPtr + 1] | 0;
        r = r + filterVal * src[srcPtr] | 0;
        srcPtr = srcPtr + 4 | 0;
      } // Bring this value back in range. All of the filter scaling factors
      // are in fixed point with FIXED_FRAC_BITS bits of fractional part.
      //
      // (!) Add 1/2 of value before clamping to get proper rounding. In other
      // case brightness loss will be noticeable if you resize image with white
      // border and place it on white background.
      //


      dest[destOffset + 3] = clampTo8(a + (1 << 13) >> 14
      /*FIXED_FRAC_BITS*/
      );
      dest[destOffset + 2] = clampTo8(b + (1 << 13) >> 14
      /*FIXED_FRAC_BITS*/
      );
      dest[destOffset + 1] = clampTo8(g + (1 << 13) >> 14
      /*FIXED_FRAC_BITS*/
      );
      dest[destOffset] = clampTo8(r + (1 << 13) >> 14
      /*FIXED_FRAC_BITS*/
      );
      destOffset = destOffset + srcH * 4 | 0;
    }

    destOffset = (srcY + 1) * 4 | 0;
    srcOffset = (srcY + 1) * srcW * 4 | 0;
  }
}

module.exports = {
  convolveHorizontally: convolveHorizontally,
  convolveVertically: convolveVertically
};

},{}],3:[function(_dereq_,module,exports){
/* eslint-disable max-len */

module.exports = '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';

},{}],4:[function(_dereq_,module,exports){

module.exports = {
  name: 'resize',
  fn: _dereq_('./resize'),
  wasm_fn: _dereq_('./resize_wasm'),
  wasm_src: _dereq_('./convolve_wasm_base64')
};

},{"./convolve_wasm_base64":3,"./resize":5,"./resize_wasm":8}],5:[function(_dereq_,module,exports){

var createFilters = _dereq_('./resize_filter_gen');

var convolveHorizontally = _dereq_('./convolve').convolveHorizontally;

var convolveVertically = _dereq_('./convolve').convolveVertically;

function resetAlpha(dst, width, height) {
  var ptr = 3,
      len = width * height * 4 | 0;

  while (ptr < len) {
    dst[ptr] = 0xFF;
    ptr = ptr + 4 | 0;
  }
}

module.exports = function resize(options) {
  var src = options.src;
  var srcW = options.width;
  var srcH = options.height;
  var destW = options.toWidth;
  var destH = options.toHeight;
  var scaleX = options.scaleX || options.toWidth / options.width;
  var scaleY = options.scaleY || options.toHeight / options.height;
  var offsetX = options.offsetX || 0;
  var offsetY = options.offsetY || 0;
  var dest = options.dest || new Uint8Array(destW * destH * 4);
  var quality = typeof options.quality === 'undefined' ? 3 : options.quality;
  var alpha = options.alpha || false;
  var filtersX = createFilters(quality, srcW, destW, scaleX, offsetX),
      filtersY = createFilters(quality, srcH, destH, scaleY, offsetY);
  var tmp = new Uint8Array(destW * srcH * 4); // To use single function we need src & tmp of the same type.
  // But src can be CanvasPixelArray, and tmp - Uint8Array. So, keep
  // vertical and horizontal passes separately to avoid deoptimization.

  convolveHorizontally(src, tmp, srcW, srcH, destW, filtersX);
  convolveVertically(tmp, dest, srcH, destW, destH, filtersY); // That's faster than doing checks in convolver.
  // !!! Note, canvas data is not premultipled. We don't need other
  // alpha corrections.

  if (!alpha) resetAlpha(dest, destW, destH);
  return dest;
};

},{"./convolve":2,"./resize_filter_gen":6}],6:[function(_dereq_,module,exports){

var FILTER_INFO = _dereq_('./resize_filter_info'); // Precision of fixed FP values


var FIXED_FRAC_BITS = 14;

function toFixedPoint(num) {
  return Math.round(num * ((1 << FIXED_FRAC_BITS) - 1));
}

module.exports = function resizeFilterGen(quality, srcSize, destSize, scale, offset) {
  var filterFunction = FILTER_INFO[quality].filter;
  var scaleInverted = 1.0 / scale;
  var scaleClamped = Math.min(1.0, scale); // For upscale
  // Filter window (averaging interval), scaled to src image

  var srcWindow = FILTER_INFO[quality].win / scaleClamped;
  var destPixel, srcPixel, srcFirst, srcLast, filterElementSize, floatFilter, fxpFilter, total, pxl, idx, floatVal, filterTotal, filterVal;
  var leftNotEmpty, rightNotEmpty, filterShift, filterSize;
  var maxFilterElementSize = Math.floor((srcWindow + 1) * 2);
  var packedFilter = new Int16Array((maxFilterElementSize + 2) * destSize);
  var packedFilterPtr = 0;
  var slowCopy = !packedFilter.subarray || !packedFilter.set; // For each destination pixel calculate source range and built filter values

  for (destPixel = 0; destPixel < destSize; destPixel++) {
    // Scaling should be done relative to central pixel point
    srcPixel = (destPixel + 0.5) * scaleInverted + offset;
    srcFirst = Math.max(0, Math.floor(srcPixel - srcWindow));
    srcLast = Math.min(srcSize - 1, Math.ceil(srcPixel + srcWindow));
    filterElementSize = srcLast - srcFirst + 1;
    floatFilter = new Float32Array(filterElementSize);
    fxpFilter = new Int16Array(filterElementSize);
    total = 0.0; // Fill filter values for calculated range

    for (pxl = srcFirst, idx = 0; pxl <= srcLast; pxl++, idx++) {
      floatVal = filterFunction((pxl + 0.5 - srcPixel) * scaleClamped);
      total += floatVal;
      floatFilter[idx] = floatVal;
    } // Normalize filter, convert to fixed point and accumulate conversion error


    filterTotal = 0;

    for (idx = 0; idx < floatFilter.length; idx++) {
      filterVal = floatFilter[idx] / total;
      filterTotal += filterVal;
      fxpFilter[idx] = toFixedPoint(filterVal);
    } // Compensate normalization error, to minimize brightness drift


    fxpFilter[destSize >> 1] += toFixedPoint(1.0 - filterTotal); //
    // Now pack filter to useable form
    //
    // 1. Trim heading and tailing zero values, and compensate shitf/length
    // 2. Put all to single array in this format:
    //
    //    [ pos shift, data length, value1, value2, value3, ... ]
    //

    leftNotEmpty = 0;

    while (leftNotEmpty < fxpFilter.length && fxpFilter[leftNotEmpty] === 0) {
      leftNotEmpty++;
    }

    if (leftNotEmpty < fxpFilter.length) {
      rightNotEmpty = fxpFilter.length - 1;

      while (rightNotEmpty > 0 && fxpFilter[rightNotEmpty] === 0) {
        rightNotEmpty--;
      }

      filterShift = srcFirst + leftNotEmpty;
      filterSize = rightNotEmpty - leftNotEmpty + 1;
      packedFilter[packedFilterPtr++] = filterShift; // shift

      packedFilter[packedFilterPtr++] = filterSize; // size

      if (!slowCopy) {
        packedFilter.set(fxpFilter.subarray(leftNotEmpty, rightNotEmpty + 1), packedFilterPtr);
        packedFilterPtr += filterSize;
      } else {
        // fallback for old IE < 11, without subarray/set methods
        for (idx = leftNotEmpty; idx <= rightNotEmpty; idx++) {
          packedFilter[packedFilterPtr++] = fxpFilter[idx];
        }
      }
    } else {
      // zero data, write header only
      packedFilter[packedFilterPtr++] = 0; // shift

      packedFilter[packedFilterPtr++] = 0; // size
    }
  }

  return packedFilter;
};

},{"./resize_filter_info":7}],7:[function(_dereq_,module,exports){

module.exports = [{
  // Nearest neibor (Box)
  win: 0.5,
  filter: function filter(x) {
    return x >= -0.5 && x < 0.5 ? 1.0 : 0.0;
  }
}, {
  // Hamming
  win: 1.0,
  filter: function filter(x) {
    if (x <= -1.0 || x >= 1.0) {
      return 0.0;
    }

    if (x > -1.19209290E-07 && x < 1.19209290E-07) {
      return 1.0;
    }

    var xpi = x * Math.PI;
    return Math.sin(xpi) / xpi * (0.54 + 0.46 * Math.cos(xpi / 1.0));
  }
}, {
  // Lanczos, win = 2
  win: 2.0,
  filter: function filter(x) {
    if (x <= -2.0 || x >= 2.0) {
      return 0.0;
    }

    if (x > -1.19209290E-07 && x < 1.19209290E-07) {
      return 1.0;
    }

    var xpi = x * Math.PI;
    return Math.sin(xpi) / xpi * Math.sin(xpi / 2.0) / (xpi / 2.0);
  }
}, {
  // Lanczos, win = 3
  win: 3.0,
  filter: function filter(x) {
    if (x <= -3.0 || x >= 3.0) {
      return 0.0;
    }

    if (x > -1.19209290E-07 && x < 1.19209290E-07) {
      return 1.0;
    }

    var xpi = x * Math.PI;
    return Math.sin(xpi) / xpi * Math.sin(xpi / 3.0) / (xpi / 3.0);
  }
}];

},{}],8:[function(_dereq_,module,exports){

var createFilters = _dereq_('./resize_filter_gen');

function resetAlpha(dst, width, height) {
  var ptr = 3,
      len = width * height * 4 | 0;

  while (ptr < len) {
    dst[ptr] = 0xFF;
    ptr = ptr + 4 | 0;
  }
}

function asUint8Array(src) {
  return new Uint8Array(src.buffer, 0, src.byteLength);
}

var IS_LE = true; // should not crash everything on module load in old browsers

try {
  IS_LE = new Uint32Array(new Uint8Array([1, 0, 0, 0]).buffer)[0] === 1;
} catch (__) {}

function copyInt16asLE(src, target, target_offset) {
  if (IS_LE) {
    target.set(asUint8Array(src), target_offset);
    return;
  }

  for (var ptr = target_offset, i = 0; i < src.length; i++) {
    var data = src[i];
    target[ptr++] = data & 0xFF;
    target[ptr++] = data >> 8 & 0xFF;
  }
}

module.exports = function resize_wasm(options) {
  var src = options.src;
  var srcW = options.width;
  var srcH = options.height;
  var destW = options.toWidth;
  var destH = options.toHeight;
  var scaleX = options.scaleX || options.toWidth / options.width;
  var scaleY = options.scaleY || options.toHeight / options.height;
  var offsetX = options.offsetX || 0.0;
  var offsetY = options.offsetY || 0.0;
  var dest = options.dest || new Uint8Array(destW * destH * 4);
  var quality = typeof options.quality === 'undefined' ? 3 : options.quality;
  var alpha = options.alpha || false;
  var filtersX = createFilters(quality, srcW, destW, scaleX, offsetX),
      filtersY = createFilters(quality, srcH, destH, scaleY, offsetY); // destination is 0 too.

  var src_offset = 0; // buffer between convolve passes

  var tmp_offset = this.__align(src_offset + Math.max(src.byteLength, dest.byteLength));

  var filtersX_offset = this.__align(tmp_offset + srcH * destW * 4);

  var filtersY_offset = this.__align(filtersX_offset + filtersX.byteLength);

  var alloc_bytes = filtersY_offset + filtersY.byteLength;

  var instance = this.__instance('resize', alloc_bytes); //
  // Fill memory block with data to process
  //


  var mem = new Uint8Array(this.__memory.buffer);
  var mem32 = new Uint32Array(this.__memory.buffer); // 32-bit copy is much faster in chrome

  var src32 = new Uint32Array(src.buffer);
  mem32.set(src32); // We should guarantee LE bytes order. Filters are not big, so
  // speed difference is not significant vs direct .set()

  copyInt16asLE(filtersX, mem, filtersX_offset);
  copyInt16asLE(filtersY, mem, filtersY_offset); //
  // Now call webassembly method
  // emsdk does method names with '_'

  var fn = instance.exports.convolveHV || instance.exports._convolveHV;
  fn(filtersX_offset, filtersY_offset, tmp_offset, srcW, srcH, destW, destH); //
  // Copy data back to typed array
  //
  // 32-bit copy is much faster in chrome

  var dest32 = new Uint32Array(dest.buffer);
  dest32.set(new Uint32Array(this.__memory.buffer, 0, destH * destW)); // That's faster than doing checks in convolver.
  // !!! Note, canvas data is not premultipled. We don't need other
  // alpha corrections.

  if (!alpha) resetAlpha(dest, destW, destH);
  return dest;
};

},{"./resize_filter_gen":6}],9:[function(_dereq_,module,exports){

module.exports = {
  name: 'unsharp_mask',
  fn: _dereq_('./unsharp_mask'),
  wasm_fn: _dereq_('./unsharp_mask_wasm'),
  wasm_src: _dereq_('./unsharp_mask_wasm_base64')
};

},{"./unsharp_mask":10,"./unsharp_mask_wasm":11,"./unsharp_mask_wasm_base64":12}],10:[function(_dereq_,module,exports){

var glur_mono16 = _dereq_('glur/mono16');

function hsv_v16(img, width, height) {
  var size = width * height;
  var out = new Uint16Array(size);
  var r, g, b, max;

  for (var i = 0; i < size; i++) {
    r = img[4 * i];
    g = img[4 * i + 1];
    b = img[4 * i + 2];
    max = r >= g && r >= b ? r : g >= b && g >= r ? g : b;
    out[i] = max << 8;
  }

  return out;
}

module.exports = function unsharp(img, width, height, amount, radius, threshold) {
  var v1, v2, vmul;
  var diff, iTimes4;

  if (amount === 0 || radius < 0.5) {
    return;
  }

  if (radius > 2.0) {
    radius = 2.0;
  }

  var brightness = hsv_v16(img, width, height);
  var blured = new Uint16Array(brightness); // copy, because blur modify src

  glur_mono16(blured, width, height, radius);
  var amountFp = amount / 100 * 0x1000 + 0.5 | 0;
  var thresholdFp = threshold << 8;
  var size = width * height;
  /* eslint-disable indent */

  for (var i = 0; i < size; i++) {
    v1 = brightness[i];
    diff = v1 - blured[i];

    if (Math.abs(diff) >= thresholdFp) {
      // add unsharp mask to the brightness channel
      v2 = v1 + (amountFp * diff + 0x800 >> 12); // Both v1 and v2 are within [0.0 .. 255.0] (0000-FF00) range, never going into
      // [255.003 .. 255.996] (FF01-FFFF). This allows to round this value as (x+.5)|0
      // later without overflowing.

      v2 = v2 > 0xff00 ? 0xff00 : v2;
      v2 = v2 < 0x0000 ? 0x0000 : v2; // Avoid division by 0. V=0 means rgb(0,0,0), unsharp with unsharpAmount>0 cannot
      // change this value (because diff between colors gets inflated), so no need to verify correctness.

      v1 = v1 !== 0 ? v1 : 1; // Multiplying V in HSV model by a constant is equivalent to multiplying each component
      // in RGB by the same constant (same for HSL), see also:
      // https://beesbuzz.biz/code/16-hsv-color-transforms

      vmul = (v2 << 12) / v1 | 0; // Result will be in [0..255] range because:
      //  - all numbers are positive
      //  - r,g,b <= (v1/256)
      //  - r,g,b,(v1/256),(v2/256) <= 255
      // So highest this number can get is X*255/X+0.5=255.5 which is < 256 and rounds down.

      iTimes4 = i * 4;
      img[iTimes4] = img[iTimes4] * vmul + 0x800 >> 12; // R

      img[iTimes4 + 1] = img[iTimes4 + 1] * vmul + 0x800 >> 12; // G

      img[iTimes4 + 2] = img[iTimes4 + 2] * vmul + 0x800 >> 12; // B
    }
  }
};

},{"glur/mono16":18}],11:[function(_dereq_,module,exports){

module.exports = function unsharp(img, width, height, amount, radius, threshold) {
  if (amount === 0 || radius < 0.5) {
    return;
  }

  if (radius > 2.0) {
    radius = 2.0;
  }

  var pixels = width * height;
  var img_bytes_cnt = pixels * 4;
  var hsv_bytes_cnt = pixels * 2;
  var blur_bytes_cnt = pixels * 2;
  var blur_line_byte_cnt = Math.max(width, height) * 4; // float32 array

  var blur_coeffs_byte_cnt = 8 * 4; // float32 array

  var img_offset = 0;
  var hsv_offset = img_bytes_cnt;
  var blur_offset = hsv_offset + hsv_bytes_cnt;
  var blur_tmp_offset = blur_offset + blur_bytes_cnt;
  var blur_line_offset = blur_tmp_offset + blur_bytes_cnt;
  var blur_coeffs_offset = blur_line_offset + blur_line_byte_cnt;

  var instance = this.__instance('unsharp_mask', img_bytes_cnt + hsv_bytes_cnt + blur_bytes_cnt * 2 + blur_line_byte_cnt + blur_coeffs_byte_cnt, {
    exp: Math.exp
  }); // 32-bit copy is much faster in chrome


  var img32 = new Uint32Array(img.buffer);
  var mem32 = new Uint32Array(this.__memory.buffer);
  mem32.set(img32); // HSL

  var fn = instance.exports.hsv_v16 || instance.exports._hsv_v16;
  fn(img_offset, hsv_offset, width, height); // BLUR

  fn = instance.exports.blurMono16 || instance.exports._blurMono16;
  fn(hsv_offset, blur_offset, blur_tmp_offset, blur_line_offset, blur_coeffs_offset, width, height, radius); // UNSHARP

  fn = instance.exports.unsharp || instance.exports._unsharp;
  fn(img_offset, img_offset, hsv_offset, blur_offset, width, height, amount, threshold); // 32-bit copy is much faster in chrome

  img32.set(new Uint32Array(this.__memory.buffer, 0, pixels));
};

},{}],12:[function(_dereq_,module,exports){
/* eslint-disable max-len */

module.exports = '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';

},{}],13:[function(_dereq_,module,exports){

var GC_INTERVAL = 100;

function Pool(create, idle) {
  this.create = create;
  this.available = [];
  this.acquired = {};
  this.lastId = 1;
  this.timeoutId = 0;
  this.idle = idle || 2000;
}

Pool.prototype.acquire = function () {
  var _this = this;

  var resource;

  if (this.available.length !== 0) {
    resource = this.available.pop();
  } else {
    resource = this.create();
    resource.id = this.lastId++;

    resource.release = function () {
      return _this.release(resource);
    };
  }

  this.acquired[resource.id] = resource;
  return resource;
};

Pool.prototype.release = function (resource) {
  var _this2 = this;

  delete this.acquired[resource.id];
  resource.lastUsed = Date.now();
  this.available.push(resource);

  if (this.timeoutId === 0) {
    this.timeoutId = setTimeout(function () {
      return _this2.gc();
    }, GC_INTERVAL);
  }
};

Pool.prototype.gc = function () {
  var _this3 = this;

  var now = Date.now();
  this.available = this.available.filter(function (resource) {
    if (now - resource.lastUsed > _this3.idle) {
      resource.destroy();
      return false;
    }

    return true;
  });

  if (this.available.length !== 0) {
    this.timeoutId = setTimeout(function () {
      return _this3.gc();
    }, GC_INTERVAL);
  } else {
    this.timeoutId = 0;
  }
};

module.exports = Pool;

},{}],14:[function(_dereq_,module,exports){
// min size = 1 can consume large amount of memory

var MIN_INNER_TILE_SIZE = 2;

module.exports = function createStages(fromWidth, fromHeight, toWidth, toHeight, srcTileSize, destTileBorder) {
  var scaleX = toWidth / fromWidth;
  var scaleY = toHeight / fromHeight; // derived from createRegions equation:
  // innerTileWidth = pixelFloor(srcTileSize * scaleX) - 2 * destTileBorder;

  var minScale = (2 * destTileBorder + MIN_INNER_TILE_SIZE + 1) / srcTileSize; // refuse to scale image multiple times by less than twice each time,
  // it could only happen because of invalid options

  if (minScale > 0.5) return [[toWidth, toHeight]];
  var stageCount = Math.ceil(Math.log(Math.min(scaleX, scaleY)) / Math.log(minScale)); // no additional resizes are necessary,
  // stageCount can be zero or be negative when enlarging the image

  if (stageCount <= 1) return [[toWidth, toHeight]];
  var result = [];

  for (var i = 0; i < stageCount; i++) {
    var width = Math.round(Math.pow(Math.pow(fromWidth, stageCount - i - 1) * Math.pow(toWidth, i + 1), 1 / stageCount));
    var height = Math.round(Math.pow(Math.pow(fromHeight, stageCount - i - 1) * Math.pow(toHeight, i + 1), 1 / stageCount));
    result.push([width, height]);
  }

  return result;
};

},{}],15:[function(_dereq_,module,exports){
/*
 * pixelFloor and pixelCeil are modified versions of Math.floor and Math.ceil
 * functions which take into account floating point arithmetic errors.
 * Those errors can cause undesired increments/decrements of sizes and offsets:
 * Math.ceil(36 / (36 / 500)) = 501
 * pixelCeil(36 / (36 / 500)) = 500
 */

var PIXEL_EPSILON = 1e-5;

function pixelFloor(x) {
  var nearest = Math.round(x);

  if (Math.abs(x - nearest) < PIXEL_EPSILON) {
    return nearest;
  }

  return Math.floor(x);
}

function pixelCeil(x) {
  var nearest = Math.round(x);

  if (Math.abs(x - nearest) < PIXEL_EPSILON) {
    return nearest;
  }

  return Math.ceil(x);
}

module.exports = function createRegions(options) {
  var scaleX = options.toWidth / options.width;
  var scaleY = options.toHeight / options.height;
  var innerTileWidth = pixelFloor(options.srcTileSize * scaleX) - 2 * options.destTileBorder;
  var innerTileHeight = pixelFloor(options.srcTileSize * scaleY) - 2 * options.destTileBorder; // prevent infinite loop, this should never happen

  if (innerTileWidth < 1 || innerTileHeight < 1) {
    throw new Error('Internal error in pica: target tile width/height is too small.');
  }

  var x, y;
  var innerX, innerY, toTileWidth, toTileHeight;
  var tiles = [];
  var tile; // we go top-to-down instead of left-to-right to make image displayed from top to
  // doesn in the browser

  for (innerY = 0; innerY < options.toHeight; innerY += innerTileHeight) {
    for (innerX = 0; innerX < options.toWidth; innerX += innerTileWidth) {
      x = innerX - options.destTileBorder;

      if (x < 0) {
        x = 0;
      }

      toTileWidth = innerX + innerTileWidth + options.destTileBorder - x;

      if (x + toTileWidth >= options.toWidth) {
        toTileWidth = options.toWidth - x;
      }

      y = innerY - options.destTileBorder;

      if (y < 0) {
        y = 0;
      }

      toTileHeight = innerY + innerTileHeight + options.destTileBorder - y;

      if (y + toTileHeight >= options.toHeight) {
        toTileHeight = options.toHeight - y;
      }

      tile = {
        toX: x,
        toY: y,
        toWidth: toTileWidth,
        toHeight: toTileHeight,
        toInnerX: innerX,
        toInnerY: innerY,
        toInnerWidth: innerTileWidth,
        toInnerHeight: innerTileHeight,
        offsetX: x / scaleX - pixelFloor(x / scaleX),
        offsetY: y / scaleY - pixelFloor(y / scaleY),
        scaleX: scaleX,
        scaleY: scaleY,
        x: pixelFloor(x / scaleX),
        y: pixelFloor(y / scaleY),
        width: pixelCeil(toTileWidth / scaleX),
        height: pixelCeil(toTileHeight / scaleY)
      };
      tiles.push(tile);
    }
  }

  return tiles;
};

},{}],16:[function(_dereq_,module,exports){

function objClass(obj) {
  return Object.prototype.toString.call(obj);
}

module.exports.isCanvas = function isCanvas(element) {
  var cname = objClass(element);
  return cname === '[object HTMLCanvasElement]'
  /* browser */
  || cname === '[object OffscreenCanvas]' || cname === '[object Canvas]'
  /* node-canvas */
  ;
};

module.exports.isImage = function isImage(element) {
  return objClass(element) === '[object HTMLImageElement]';
};

module.exports.isImageBitmap = function isImageBitmap(element) {
  return objClass(element) === '[object ImageBitmap]';
};

module.exports.limiter = function limiter(concurrency) {
  var active = 0,
      queue = [];

  function roll() {
    if (active < concurrency && queue.length) {
      active++;
      queue.shift()();
    }
  }

  return function limit(fn) {
    return new Promise(function (resolve, reject) {
      queue.push(function () {
        fn().then(function (result) {
          resolve(result);
          active--;
          roll();
        }, function (err) {
          reject(err);
          active--;
          roll();
        });
      });
      roll();
    });
  };
};

module.exports.cib_quality_name = function cib_quality_name(num) {
  switch (num) {
    case 0:
      return 'pixelated';

    case 1:
      return 'low';

    case 2:
      return 'medium';
  }

  return 'high';
};

module.exports.cib_support = function cib_support(createCanvas) {
  return Promise.resolve().then(function () {
    if (typeof createImageBitmap === 'undefined') {
      return false;
    }

    var c = createCanvas(100, 100);
    return createImageBitmap(c, 0, 0, 100, 100, {
      resizeWidth: 10,
      resizeHeight: 10,
      resizeQuality: 'high'
    }).then(function (bitmap) {
      var status = bitmap.width === 10; // Branch below is filtered on upper level. We do not call resize
      // detection for basic ImageBitmap.
      //
      // https://developer.mozilla.org/en-US/docs/Web/API/ImageBitmap
      // old Crome 51 has ImageBitmap without .close(). Then this code
      // will throw and return 'false' as expected.
      //

      bitmap.close();
      c = null;
      return status;
    });
  })["catch"](function () {
    return false;
  });
};

module.exports.worker_offscreen_canvas_support = function worker_offscreen_canvas_support() {
  return new Promise(function (resolve, reject) {
    if (typeof OffscreenCanvas === 'undefined') {
      // if OffscreenCanvas is present, we assume browser supports Worker and built-in Promise as well
      resolve(false);
      return;
    }

    function workerPayload(self) {
      if (typeof createImageBitmap === 'undefined') {
        self.postMessage(false);
        return;
      }

      Promise.resolve().then(function () {
        var canvas = new OffscreenCanvas(10, 10); // test that 2d context can be used in worker

        var ctx = canvas.getContext('2d');
        ctx.rect(0, 0, 1, 1); // test that cib can be used to return image bitmap from worker

        return createImageBitmap(canvas, 0, 0, 1, 1);
      }).then(function () {
        return self.postMessage(true);
      }, function () {
        return self.postMessage(false);
      });
    }

    var code = btoa("(".concat(workerPayload.toString(), ")(self);"));
    var w = new Worker("data:text/javascript;base64,".concat(code));

    w.onmessage = function (ev) {
      return resolve(ev.data);
    };

    w.onerror = reject;
  }).then(function (result) {
    return result;
  }, function () {
    return false;
  });
}; // Check if canvas.getContext('2d').getImageData can be used,
// FireFox randomizes the output of that function in `privacy.resistFingerprinting` mode


module.exports.can_use_canvas = function can_use_canvas(createCanvas) {
  var usable = false;

  try {
    var canvas = createCanvas(2, 1);
    var ctx = canvas.getContext('2d');
    var d = ctx.createImageData(2, 1);
    d.data[0] = 12;
    d.data[1] = 23;
    d.data[2] = 34;
    d.data[3] = 255;
    d.data[4] = 45;
    d.data[5] = 56;
    d.data[6] = 67;
    d.data[7] = 255;
    ctx.putImageData(d, 0, 0);
    d = null;
    d = ctx.getImageData(0, 0, 2, 1);

    if (d.data[0] === 12 && d.data[1] === 23 && d.data[2] === 34 && d.data[3] === 255 && d.data[4] === 45 && d.data[5] === 56 && d.data[6] === 67 && d.data[7] === 255) {
      usable = true;
    }
  } catch (err) {}

  return usable;
}; // Check if createImageBitmap(img, sx, sy, sw, sh) signature works correctly
// with JPEG images oriented with Exif;
// https://bugs.chromium.org/p/chromium/issues/detail?id=1220671
// TODO: remove after it's fixed in chrome for at least 2 releases


module.exports.cib_can_use_region = function cib_can_use_region() {
  return new Promise(function (resolve) {
    if (typeof createImageBitmap === 'undefined') {
      resolve(false);
      return;
    }

    var image = new Image();
    image.src = 'data:image/jpeg;base64,' + '/9j/4QBiRXhpZgAATU0AKgAAAAgABQESAAMAAAABAAYAAAEaAAUAAAABAAAASgEbAAUAA' + 'AABAAAAUgEoAAMAAAABAAIAAAITAAMAAAABAAEAAAAAAAAAAABIAAAAAQAAAEgAAAAB/9' + 'sAQwAEAwMEAwMEBAMEBQQEBQYKBwYGBgYNCQoICg8NEBAPDQ8OERMYFBESFxIODxUcFRc' + 'ZGRsbGxAUHR8dGh8YGhsa/9sAQwEEBQUGBQYMBwcMGhEPERoaGhoaGhoaGhoaGhoaGhoa' + 'GhoaGhoaGhoaGhoaGhoaGhoaGhoaGhoaGhoaGhoaGhoa/8IAEQgAAQACAwERAAIRAQMRA' + 'f/EABQAAQAAAAAAAAAAAAAAAAAAAAf/xAAUAQEAAAAAAAAAAAAAAAAAAAAA/9oADAMBAA' + 'IQAxAAAAF/P//EABQQAQAAAAAAAAAAAAAAAAAAAAD/2gAIAQEAAQUCf//EABQRAQAAAAA' + 'AAAAAAAAAAAAAAAD/2gAIAQMBAT8Bf//EABQRAQAAAAAAAAAAAAAAAAAAAAD/2gAIAQIB' + 'AT8Bf//EABQQAQAAAAAAAAAAAAAAAAAAAAD/2gAIAQEABj8Cf//EABQQAQAAAAAAAAAAA' + 'AAAAAAAAAD/2gAIAQEAAT8hf//aAAwDAQACAAMAAAAQH//EABQRAQAAAAAAAAAAAAAAAA' + 'AAAAD/2gAIAQMBAT8Qf//EABQRAQAAAAAAAAAAAAAAAAAAAAD/2gAIAQIBAT8Qf//EABQ' + 'QAQAAAAAAAAAAAAAAAAAAAAD/2gAIAQEAAT8Qf//Z';

    image.onload = function () {
      createImageBitmap(image, 0, 0, image.width, image.height).then(function (bitmap) {
        if (bitmap.width === image.width && bitmap.height === image.height) {
          resolve(true);
        } else {
          resolve(false);
        }
      }, function () {
        return resolve(false);
      });
    };

    image.onerror = function () {
      return resolve(false);
    };
  });
};

},{}],17:[function(_dereq_,module,exports){

module.exports = function () {
  var MathLib = _dereq_('./mathlib');

  var mathLib;
  /* eslint-disable no-undef */

  onmessage = function onmessage(ev) {
    var tileOpts = ev.data.opts;
    var returnBitmap = false;

    if (!tileOpts.src && tileOpts.srcBitmap) {
      var canvas = new OffscreenCanvas(tileOpts.width, tileOpts.height);
      var ctx = canvas.getContext('2d', {
        alpha: Boolean(tileOpts.alpha)
      });
      ctx.drawImage(tileOpts.srcBitmap, 0, 0);
      tileOpts.src = ctx.getImageData(0, 0, tileOpts.width, tileOpts.height).data;
      canvas.width = canvas.height = 0;
      canvas = null;
      tileOpts.srcBitmap.close();
      tileOpts.srcBitmap = null;
      returnBitmap = true;
    }

    if (!mathLib) mathLib = new MathLib(ev.data.features); // Use multimath's sync auto-init. Avoid Promise use in old browsers,
    // because polyfills are not propagated to webworker.

    var data = mathLib.resizeAndUnsharp(tileOpts);

    if (returnBitmap) {
      var toImageData = new ImageData(new Uint8ClampedArray(data), tileOpts.toWidth, tileOpts.toHeight);

      var _canvas = new OffscreenCanvas(tileOpts.toWidth, tileOpts.toHeight);

      var _ctx = _canvas.getContext('2d', {
        alpha: Boolean(tileOpts.alpha)
      });

      _ctx.putImageData(toImageData, 0, 0);

      createImageBitmap(_canvas).then(function (bitmap) {
        postMessage({
          bitmap: bitmap
        }, [bitmap]);
      });
    } else {
      postMessage({
        data: data
      }, [data.buffer]);
    }
  };
};

},{"./mathlib":1}],18:[function(_dereq_,module,exports){
// Calculate Gaussian blur of an image using IIR filter
// The method is taken from Intel's white paper and code example attached to it:
// https://software.intel.com/en-us/articles/iir-gaussian-blur-filter
// -implementation-using-intel-advanced-vector-extensions

var a0, a1, a2, a3, b1, b2, left_corner, right_corner;

function gaussCoef(sigma) {
  if (sigma < 0.5) {
    sigma = 0.5;
  }

  var a = Math.exp(0.726 * 0.726) / sigma,
      g1 = Math.exp(-a),
      g2 = Math.exp(-2 * a),
      k = (1 - g1) * (1 - g1) / (1 + 2 * a * g1 - g2);

  a0 = k;
  a1 = k * (a - 1) * g1;
  a2 = k * (a + 1) * g1;
  a3 = -k * g2;
  b1 = 2 * g1;
  b2 = -g2;
  left_corner = (a0 + a1) / (1 - b1 - b2);
  right_corner = (a2 + a3) / (1 - b1 - b2);

  // Attempt to force type to FP32.
  return new Float32Array([ a0, a1, a2, a3, b1, b2, left_corner, right_corner ]);
}

function convolveMono16(src, out, line, coeff, width, height) {
  // takes src image and writes the blurred and transposed result into out

  var prev_src, curr_src, curr_out, prev_out, prev_prev_out;
  var src_index, out_index, line_index;
  var i, j;
  var coeff_a0, coeff_a1, coeff_b1, coeff_b2;

  for (i = 0; i < height; i++) {
    src_index = i * width;
    out_index = i;
    line_index = 0;

    // left to right
    prev_src = src[src_index];
    prev_prev_out = prev_src * coeff[6];
    prev_out = prev_prev_out;

    coeff_a0 = coeff[0];
    coeff_a1 = coeff[1];
    coeff_b1 = coeff[4];
    coeff_b2 = coeff[5];

    for (j = 0; j < width; j++) {
      curr_src = src[src_index];

      curr_out = curr_src * coeff_a0 +
                 prev_src * coeff_a1 +
                 prev_out * coeff_b1 +
                 prev_prev_out * coeff_b2;

      prev_prev_out = prev_out;
      prev_out = curr_out;
      prev_src = curr_src;

      line[line_index] = prev_out;
      line_index++;
      src_index++;
    }

    src_index--;
    line_index--;
    out_index += height * (width - 1);

    // right to left
    prev_src = src[src_index];
    prev_prev_out = prev_src * coeff[7];
    prev_out = prev_prev_out;
    curr_src = prev_src;

    coeff_a0 = coeff[2];
    coeff_a1 = coeff[3];

    for (j = width - 1; j >= 0; j--) {
      curr_out = curr_src * coeff_a0 +
                 prev_src * coeff_a1 +
                 prev_out * coeff_b1 +
                 prev_prev_out * coeff_b2;

      prev_prev_out = prev_out;
      prev_out = curr_out;

      prev_src = curr_src;
      curr_src = src[src_index];

      out[out_index] = line[line_index] + prev_out;

      src_index--;
      line_index--;
      out_index -= height;
    }
  }
}


function blurMono16(src, width, height, radius) {
  // Quick exit on zero radius
  if (!radius) { return; }

  var out      = new Uint16Array(src.length),
      tmp_line = new Float32Array(Math.max(width, height));

  var coeff = gaussCoef(radius);

  convolveMono16(src, out, tmp_line, coeff, width, height);
  convolveMono16(out, src, tmp_line, coeff, height, width);
}

module.exports = blurMono16;

},{}],19:[function(_dereq_,module,exports){
if (typeof Object.create === 'function') {
  // implementation from standard node.js 'util' module
  module.exports = function inherits(ctor, superCtor) {
    if (superCtor) {
      ctor.super_ = superCtor;
      ctor.prototype = Object.create(superCtor.prototype, {
        constructor: {
          value: ctor,
          enumerable: false,
          writable: true,
          configurable: true
        }
      });
    }
  };
} else {
  // old school shim for old browsers
  module.exports = function inherits(ctor, superCtor) {
    if (superCtor) {
      ctor.super_ = superCtor;
      var TempCtor = function () {};
      TempCtor.prototype = superCtor.prototype;
      ctor.prototype = new TempCtor();
      ctor.prototype.constructor = ctor;
    }
  };
}

},{}],20:[function(_dereq_,module,exports){


var assign         = _dereq_('object-assign');
var base64decode   = _dereq_('./lib/base64decode');
var hasWebAssembly = _dereq_('./lib/wa_detect');


var DEFAULT_OPTIONS = {
  js: true,
  wasm: true
};


function MultiMath(options) {
  if (!(this instanceof MultiMath)) return new MultiMath(options);

  var opts = assign({}, DEFAULT_OPTIONS, options || {});

  this.options         = opts;

  this.__cache         = {};

  this.__init_promise  = null;
  this.__modules       = opts.modules || {};
  this.__memory        = null;
  this.__wasm          = {};

  this.__isLE = ((new Uint32Array((new Uint8Array([ 1, 0, 0, 0 ])).buffer))[0] === 1);

  if (!this.options.js && !this.options.wasm) {
    throw new Error('mathlib: at least "js" or "wasm" should be enabled');
  }
}


MultiMath.prototype.has_wasm = hasWebAssembly;


MultiMath.prototype.use = function (module) {
  this.__modules[module.name] = module;

  // Pin the best possible implementation
  if (this.options.wasm && this.has_wasm() && module.wasm_fn) {
    this[module.name] = module.wasm_fn;
  } else {
    this[module.name] = module.fn;
  }

  return this;
};


MultiMath.prototype.init = function () {
  if (this.__init_promise) return this.__init_promise;

  if (!this.options.js && this.options.wasm && !this.has_wasm()) {
    return Promise.reject(new Error('mathlib: only "wasm" was enabled, but it\'s not supported'));
  }

  var self = this;

  this.__init_promise = Promise.all(Object.keys(self.__modules).map(function (name) {
    var module = self.__modules[name];

    if (!self.options.wasm || !self.has_wasm() || !module.wasm_fn) return null;

    // If already compiled - exit
    if (self.__wasm[name]) return null;

    // Compile wasm source
    return WebAssembly.compile(self.__base64decode(module.wasm_src))
      .then(function (m) { self.__wasm[name] = m; });
  }))
    .then(function () { return self; });

  return this.__init_promise;
};


////////////////////////////////////////////////////////////////////////////////
// Methods below are for internal use from plugins


// Simple decode base64 to typed array. Useful to load embedded webassembly
// code. You probably don't need to call this method directly.
//
MultiMath.prototype.__base64decode = base64decode;


// Increase current memory to include specified number of bytes. Do nothing if
// size is already ok. You probably don't need to call this method directly,
// because it will be invoked from `.__instance()`.
//
MultiMath.prototype.__reallocate = function mem_grow_to(bytes) {
  if (!this.__memory) {
    this.__memory = new WebAssembly.Memory({
      initial: Math.ceil(bytes / (64 * 1024))
    });
    return this.__memory;
  }

  var mem_size = this.__memory.buffer.byteLength;

  if (mem_size < bytes) {
    this.__memory.grow(Math.ceil((bytes - mem_size) / (64 * 1024)));
  }

  return this.__memory;
};


// Returns instantinated webassembly item by name, with specified memory size
// and environment.
// - use cache if available
// - do sync module init, if async init was not called earlier
// - allocate memory if not enougth
// - can export functions to webassembly via "env_extra",
//   for example, { exp: Math.exp }
//
MultiMath.prototype.__instance = function instance(name, memsize, env_extra) {
  if (memsize) this.__reallocate(memsize);

  // If .init() was not called, do sync compile
  if (!this.__wasm[name]) {
    var module = this.__modules[name];
    this.__wasm[name] = new WebAssembly.Module(this.__base64decode(module.wasm_src));
  }

  if (!this.__cache[name]) {
    var env_base = {
      memoryBase: 0,
      memory: this.__memory,
      tableBase: 0,
      table: new WebAssembly.Table({ initial: 0, element: 'anyfunc' })
    };

    this.__cache[name] = new WebAssembly.Instance(this.__wasm[name], {
      env: assign(env_base, env_extra || {})
    });
  }

  return this.__cache[name];
};


// Helper to calculate memory aligh for pointers. Webassembly does not require
// this, but you may wish to experiment. Default base = 8;
//
MultiMath.prototype.__align = function align(number, base) {
  base = base || 8;
  var reminder = number % base;
  return number + (reminder ? base - reminder : 0);
};


module.exports = MultiMath;

},{"./lib/base64decode":21,"./lib/wa_detect":22,"object-assign":23}],21:[function(_dereq_,module,exports){


var BASE64_MAP = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';


module.exports = function base64decode(str) {
  var input = str.replace(/[\r\n=]/g, ''), // remove CR/LF & padding to simplify scan
      max   = input.length;

  var out = new Uint8Array((max * 3) >> 2);

  // Collect by 6*4 bits (3 bytes)

  var bits = 0;
  var ptr  = 0;

  for (var idx = 0; idx < max; idx++) {
    if ((idx % 4 === 0) && idx) {
      out[ptr++] = (bits >> 16) & 0xFF;
      out[ptr++] = (bits >> 8) & 0xFF;
      out[ptr++] = bits & 0xFF;
    }

    bits = (bits << 6) | BASE64_MAP.indexOf(input.charAt(idx));
  }

  // Dump tail

  var tailbits = (max % 4) * 6;

  if (tailbits === 0) {
    out[ptr++] = (bits >> 16) & 0xFF;
    out[ptr++] = (bits >> 8) & 0xFF;
    out[ptr++] = bits & 0xFF;
  } else if (tailbits === 18) {
    out[ptr++] = (bits >> 10) & 0xFF;
    out[ptr++] = (bits >> 2) & 0xFF;
  } else if (tailbits === 12) {
    out[ptr++] = (bits >> 4) & 0xFF;
  }

  return out;
};

},{}],22:[function(_dereq_,module,exports){


var wa;


module.exports = function hasWebAssembly() {
  // use cache if called before;
  if (typeof wa !== 'undefined') return wa;

  wa = false;

  if (typeof WebAssembly === 'undefined') return wa;

  // If WebAssenbly is disabled, code can throw on compile
  try {
    // https://github.com/brion/min-wasm-fail/blob/master/min-wasm-fail.in.js
    // Additional check that WA internals are correct

    /* eslint-disable comma-spacing, max-len */
    var bin      = new Uint8Array([ 0,97,115,109,1,0,0,0,1,6,1,96,1,127,1,127,3,2,1,0,5,3,1,0,1,7,8,1,4,116,101,115,116,0,0,10,16,1,14,0,32,0,65,1,54,2,0,32,0,40,2,0,11 ]);
    var module   = new WebAssembly.Module(bin);
    var instance = new WebAssembly.Instance(module, {});

    // test storing to and loading from a non-zero location via a parameter.
    // Safari on iOS 11.2.5 returns 0 unexpectedly at non-zero locations
    if (instance.exports.test(4) !== 0) wa = true;

    return wa;
  } catch (__) {}

  return wa;
};

},{}],23:[function(_dereq_,module,exports){
/* eslint-disable no-unused-vars */
var getOwnPropertySymbols = Object.getOwnPropertySymbols;
var hasOwnProperty = Object.prototype.hasOwnProperty;
var propIsEnumerable = Object.prototype.propertyIsEnumerable;

function toObject(val) {
	if (val === null || val === undefined) {
		throw new TypeError('Object.assign cannot be called with null or undefined');
	}

	return Object(val);
}

function shouldUseNative() {
	try {
		if (!Object.assign) {
			return false;
		}

		// Detect buggy property enumeration order in older V8 versions.

		// https://bugs.chromium.org/p/v8/issues/detail?id=4118
		var test1 = new String('abc');  // eslint-disable-line no-new-wrappers
		test1[5] = 'de';
		if (Object.getOwnPropertyNames(test1)[0] === '5') {
			return false;
		}

		// https://bugs.chromium.org/p/v8/issues/detail?id=3056
		var test2 = {};
		for (var i = 0; i < 10; i++) {
			test2['_' + String.fromCharCode(i)] = i;
		}
		var order2 = Object.getOwnPropertyNames(test2).map(function (n) {
			return test2[n];
		});
		if (order2.join('') !== '0123456789') {
			return false;
		}

		// https://bugs.chromium.org/p/v8/issues/detail?id=3056
		var test3 = {};
		'abcdefghijklmnopqrst'.split('').forEach(function (letter) {
			test3[letter] = letter;
		});
		if (Object.keys(Object.assign({}, test3)).join('') !==
				'abcdefghijklmnopqrst') {
			return false;
		}

		return true;
	} catch (err) {
		// We don't expect any of the above to throw, but better to be safe.
		return false;
	}
}

module.exports = shouldUseNative() ? Object.assign : function (target, source) {
	var from;
	var to = toObject(target);
	var symbols;

	for (var s = 1; s < arguments.length; s++) {
		from = Object(arguments[s]);

		for (var key in from) {
			if (hasOwnProperty.call(from, key)) {
				to[key] = from[key];
			}
		}

		if (getOwnPropertySymbols) {
			symbols = getOwnPropertySymbols(from);
			for (var i = 0; i < symbols.length; i++) {
				if (propIsEnumerable.call(from, symbols[i])) {
					to[symbols[i]] = from[symbols[i]];
				}
			}
		}
	}

	return to;
};

},{}],24:[function(_dereq_,module,exports){
var bundleFn = arguments[3];
var sources = arguments[4];
var cache = arguments[5];

var stringify = JSON.stringify;

module.exports = function (fn, options) {
    var wkey;
    var cacheKeys = Object.keys(cache);

    for (var i = 0, l = cacheKeys.length; i < l; i++) {
        var key = cacheKeys[i];
        var exp = cache[key].exports;
        // Using babel as a transpiler to use esmodule, the export will always
        // be an object with the default export as a property of it. To ensure
        // the existing api and babel esmodule exports are both supported we
        // check for both
        if (exp === fn || exp && exp.default === fn) {
            wkey = key;
            break;
        }
    }

    if (!wkey) {
        wkey = Math.floor(Math.pow(16, 8) * Math.random()).toString(16);
        var wcache = {};
        for (var i = 0, l = cacheKeys.length; i < l; i++) {
            var key = cacheKeys[i];
            wcache[key] = key;
        }
        sources[wkey] = [
            'function(require,module,exports){' + fn + '(self); }',
            wcache
        ];
    }
    var skey = Math.floor(Math.pow(16, 8) * Math.random()).toString(16);

    var scache = {}; scache[wkey] = wkey;
    sources[skey] = [
        'function(require,module,exports){' +
            // try to call default if defined to also support babel esmodule exports
            'var f = require(' + stringify(wkey) + ');' +
            '(f.default ? f.default : f)(self);' +
        '}',
        scache
    ];

    var workerSources = {};
    resolveSources(skey);

    function resolveSources(key) {
        workerSources[key] = true;

        for (var depPath in sources[key][1]) {
            var depKey = sources[key][1][depPath];
            if (!workerSources[depKey]) {
                resolveSources(depKey);
            }
        }
    }

    var src = '(' + bundleFn + ')({'
        + Object.keys(workerSources).map(function (key) {
            return stringify(key) + ':['
                + sources[key][0]
                + ',' + stringify(sources[key][1]) + ']'
            ;
        }).join(',')
        + '},{},[' + stringify(skey) + '])'
    ;

    var URL = window.URL || window.webkitURL || window.mozURL || window.msURL;

    var blob = new Blob([src], { type: 'text/javascript' });
    if (options && options.bare) { return blob; }
    var workerUrl = URL.createObjectURL(blob);
    var worker = new Worker(workerUrl);
    worker.objectURL = workerUrl;
    return worker;
};

},{}],"/index.js":[function(_dereq_,module,exports){

function _slicedToArray(arr, i) { return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _unsupportedIterableToArray(arr, i) || _nonIterableRest(); }

function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); }

function _unsupportedIterableToArray(o, minLen) { if (!o) return; if (typeof o === "string") return _arrayLikeToArray(o, minLen); var n = Object.prototype.toString.call(o).slice(8, -1); if (n === "Object" && o.constructor) n = o.constructor.name; if (n === "Map" || n === "Set") return Array.from(o); if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen); }

function _arrayLikeToArray(arr, len) { if (len == null || len > arr.length) len = arr.length; for (var i = 0, arr2 = new Array(len); i < len; i++) { arr2[i] = arr[i]; } return arr2; }

function _iterableToArrayLimit(arr, i) { var _i = arr == null ? null : typeof Symbol !== "undefined" && arr[Symbol.iterator] || arr["@@iterator"]; if (_i == null) return; var _arr = []; var _n = true; var _d = false; var _s, _e; try { for (_i = _i.call(arr); !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"] != null) _i["return"](); } finally { if (_d) throw _e; } } return _arr; }

function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }

var assign = _dereq_('object-assign');

var webworkify = _dereq_('webworkify');

var MathLib = _dereq_('./lib/mathlib');

var Pool = _dereq_('./lib/pool');

var utils = _dereq_('./lib/utils');

var worker = _dereq_('./lib/worker');

var createStages = _dereq_('./lib/stepper');

var createRegions = _dereq_('./lib/tiler'); // Deduplicate pools & limiters with the same configs
// when user creates multiple pica instances.


var singletones = {};
var NEED_SAFARI_FIX = false;

try {
  if (typeof navigator !== 'undefined' && navigator.userAgent) {
    NEED_SAFARI_FIX = navigator.userAgent.indexOf('Safari') >= 0;
  }
} catch (e) {}

var concurrency = 1;

if (typeof navigator !== 'undefined') {
  concurrency = Math.min(navigator.hardwareConcurrency || 1, 4);
}

var DEFAULT_PICA_OPTS = {
  tile: 1024,
  concurrency: concurrency,
  features: ['js', 'wasm', 'ww'],
  idle: 2000,
  createCanvas: function createCanvas(width, height) {
    var tmpCanvas = document.createElement('canvas');
    tmpCanvas.width = width;
    tmpCanvas.height = height;
    return tmpCanvas;
  }
};
var DEFAULT_RESIZE_OPTS = {
  quality: 3,
  alpha: false,
  unsharpAmount: 0,
  unsharpRadius: 0.0,
  unsharpThreshold: 0
};
var CAN_NEW_IMAGE_DATA = false;
var CAN_CREATE_IMAGE_BITMAP = false;
var CAN_USE_CANVAS_GET_IMAGE_DATA = false;
var CAN_USE_OFFSCREEN_CANVAS = false;
var CAN_USE_CIB_REGION_FOR_IMAGE = false;

function workerFabric() {
  return {
    value: webworkify(worker),
    destroy: function destroy() {
      this.value.terminate();

      if (typeof window !== 'undefined') {
        var url = window.URL || window.webkitURL || window.mozURL || window.msURL;

        if (url && url.revokeObjectURL && this.value.objectURL) {
          url.revokeObjectURL(this.value.objectURL);
        }
      }
    }
  };
} ////////////////////////////////////////////////////////////////////////////////
// API methods


function Pica(options) {
  if (!(this instanceof Pica)) return new Pica(options);
  this.options = assign({}, DEFAULT_PICA_OPTS, options || {});
  var limiter_key = "lk_".concat(this.options.concurrency); // Share limiters to avoid multiple parallel workers when user creates
  // multiple pica instances.

  this.__limit = singletones[limiter_key] || utils.limiter(this.options.concurrency);
  if (!singletones[limiter_key]) singletones[limiter_key] = this.__limit; // List of supported features, according to options & browser/node.js

  this.features = {
    js: false,
    // pure JS implementation, can be disabled for testing
    wasm: false,
    // webassembly implementation for heavy functions
    cib: false,
    // resize via createImageBitmap (only FF at this moment)
    ww: false // webworkers

  };
  this.__workersPool = null; // Store requested features for webworkers

  this.__requested_features = [];
  this.__mathlib = null;
}

Pica.prototype.init = function () {
  var _this = this;

  if (this.__initPromise) return this.__initPromise; // Test if we can create ImageData without canvas and memory copy

  if (typeof ImageData !== 'undefined' && typeof Uint8ClampedArray !== 'undefined') {
    try {
      /* eslint-disable no-new */
      new ImageData(new Uint8ClampedArray(400), 10, 10);
      CAN_NEW_IMAGE_DATA = true;
    } catch (__) {}
  } // ImageBitmap can be effective in 2 places:
  //
  // 1. Threaded jpeg unpack (basic)
  // 2. Built-in resize (blocked due problem in chrome, see issue #89)
  //
  // For basic use we also need ImageBitmap wo support .close() method,
  // see https://developer.mozilla.org/ru/docs/Web/API/ImageBitmap


  if (typeof ImageBitmap !== 'undefined') {
    if (ImageBitmap.prototype && ImageBitmap.prototype.close) {
      CAN_CREATE_IMAGE_BITMAP = true;
    } else {
      this.debug('ImageBitmap does not support .close(), disabled');
    }
  }

  var features = this.options.features.slice();

  if (features.indexOf('all') >= 0) {
    features = ['cib', 'wasm', 'js', 'ww'];
  }

  this.__requested_features = features;
  this.__mathlib = new MathLib(features); // Check WebWorker support if requested

  if (features.indexOf('ww') >= 0) {
    if (typeof window !== 'undefined' && 'Worker' in window) {
      // IE <= 11 don't allow to create webworkers from string. We should check it.
      // https://connect.microsoft.com/IE/feedback/details/801810/web-workers-from-blob-urls-in-ie-10-and-11
      try {
        var wkr = _dereq_('webworkify')(function () {});

        wkr.terminate();
        this.features.ww = true; // pool uniqueness depends on pool config + webworker config

        var wpool_key = "wp_".concat(JSON.stringify(this.options));

        if (singletones[wpool_key]) {
          this.__workersPool = singletones[wpool_key];
        } else {
          this.__workersPool = new Pool(workerFabric, this.options.idle);
          singletones[wpool_key] = this.__workersPool;
        }
      } catch (__) {}
    }
  }

  var initMath = this.__mathlib.init().then(function (mathlib) {
    // Copy detected features
    assign(_this.features, mathlib.features);
  });

  var checkCibResize;

  if (!CAN_CREATE_IMAGE_BITMAP) {
    checkCibResize = Promise.resolve(false);
  } else {
    checkCibResize = utils.cib_support(this.options.createCanvas).then(function (status) {
      if (_this.features.cib && features.indexOf('cib') < 0) {
        _this.debug('createImageBitmap() resize supported, but disabled by config');

        return;
      }

      if (features.indexOf('cib') >= 0) _this.features.cib = status;
    });
  }

  CAN_USE_CANVAS_GET_IMAGE_DATA = utils.can_use_canvas(this.options.createCanvas);
  var checkOffscreenCanvas;

  if (CAN_CREATE_IMAGE_BITMAP && CAN_NEW_IMAGE_DATA && features.indexOf('ww') !== -1) {
    checkOffscreenCanvas = utils.worker_offscreen_canvas_support();
  } else {
    checkOffscreenCanvas = Promise.resolve(false);
  }

  checkOffscreenCanvas = checkOffscreenCanvas.then(function (result) {
    CAN_USE_OFFSCREEN_CANVAS = result;
  }); // we use createImageBitmap to crop image data and pass it to workers,
  // so need to check whether function works correctly;
  // https://bugs.chromium.org/p/chromium/issues/detail?id=1220671

  var checkCibRegion = utils.cib_can_use_region().then(function (result) {
    CAN_USE_CIB_REGION_FOR_IMAGE = result;
  }); // Init math lib. That's async because can load some

  this.__initPromise = Promise.all([initMath, checkCibResize, checkOffscreenCanvas, checkCibRegion]).then(function () {
    return _this;
  });
  return this.__initPromise;
}; // Call resizer in webworker or locally, depending on config


Pica.prototype.__invokeResize = function (tileOpts, opts) {
  var _this2 = this;

  // Share cache between calls:
  //
  // - wasm instance
  // - wasm memory object
  //
  opts.__mathCache = opts.__mathCache || {};
  return Promise.resolve().then(function () {
    if (!_this2.features.ww) {
      // not possible to have ImageBitmap here if user disabled WW
      return {
        data: _this2.__mathlib.resizeAndUnsharp(tileOpts, opts.__mathCache)
      };
    }

    return new Promise(function (resolve, reject) {
      var w = _this2.__workersPool.acquire();

      if (opts.cancelToken) opts.cancelToken["catch"](function (err) {
        return reject(err);
      });

      w.value.onmessage = function (ev) {
        w.release();
        if (ev.data.err) reject(ev.data.err);else resolve(ev.data);
      };

      var transfer = [];
      if (tileOpts.src) transfer.push(tileOpts.src.buffer);
      if (tileOpts.srcBitmap) transfer.push(tileOpts.srcBitmap);
      w.value.postMessage({
        opts: tileOpts,
        features: _this2.__requested_features,
        preload: {
          wasm_nodule: _this2.__mathlib.__
        }
      }, transfer);
    });
  });
}; // this function can return promise if createImageBitmap is used


Pica.prototype.__extractTileData = function (tile, from, opts, stageEnv, extractTo) {
  if (this.features.ww && CAN_USE_OFFSCREEN_CANVAS && ( // createImageBitmap doesn't work for images (Image, ImageBitmap) with Exif orientation in Chrome,
  // can use canvas because canvas doesn't have orientation;
  // see https://bugs.chromium.org/p/chromium/issues/detail?id=1220671
  utils.isCanvas(from) || CAN_USE_CIB_REGION_FOR_IMAGE)) {
    this.debug('Create tile for OffscreenCanvas');
    return createImageBitmap(stageEnv.srcImageBitmap || from, tile.x, tile.y, tile.width, tile.height).then(function (bitmap) {
      extractTo.srcBitmap = bitmap;
      return extractTo;
    });
  } // Extract tile RGBA buffer, depending on input type


  if (utils.isCanvas(from)) {
    if (!stageEnv.srcCtx) stageEnv.srcCtx = from.getContext('2d', {
      alpha: Boolean(opts.alpha)
    }); // If input is Canvas - extract region data directly

    this.debug('Get tile pixel data');
    extractTo.src = stageEnv.srcCtx.getImageData(tile.x, tile.y, tile.width, tile.height).data;
    return extractTo;
  } // If input is Image or decoded to ImageBitmap,
  // draw region to temporary canvas and extract data from it
  //
  // Note! Attempt to reuse this canvas causes significant slowdown in chrome
  //


  this.debug('Draw tile imageBitmap/image to temporary canvas');
  var tmpCanvas = this.options.createCanvas(tile.width, tile.height);
  var tmpCtx = tmpCanvas.getContext('2d', {
    alpha: Boolean(opts.alpha)
  });
  tmpCtx.globalCompositeOperation = 'copy';
  tmpCtx.drawImage(stageEnv.srcImageBitmap || from, tile.x, tile.y, tile.width, tile.height, 0, 0, tile.width, tile.height);
  this.debug('Get tile pixel data');
  extractTo.src = tmpCtx.getImageData(0, 0, tile.width, tile.height).data; // Safari 12 workaround
  // https://github.com/nodeca/pica/issues/199

  tmpCanvas.width = tmpCanvas.height = 0;
  return extractTo;
};

Pica.prototype.__landTileData = function (tile, result, stageEnv) {
  var toImageData;
  this.debug('Convert raw rgba tile result to ImageData');

  if (result.bitmap) {
    stageEnv.toCtx.drawImage(result.bitmap, tile.toX, tile.toY);
    return null;
  }

  if (CAN_NEW_IMAGE_DATA) {
    // this branch is for modern browsers
    // If `new ImageData()` & Uint8ClampedArray suported
    toImageData = new ImageData(new Uint8ClampedArray(result.data), tile.toWidth, tile.toHeight);
  } else {
    // fallback for `node-canvas` and old browsers
    // (IE11 has ImageData but does not support `new ImageData()`)
    toImageData = stageEnv.toCtx.createImageData(tile.toWidth, tile.toHeight);

    if (toImageData.data.set) {
      toImageData.data.set(result.data);
    } else {
      // IE9 don't have `.set()`
      for (var i = toImageData.data.length - 1; i >= 0; i--) {
        toImageData.data[i] = result.data[i];
      }
    }
  }

  this.debug('Draw tile');

  if (NEED_SAFARI_FIX) {
    // Safari draws thin white stripes between tiles without this fix
    stageEnv.toCtx.putImageData(toImageData, tile.toX, tile.toY, tile.toInnerX - tile.toX, tile.toInnerY - tile.toY, tile.toInnerWidth + 1e-5, tile.toInnerHeight + 1e-5);
  } else {
    stageEnv.toCtx.putImageData(toImageData, tile.toX, tile.toY, tile.toInnerX - tile.toX, tile.toInnerY - tile.toY, tile.toInnerWidth, tile.toInnerHeight);
  }

  return null;
};

Pica.prototype.__tileAndResize = function (from, to, opts) {
  var _this3 = this;

  var stageEnv = {
    srcCtx: null,
    srcImageBitmap: null,
    isImageBitmapReused: false,
    toCtx: null
  };

  var processTile = function processTile(tile) {
    return _this3.__limit(function () {
      if (opts.canceled) return opts.cancelToken;
      var tileOpts = {
        width: tile.width,
        height: tile.height,
        toWidth: tile.toWidth,
        toHeight: tile.toHeight,
        scaleX: tile.scaleX,
        scaleY: tile.scaleY,
        offsetX: tile.offsetX,
        offsetY: tile.offsetY,
        quality: opts.quality,
        alpha: opts.alpha,
        unsharpAmount: opts.unsharpAmount,
        unsharpRadius: opts.unsharpRadius,
        unsharpThreshold: opts.unsharpThreshold
      };

      _this3.debug('Invoke resize math');

      return Promise.resolve(tileOpts).then(function (tileOpts) {
        return _this3.__extractTileData(tile, from, opts, stageEnv, tileOpts);
      }).then(function (tileOpts) {
        _this3.debug('Invoke resize math');

        return _this3.__invokeResize(tileOpts, opts);
      }).then(function (result) {
        if (opts.canceled) return opts.cancelToken;
        stageEnv.srcImageData = null;
        return _this3.__landTileData(tile, result, stageEnv);
      });
    });
  }; // Need to normalize data source first. It can be canvas or image.
  // If image - try to decode in background if possible


  return Promise.resolve().then(function () {
    stageEnv.toCtx = to.getContext('2d', {
      alpha: Boolean(opts.alpha)
    });
    if (utils.isCanvas(from)) return null;

    if (utils.isImageBitmap(from)) {
      stageEnv.srcImageBitmap = from;
      stageEnv.isImageBitmapReused = true;
      return null;
    }

    if (utils.isImage(from)) {
      // try do decode image in background for faster next operations;
      // if we're using offscreen canvas, cib is called per tile, so not needed here
      if (!CAN_CREATE_IMAGE_BITMAP) return null;

      _this3.debug('Decode image via createImageBitmap');

      return createImageBitmap(from).then(function (imageBitmap) {
        stageEnv.srcImageBitmap = imageBitmap;
      }) // Suppress error to use fallback, if method fails
      // https://github.com/nodeca/pica/issues/190

      /* eslint-disable no-unused-vars */
      ["catch"](function (e) {
        return null;
      });
    }

    throw new Error('Pica: ".from" should be Image, Canvas or ImageBitmap');
  }).then(function () {
    if (opts.canceled) return opts.cancelToken;

    _this3.debug('Calculate tiles'); //
    // Here we are with "normalized" source,
    // follow to tiling
    //


    var regions = createRegions({
      width: opts.width,
      height: opts.height,
      srcTileSize: _this3.options.tile,
      toWidth: opts.toWidth,
      toHeight: opts.toHeight,
      destTileBorder: opts.__destTileBorder
    });
    var jobs = regions.map(function (tile) {
      return processTile(tile);
    });

    function cleanup(stageEnv) {
      if (stageEnv.srcImageBitmap) {
        if (!stageEnv.isImageBitmapReused) stageEnv.srcImageBitmap.close();
        stageEnv.srcImageBitmap = null;
      }
    }

    _this3.debug('Process tiles');

    return Promise.all(jobs).then(function () {
      _this3.debug('Finished!');

      cleanup(stageEnv);
      return to;
    }, function (err) {
      cleanup(stageEnv);
      throw err;
    });
  });
};

Pica.prototype.__processStages = function (stages, from, to, opts) {
  var _this4 = this;

  if (opts.canceled) return opts.cancelToken;

  var _stages$shift = stages.shift(),
      _stages$shift2 = _slicedToArray(_stages$shift, 2),
      toWidth = _stages$shift2[0],
      toHeight = _stages$shift2[1];

  var isLastStage = stages.length === 0;
  opts = assign({}, opts, {
    toWidth: toWidth,
    toHeight: toHeight,
    // only use user-defined quality for the last stage,
    // use simpler (Hamming) filter for the first stages where
    // scale factor is large enough (more than 2-3)
    quality: isLastStage ? opts.quality : Math.min(1, opts.quality)
  });
  var tmpCanvas;

  if (!isLastStage) {
    // create temporary canvas
    tmpCanvas = this.options.createCanvas(toWidth, toHeight);
  }

  return this.__tileAndResize(from, isLastStage ? to : tmpCanvas, opts).then(function () {
    if (isLastStage) return to;
    opts.width = toWidth;
    opts.height = toHeight;
    return _this4.__processStages(stages, tmpCanvas, to, opts);
  }).then(function (res) {
    if (tmpCanvas) {
      // Safari 12 workaround
      // https://github.com/nodeca/pica/issues/199
      tmpCanvas.width = tmpCanvas.height = 0;
    }

    return res;
  });
};

Pica.prototype.__resizeViaCreateImageBitmap = function (from, to, opts) {
  var _this5 = this;

  var toCtx = to.getContext('2d', {
    alpha: Boolean(opts.alpha)
  });
  this.debug('Resize via createImageBitmap()');
  return createImageBitmap(from, {
    resizeWidth: opts.toWidth,
    resizeHeight: opts.toHeight,
    resizeQuality: utils.cib_quality_name(opts.quality)
  }).then(function (imageBitmap) {
    if (opts.canceled) return opts.cancelToken; // if no unsharp - draw directly to output canvas

    if (!opts.unsharpAmount) {
      toCtx.drawImage(imageBitmap, 0, 0);
      imageBitmap.close();
      toCtx = null;

      _this5.debug('Finished!');

      return to;
    }

    _this5.debug('Unsharp result');

    var tmpCanvas = _this5.options.createCanvas(opts.toWidth, opts.toHeight);

    var tmpCtx = tmpCanvas.getContext('2d', {
      alpha: Boolean(opts.alpha)
    });
    tmpCtx.drawImage(imageBitmap, 0, 0);
    imageBitmap.close();
    var iData = tmpCtx.getImageData(0, 0, opts.toWidth, opts.toHeight);

    _this5.__mathlib.unsharp_mask(iData.data, opts.toWidth, opts.toHeight, opts.unsharpAmount, opts.unsharpRadius, opts.unsharpThreshold);

    toCtx.putImageData(iData, 0, 0); // Safari 12 workaround
    // https://github.com/nodeca/pica/issues/199

    tmpCanvas.width = tmpCanvas.height = 0;
    iData = tmpCtx = tmpCanvas = toCtx = null;

    _this5.debug('Finished!');

    return to;
  });
};

Pica.prototype.resize = function (from, to, options) {
  var _this6 = this;

  this.debug('Start resize...');
  var opts = assign({}, DEFAULT_RESIZE_OPTS);

  if (!isNaN(options)) {
    opts = assign(opts, {
      quality: options
    });
  } else if (options) {
    opts = assign(opts, options);
  }

  opts.toWidth = to.width;
  opts.toHeight = to.height;
  opts.width = from.naturalWidth || from.width;
  opts.height = from.naturalHeight || from.height; // Prevent stepper from infinite loop

  if (to.width === 0 || to.height === 0) {
    return Promise.reject(new Error("Invalid output size: ".concat(to.width, "x").concat(to.height)));
  }

  if (opts.unsharpRadius > 2) opts.unsharpRadius = 2;
  opts.canceled = false;

  if (opts.cancelToken) {
    // Wrap cancelToken to avoid successive resolve & set flag
    opts.cancelToken = opts.cancelToken.then(function (data) {
      opts.canceled = true;
      throw data;
    }, function (err) {
      opts.canceled = true;
      throw err;
    });
  }

  var DEST_TILE_BORDER = 3; // Max possible filter window size

  opts.__destTileBorder = Math.ceil(Math.max(DEST_TILE_BORDER, 2.5 * opts.unsharpRadius | 0));
  return this.init().then(function () {
    if (opts.canceled) return opts.cancelToken; // if createImageBitmap supports resize, just do it and return

    if (_this6.features.cib) {
      return _this6.__resizeViaCreateImageBitmap(from, to, opts);
    }

    if (!CAN_USE_CANVAS_GET_IMAGE_DATA) {
      var err = new Error('Pica: cannot use getImageData on canvas, ' + "make sure fingerprinting protection isn't enabled");
      err.code = 'ERR_GET_IMAGE_DATA';
      throw err;
    } //
    // No easy way, let's resize manually via arrays
    //


    var stages = createStages(opts.width, opts.height, opts.toWidth, opts.toHeight, _this6.options.tile, opts.__destTileBorder);
    return _this6.__processStages(stages, from, to, opts);
  });
}; // RGBA buffer resize
//


Pica.prototype.resizeBuffer = function (options) {
  var _this7 = this;

  var opts = assign({}, DEFAULT_RESIZE_OPTS, options);
  return this.init().then(function () {
    return _this7.__mathlib.resizeAndUnsharp(opts);
  });
};

Pica.prototype.toBlob = function (canvas, mimeType, quality) {
  mimeType = mimeType || 'image/png';
  return new Promise(function (resolve) {
    if (canvas.toBlob) {
      canvas.toBlob(function (blob) {
        return resolve(blob);
      }, mimeType, quality);
      return;
    }

    if (canvas.convertToBlob) {
      resolve(canvas.convertToBlob({
        type: mimeType,
        quality: quality
      }));
      return;
    } // Fallback for old browsers


    var asString = atob(canvas.toDataURL(mimeType, quality).split(',')[1]);
    var len = asString.length;
    var asBuffer = new Uint8Array(len);

    for (var i = 0; i < len; i++) {
      asBuffer[i] = asString.charCodeAt(i);
    }

    resolve(new Blob([asBuffer], {
      type: mimeType
    }));
  });
};

Pica.prototype.debug = function () {};

module.exports = Pica;

},{"./lib/mathlib":1,"./lib/pool":13,"./lib/stepper":14,"./lib/tiler":15,"./lib/utils":16,"./lib/worker":17,"object-assign":23,"webworkify":24}]},{},[])("/index.js")
});
});

var image_traverse = createCommonjsModule(function (module) {

//////////////////////////////////////////////////////////////////////////
// Helpers
//
function error(message, code) {
  var err = new Error(message);
  err.code = code;
  return err;
}


// Convert number to 0xHH string
//
function to_hex(number) {
  var n = number.toString(16).toUpperCase();
  for (var i = 2 - n.length; i > 0; i--) n = '0' + n;
  return '0x' + n;
}


function utf8_encode(str) {
  try {
    return unescape(encodeURIComponent(str));
  } catch (_) {
    return str;
  }
}


function utf8_decode(str) {
  try {
    return decodeURIComponent(escape(str));
  } catch (_) {
    return str;
  }
}


// Check if input is a Uint8Array
//
function is_uint8array(bin) {
  return Object.prototype.toString.call(bin) === '[object Uint8Array]';
}


//////////////////////////////////////////////////////////////////////////
// Exif parser
//
// Input:
//  - jpeg_bin:   Uint8Array - jpeg file
//  - exif_start: Number     - start of TIFF header (after Exif\0\0)
//  - exif_end:   Number     - end of Exif segment
//  - on_entry:   Number     - callback
//
function ExifParser(jpeg_bin, exif_start, exif_end) {
  // Uint8Array, exif without signature (which isn't included in offsets)
  this.input      = jpeg_bin.subarray(exif_start, exif_end);

  // offset correction for `on_entry` callback
  this.start      = exif_start;

  // Check TIFF header (includes byte alignment and first IFD offset)
  var sig = String.fromCharCode.apply(null, this.input.subarray(0, 4));

  if (sig !== 'II\x2A\0' && sig !== 'MM\0\x2A') {
    throw error('invalid TIFF signature', 'EBADDATA');
  }

  // true if motorola (big endian) byte alignment, false if intel
  this.big_endian = sig[0] === 'M';
}


ExifParser.prototype.each = function (on_entry) {
  // allow premature exit
  this.aborted = false;

  var offset = this.read_uint32(4);

  this.ifds_to_read = [ {
    id:     0,
    offset: offset
  } ];

  while (this.ifds_to_read.length > 0 && !this.aborted) {
    var i = this.ifds_to_read.shift();
    if (!i.offset) continue;
    this.scan_ifd(i.id, i.offset, on_entry);
  }
};


ExifParser.prototype.filter = function (on_entry) {
  var ifds = {};

  // make sure IFD0 always exists
  ifds.ifd0 = { id: 0, entries: [] };

  this.each(function (entry) {
    if (on_entry(entry) === false && !entry.is_subifd_link) return;
    if (entry.is_subifd_link && entry.count !== 1 && entry.format !== 4) return; // filter out bogus links

    if (!ifds['ifd' + entry.ifd]) {
      ifds['ifd' + entry.ifd] = { id: entry.ifd, entries: [] };
    }

    ifds['ifd' + entry.ifd].entries.push(entry);
  });

  // thumbnails are not supported just yet, so delete all information related to it
  delete ifds.ifd1;

  // Calculate output size
  var length = 8;
  Object.keys(ifds).forEach(function (ifd_no) {
    length += 2;

    ifds[ifd_no].entries.forEach(function (entry) {
      length += 12 + (entry.data_length > 4 ? Math.ceil(entry.data_length / 2) * 2 : 0);
    });

    length += 4;
  });

  this.output = new Uint8Array(length);
  this.output[0] = this.output[1] = (this.big_endian ? 'M' : 'I').charCodeAt(0);
  this.write_uint16(2, 0x2A);

  var offset = 8;
  var self = this;
  this.write_uint32(4, offset);

  Object.keys(ifds).forEach(function (ifd_no) {
    ifds[ifd_no].written_offset = offset;

    var ifd_start = offset;
    var ifd_end   = ifd_start + 2 + ifds[ifd_no].entries.length * 12 + 4;
    offset = ifd_end;

    self.write_uint16(ifd_start, ifds[ifd_no].entries.length);

    ifds[ifd_no].entries.sort(function (a, b) {
      // IFD entries must be in order of increasing tag IDs
      return a.tag - b.tag;
    }).forEach(function (entry, idx) {
      var entry_offset = ifd_start + 2 + idx * 12;

      self.write_uint16(entry_offset, entry.tag);
      self.write_uint16(entry_offset + 2, entry.format);
      self.write_uint32(entry_offset + 4, entry.count);

      if (entry.is_subifd_link) {
        // filled in later
        if (ifds['ifd' + entry.tag]) ifds['ifd' + entry.tag].link_offset = entry_offset + 8;
      } else if (entry.data_length <= 4) {
        self.output.set(
          self.input.subarray(entry.data_offset - self.start, entry.data_offset - self.start + 4),
          entry_offset + 8
        );
      } else {
        self.write_uint32(entry_offset + 8, offset);
        self.output.set(
          self.input.subarray(entry.data_offset - self.start, entry.data_offset - self.start + entry.data_length),
          offset
        );
        offset += Math.ceil(entry.data_length / 2) * 2;
      }
    });

    var next_ifd = ifds['ifd' + (ifds[ifd_no].id + 1)];
    if (next_ifd) next_ifd.link_offset = ifd_end - 4;
  });

  Object.keys(ifds).forEach(function (ifd_no) {
    if (ifds[ifd_no].written_offset && ifds[ifd_no].link_offset) {
      self.write_uint32(ifds[ifd_no].link_offset, ifds[ifd_no].written_offset);
    }
  });

  if (this.output.length !== offset) throw error('internal error: incorrect buffer size allocated');

  return this.output;
};


ExifParser.prototype.read_uint16 = function (offset) {
  var d = this.input;
  if (offset + 2 > d.length) throw error('unexpected EOF', 'EBADDATA');

  return this.big_endian ?
    d[offset] * 0x100 + d[offset + 1] :
    d[offset] + d[offset + 1] * 0x100;
};


ExifParser.prototype.read_uint32 = function (offset) {
  var d = this.input;
  if (offset + 4 > d.length) throw error('unexpected EOF', 'EBADDATA');

  return this.big_endian ?
    d[offset] * 0x1000000 + d[offset + 1] * 0x10000 + d[offset + 2] * 0x100 + d[offset + 3] :
    d[offset] + d[offset + 1] * 0x100 + d[offset + 2] * 0x10000 + d[offset + 3] * 0x1000000;
};


ExifParser.prototype.write_uint16 = function (offset, value) {
  var d = this.output;

  if (this.big_endian) {
    d[offset]     = (value >>> 8) & 0xFF;
    d[offset + 1] = value & 0xFF;
  } else {
    d[offset]     = value & 0xFF;
    d[offset + 1] = (value >>> 8) & 0xFF;
  }
};


ExifParser.prototype.write_uint32 = function (offset, value) {
  var d = this.output;

  if (this.big_endian) {
    d[offset]     = (value >>> 24) & 0xFF;
    d[offset + 1] = (value >>> 16) & 0xFF;
    d[offset + 2] = (value >>> 8) & 0xFF;
    d[offset + 3] = value & 0xFF;
  } else {
    d[offset]     = value & 0xFF;
    d[offset + 1] = (value >>> 8) & 0xFF;
    d[offset + 2] = (value >>> 16) & 0xFF;
    d[offset + 3] = (value >>> 24) & 0xFF;
  }
};


ExifParser.prototype.is_subifd_link = function (ifd, tag) {
  return (ifd === 0 && tag === 0x8769) || // SubIFD
         (ifd === 0 && tag === 0x8825) || // GPS Info
         (ifd === 0x8769 && tag === 0xA005); // Interop IFD
};


// Returns byte length of a single component of a given format
//
ExifParser.prototype.exif_format_length = function (format) {
  switch (format) {
    case 1: // byte
    case 2: // ascii
    case 6: // sbyte
    case 7: // undefined
      return 1;

    case 3: // short
    case 8: // sshort
      return 2;

    case 4:  // long
    case 9:  // slong
    case 11: // float
      return 4;

    case 5:  // rational
    case 10: // srational
    case 12: // double
      return 8;

    default:
      // unknown type
      return 0;
  }
};


// Reads Exif data
//
ExifParser.prototype.exif_format_read = function (format, offset) {
  var v;

  switch (format) {
    case 1: // byte
    case 2: // ascii
      v = this.input[offset];
      return v;

    case 6: // sbyte
      v = this.input[offset];
      return v | (v & 0x80) * 0x1fffffe;

    case 3: // short
      v = this.read_uint16(offset);
      return v;

    case 8: // sshort
      v = this.read_uint16(offset);
      return v | (v & 0x8000) * 0x1fffe;

    case 4: // long
      v = this.read_uint32(offset);
      return v;

    case 9: // slong
      v = this.read_uint32(offset);
      return v | 0;

    case 5:  // rational
    case 10: // srational
    case 11: // float
    case 12: // double
      return null; // not implemented

    case 7: // undefined
      return null; // blob

    default:
      // unknown type
      return null;
  }
};


ExifParser.prototype.scan_ifd = function (ifd_no, offset, on_entry) {
  var entry_count = this.read_uint16(offset);

  offset += 2;

  for (var i = 0; i < entry_count; i++) {
    var tag    = this.read_uint16(offset);
    var format = this.read_uint16(offset + 2);
    var count  = this.read_uint32(offset + 4);

    var comp_length    = this.exif_format_length(format);
    var data_length    = count * comp_length;
    var data_offset    = data_length <= 4 ? offset + 8 : this.read_uint32(offset + 8);
    var is_subifd_link = false;

    if (data_offset + data_length > this.input.length) {
      throw error('unexpected EOF', 'EBADDATA');
    }

    var value = [];
    var comp_offset = data_offset;

    for (var j = 0; j < count; j++, comp_offset += comp_length) {
      var item = this.exif_format_read(format, comp_offset);
      if (item === null) {
        value = null;
        break;
      }
      value.push(item);
    }

    if (Array.isArray(value) && format === 2) {
      try {
        value = utf8_decode(String.fromCharCode.apply(null, value));
      } catch (_) {
        value = null;
      }

      if (value && value[value.length - 1] === '\0') value = value.slice(0, -1);
    }

    if (this.is_subifd_link(ifd_no, tag)) {
      if (Array.isArray(value) && Number.isInteger(value[0]) && value[0] > 0) {
        this.ifds_to_read.push({
          id:     tag,
          offset: value[0]
        });
        is_subifd_link = true;
      }
    }

    var entry = {
      is_big_endian:  this.big_endian,
      ifd:            ifd_no,
      tag:            tag,
      format:         format,
      count:          count,
      entry_offset:   offset + this.start,
      data_length:    data_length,
      data_offset:    data_offset + this.start,
      value:          value,
      is_subifd_link: is_subifd_link
    };

    if (on_entry(entry) === false) {
      this.aborted = true;
      return;
    }

    offset += 12;
  }

  if (ifd_no === 0) {
    this.ifds_to_read.push({
      id:     1,
      offset: this.read_uint32(offset)
    });
  }
};


// Check whether input is a JPEG image
//
// Input:
//  - jpeg_bin: Uint8Array - jpeg file
//
// Returns true if it is and false otherwise
//
module.exports.is_jpeg = function (jpeg_bin) {
  return jpeg_bin.length >= 4 && jpeg_bin[0] === 0xFF && jpeg_bin[1] === 0xD8 && jpeg_bin[2] === 0xFF;
};


// Call an iterator on each segment in the given JPEG image
//
// Input:
//  - jpeg_bin:   Uint8Array - jpeg file
//  - on_segment: Function - callback executed on each JPEG marker segment
//    - segment:  Object
//      - code:   Number - marker type (2nd byte, e.g. 0xE0 for APP0)
//      - offset: Number - offset of the first byte (0xFF) relative to `jpeg_bin` start
//      - length: Number - length of the entire marker segment including first two bytes and length
//        - 2 for standalone markers
//        - 4+length for markers with data
//
// Iteration stops when `EOI` (0xFFD9) marker is reached or if `on_segment`
// function returns `false`.
//
module.exports.jpeg_segments_each = function (jpeg_bin, on_segment) {
  if (!is_uint8array(jpeg_bin)) {
    throw error('Invalid argument (jpeg_bin), Uint8Array expected', 'EINVAL');
  }

  if (typeof on_segment !== 'function') {
    throw error('Invalid argument (on_segment), Function expected', 'EINVAL');
  }

  if (!module.exports.is_jpeg(jpeg_bin)) {
    throw error('Unknown file format', 'ENOTJPEG');
  }

  var offset = 0, length = jpeg_bin.length, inside_scan = false;

  for (;;) {
    var segment_code, segment_length;

    if (offset + 1 >= length) throw error('Unexpected EOF', 'EBADDATA');
    var byte1 = jpeg_bin[offset];
    var byte2 = jpeg_bin[offset + 1];

    if (byte1 === 0xFF && byte2 === 0xFF) {
      // padding
      segment_code = 0xFF;
      segment_length = 1;

    } else if (byte1 === 0xFF && byte2 !== 0) {
      // marker
      segment_code = byte2;
      segment_length = 2;

      if ((0xD0 <= segment_code && segment_code <= 0xD9) || segment_code === 0x01) ; else {
        if (offset + 3 >= length) throw error('Unexpected EOF', 'EBADDATA');
        segment_length += jpeg_bin[offset + 2] * 0x100 + jpeg_bin[offset + 3];
        if (segment_length < 2) throw error('Invalid segment length', 'EBADDATA');
        if (offset + segment_length - 1 >= length) throw error('Unexpected EOF', 'EBADDATA');
      }

      if (inside_scan) {
        if (segment_code >= 0xD0 && segment_code <= 0xD7) ; else {
          inside_scan = false;
        }
      }

      if (segment_code === 0xDA /* SOS */) inside_scan = true;
    } else if (inside_scan) {
      // entropy-encoded segment
      for (var pos = offset + 1; ; pos++) {
        // scan until we find FF
        if (pos >= length) throw error('Unexpected EOF', 'EBADDATA');
        if (jpeg_bin[pos] === 0xFF) {
          if (pos + 1 >= length) throw error('Unexpected EOF', 'EBADDATA');
          if (jpeg_bin[pos + 1] !== 0) {
            segment_code = 0;
            segment_length = pos - offset;
            break;
          }
        }
      }
    } else {
      throw error('Unexpected byte at segment start: ' + to_hex(byte1) +
        ' (offset ' + to_hex(offset) + ')', 'EBADDATA');
    }

    if (on_segment({ code: segment_code, offset: offset, length: segment_length }) === false) break;
    if (segment_code === 0xD9 /* EOI */) break;
    offset += segment_length;
  }
};


// Replace or remove segments in the given JPEG image
//
// Input:
//  - jpeg_bin:   Uint8Array - jpeg file
//  - on_segment: Function - callback executed on each JPEG marker segment
//    - segment:  Object
//      - code:   Number - marker type (2nd byte, e.g. 0xE0 for APP0)
//      - offset: Number - offset of the first byte (0xFF) relative to `jpeg_bin` start
//      - length: Number - length of the entire marker segment including first two bytes and length
//        - 2 for standalone markers
//        - 4+length for markers with data
//
// `on_segment` function should return one of the following:
//  - `false`        - segment is removed from the output
//  - Uint8Array     - segment is replaced with the new data
//  - [ Uint8Array ] - segment is replaced with the new data
//  - anything else  - segment is copied to the output as is
//
// Any data after `EOI` (0xFFD9) marker is removed.
//
module.exports.jpeg_segments_filter = function (jpeg_bin, on_segment) {
  if (!is_uint8array(jpeg_bin)) {
    throw error('Invalid argument (jpeg_bin), Uint8Array expected', 'EINVAL');
  }

  if (typeof on_segment !== 'function') {
    throw error('Invalid argument (on_segment), Function expected', 'EINVAL');
  }

  var ranges = [];
  var out_length = 0;

  module.exports.jpeg_segments_each(jpeg_bin, function (segment) {
    var new_segment = on_segment(segment);

    if (is_uint8array(new_segment)) {
      ranges.push({ data: new_segment });
      out_length += new_segment.length;
    } else if (Array.isArray(new_segment)) {
      new_segment.filter(is_uint8array).forEach(function (s) {
        ranges.push({ data: s });
        out_length += s.length;
      });
    } else if (new_segment !== false) {
      var new_range = { start: segment.offset, end: segment.offset + segment.length };

      if (ranges.length > 0 && ranges[ranges.length - 1].end === new_range.start) {
        ranges[ranges.length - 1].end = new_range.end;
      } else {
        ranges.push(new_range);
      }

      out_length += segment.length;
    }
  });

  var result = new Uint8Array(out_length);
  var offset = 0;

  ranges.forEach(function (range) {
    var data = range.data || jpeg_bin.subarray(range.start, range.end);
    result.set(data, offset);
    offset += data.length;
  });

  return result;
};


// Call an iterator on each Exif entry in the given JPEG image
//
// Input:
//  - jpeg_bin: Uint8Array - jpeg file
//  - on_entry: Function - callback executed on each Exif entry
//    - entry:  Object
//      - is_big_endian:  Boolean - whether Exif uses big or little endian byte alignment
//      - ifd:            Number  - IFD identifier (0 for IFD0, 1 for IFD1, 0x8769 for SubIFD,
//                                 0x8825 for GPS Info, 0xA005 for Interop IFD)
//      - tag:            Number  - exif entry tag (0x0110 - camera name, 0x0112 - orientation, etc. - see Exif spec)
//      - format:         Number  - exif entry format (1 - byte, 2 - ascii, 3 - short, etc. - see Exif spec)
//      - count:          Number  - number of components of the given format inside data
//                                 (usually 1, or string length for ascii format)
//      - entry_offset:   Number  - start of Exif entry (entry length is always 12, so not included)
//      - data_offset:    Number  - start of data attached to Exif entry (will overlap with entry if length <= 4)
//      - data_length:    Number  - length of data attached to Exif entry
//      - value:          Array|String|Null - our best attempt at parsing data (not all formats supported right now)
//      - is_subifd_link: Boolean - whether this entry is recognized to be a link to subifd (can't filter these out)
//
// Iteration stops early if iterator returns `false`.
//
// If Exif wasn't found anywhere (before start of the image data, SOS),
// iterator is never executed.
//
module.exports.jpeg_exif_tags_each = function (jpeg_bin, on_exif_entry) {
  if (!is_uint8array(jpeg_bin)) {
    throw error('Invalid argument (jpeg_bin), Uint8Array expected', 'EINVAL');
  }

  if (typeof on_exif_entry !== 'function') {
    throw error('Invalid argument (on_exif_entry), Function expected', 'EINVAL');
  }

  /* eslint-disable consistent-return */
  module.exports.jpeg_segments_each(jpeg_bin, function (segment) {
    if (segment.code === 0xDA /* SOS */) return false;

    // look for APP1 segment and compare header with 'Exif\0\0'
    if (segment.code === 0xE1 && segment.length >= 10 &&
        jpeg_bin[segment.offset + 4] === 0x45 && jpeg_bin[segment.offset + 5] === 0x78 &&
        jpeg_bin[segment.offset + 6] === 0x69 && jpeg_bin[segment.offset + 7] === 0x66 &&
        jpeg_bin[segment.offset + 8] === 0x00 && jpeg_bin[segment.offset + 9] === 0x00) {

      new ExifParser(jpeg_bin, segment.offset + 10, segment.offset + segment.length).each(on_exif_entry);
      return false;
    }
  });
};


// Remove Exif entries in the given JPEG image
//
// Input:
//  - jpeg_bin: Uint8Array - jpeg file
//  - on_entry: Function - callback executed on each Exif entry
//    - entry:  Object
//      - is_big_endian:  Boolean - whether Exif uses big or little endian byte alignment
//      - ifd:            Number  - IFD identifier (0 for IFD0, 1 for IFD1, 0x8769 for SubIFD,
//                                  0x8825 for GPS Info, 0xA005 for Interop IFD)
//      - tag:            Number  - exif entry tag (0x0110 - camera name, 0x0112 - orientation, etc. - see Exif spec)
//      - format:         Number  - exif entry format (1 - byte, 2 - ascii, 3 - short, etc. - see Exif spec)
//      - count:          Number  - number of components of the given format inside data
//                                  (usually 1, or string length for ascii format)
//      - entry_offset:   Number  - start of Exif entry (entry length is always 12, so not included)
//      - data_offset:    Number  - start of data attached to Exif entry (will overlap with entry if length <= 4)
//      - data_length:    Number  - length of data attached to Exif entry
//      - value:          Array|String|Null - our best attempt at parsing data (not all formats supported right now)
//      - is_subifd_link: Boolean - whether this entry is recognized to be a link to subifd (can't filter these out)
//
// This function removes following from Exif:
//  - all entries where iterator returned false (except subifd links which are mandatory)
//  - IFD1 and thumbnail image (the purpose of this function is to reduce file size,
//    so thumbnail is usually the first thing to go)
//  - all other data that isn't in IFD0, SubIFD, GPSIFD, InteropIFD
//    (theoretically possible proprietary extensions, I haven't seen any of these yet)
//
// Changing data inside Exif entries is NOT supported yet (modifying `entry` object inside callback may break stuff).
//
// If Exif wasn't found anywhere (before start of the image data, SOS),
// iterator is never executed, and original JPEG is returned as is.
//
module.exports.jpeg_exif_tags_filter = function (jpeg_bin, on_exif_entry) {
  if (!is_uint8array(jpeg_bin)) {
    throw error('Invalid argument (jpeg_bin), Uint8Array expected', 'EINVAL');
  }

  if (typeof on_exif_entry !== 'function') {
    throw error('Invalid argument (on_exif_entry), Function expected', 'EINVAL');
  }

  var stop_search = false;

  return module.exports.jpeg_segments_filter(jpeg_bin, function (segment) {
    if (stop_search) return;
    if (segment.code === 0xDA /* SOS */) stop_search = true;

    // look for APP1 segment and compare header with 'Exif\0\0'
    if (segment.code === 0xE1 && segment.length >= 10 &&
        jpeg_bin[segment.offset + 4] === 0x45 && jpeg_bin[segment.offset + 5] === 0x78 &&
        jpeg_bin[segment.offset + 6] === 0x69 && jpeg_bin[segment.offset + 7] === 0x66 &&
        jpeg_bin[segment.offset + 8] === 0x00 && jpeg_bin[segment.offset + 9] === 0x00) {

      var new_exif = new ExifParser(jpeg_bin, segment.offset + 10, segment.offset + segment.length)
        .filter(on_exif_entry);
      if (!new_exif) return false;

      var header = new Uint8Array(10);

      header.set(jpeg_bin.slice(segment.offset, segment.offset + 10));
      header[2] = ((new_exif.length + 8) >>> 8) & 0xFF;
      header[3] = (new_exif.length + 8) & 0xFF;

      stop_search = true;
      return [ header, new_exif ];
    }
  });
};


// Inserts a custom comment marker segment into JPEG file.
//
// Input:
//  - jpeg_bin: Uint8Array - jpeg file
//  - comment:  String
//
// Comment is inserted after first two bytes (FFD8, SOI).
//
// If JFIF (APP0) marker exists immediately after SOI (as mandated by the JFIF
// spec), we insert comment after it instead.
//
module.exports.jpeg_add_comment = function (jpeg_bin, comment) {
  var comment_inserted = false, segment_count = 0;

  return module.exports.jpeg_segments_filter(jpeg_bin, function (segment) {
    segment_count++;
    if (segment_count === 1 && segment.code === 0xD8 /* SOI  */) return;
    if (segment_count === 2 && segment.code === 0xE0 /* APP0 */) return;

    if (comment_inserted) return;
    comment = utf8_encode(comment);

    // comment segment
    var csegment = new Uint8Array(5 + comment.length);
    var offset = 0;

    csegment[offset++] = 0xFF;
    csegment[offset++] = 0xFE;
    csegment[offset++] = ((comment.length + 3) >>> 8) & 0xFF;
    csegment[offset++] = (comment.length + 3) & 0xFF;

    comment.split('').forEach(function (c) {
      csegment[offset++] = c.charCodeAt(0) & 0xFF;
    });

    csegment[offset++] = 0;
    comment_inserted = true;

    return [ csegment, jpeg_bin.subarray(segment.offset, segment.offset + segment.length) ];
  });
};
});

function jpeg_patch_exif(env) {
  return this._getUint8Array(env.blob).then(function (data) {
    env.is_jpeg = image_traverse.is_jpeg(data);

    if (!env.is_jpeg) return Promise.resolve(env);

    env.orig_blob = env.blob;

    try {
      var exif_is_big_endian, orientation_offset;

      /* eslint-disable consistent-return */
      image_traverse.jpeg_exif_tags_each(data, function (entry) {
        if (entry.ifd === 0 && entry.tag === 0x112 && Array.isArray(entry.value)) {
          env.orientation    = entry.value[0] || 1;
          exif_is_big_endian = entry.is_big_endian;
          orientation_offset = entry.data_offset;
          return false;
        }
      });

      if (orientation_offset) {
        var orientation_patch = exif_is_big_endian ?
          new Uint8Array([ 0, 1 ]) :
          new Uint8Array([ 1, 0 ]);

        env.blob = new Blob([
          data.slice(0, orientation_offset),
          orientation_patch,
          data.slice(orientation_offset + 2)
        ], { type: 'image/jpeg' });
      }
    } catch (_) {}

    return env;
  });
}


function jpeg_rotate_canvas(env) {
  if (!env.is_jpeg) return Promise.resolve(env);

  var orientation = env.orientation - 1;
  if (!orientation) return Promise.resolve(env);

  var canvas;

  if (orientation & 4) {
    canvas = this.pica.options.createCanvas(env.out_canvas.height, env.out_canvas.width);
  } else {
    canvas = this.pica.options.createCanvas(env.out_canvas.width, env.out_canvas.height);
  }

  var ctx = canvas.getContext('2d');

  ctx.save();

  if (orientation & 1) ctx.transform(-1, 0, 0, 1, canvas.width, 0);
  if (orientation & 2) ctx.transform(-1, 0, 0, -1, canvas.width, canvas.height);
  if (orientation & 4) ctx.transform(0, 1, 1, 0, 0, 0);

  ctx.drawImage(env.out_canvas, 0, 0);
  ctx.restore();

  // Safari 12 workaround
  // https://github.com/nodeca/pica/issues/199
  env.out_canvas.width = env.out_canvas.height = 0;

  env.out_canvas = canvas;

  return Promise.resolve(env);
}


function jpeg_attach_orig_segments(env) {
  if (!env.is_jpeg) return Promise.resolve(env);

  return Promise.all([
    this._getUint8Array(env.blob),
    this._getUint8Array(env.out_blob)
  ]).then(function (res) {
    var data = res[0];
    var data_out = res[1];

    if (!image_traverse.is_jpeg(data)) return Promise.resolve(env);

    var segments = [];

    image_traverse.jpeg_segments_each(data, function (segment) {
      if (segment.code === 0xDA /* SOS */) return false;
      segments.push(segment);
    });

    segments = segments
      .filter(function (segment) {
        // Drop ICC_PROFILE
        //
        if (segment.code === 0xE2) return false;

        // Keep all APPn segments excluding APP2 (ICC_PROFILE),
        // remove others because most of them depend on image data (DCT and such).
        //
        // APP0 - JFIF, APP1 - Exif, the rest are photoshop metadata and such
        //
        // See full list at https://www.w3.org/Graphics/JPEG/itu-t81.pdf (table B.1 on page 32)
        //
        if (segment.code >= 0xE0 && segment.code < 0xF0) return true;

        // Keep comments
        //
        if (segment.code === 0xFE) return true;

        return false;
      })
      .map(function (segment) {
        return data.slice(segment.offset, segment.offset + segment.length);
      });

    env.out_blob = new Blob(
      // intentionally omitting expected JFIF segment (offset 2 to 20)
      [ data_out.slice(0, 2) ].concat(segments).concat([ data_out.slice(20) ]),
      { type: 'image/jpeg' }
    );

    return env;
  });
}


function assign(reducer) {
  reducer.before('_blob_to_image', jpeg_patch_exif);
  reducer.after('_transform',      jpeg_rotate_canvas);
  reducer.after('_create_blob',    jpeg_attach_orig_segments);
}


var jpeg_patch_exif_1 = jpeg_patch_exif;
var jpeg_rotate_canvas_1 = jpeg_rotate_canvas;
var jpeg_attach_orig_segments_1 = jpeg_attach_orig_segments;
var assign_1 = assign;

var jpeg_plugins = {
	jpeg_patch_exif: jpeg_patch_exif_1,
	jpeg_rotate_canvas: jpeg_rotate_canvas_1,
	jpeg_attach_orig_segments: jpeg_attach_orig_segments_1,
	assign: assign_1
};

function ImageBlobReduce(options) {
  if (!(this instanceof ImageBlobReduce)) return new ImageBlobReduce(options);

  options = options || {};

  this.pica = options.pica || pica({});
  this.initialized = false;

  this.utils = utils;
}


ImageBlobReduce.prototype.use = function (plugin /*, params, ... */) {
  var args = [ this ].concat(Array.prototype.slice.call(arguments, 1));
  plugin.apply(plugin, args);
  return this;
};


ImageBlobReduce.prototype.init = function () {
  this.use(jpeg_plugins.assign);
};


ImageBlobReduce.prototype.toBlob = function (blob, options) {
  var opts = utils.assign({ max: Infinity }, options);
  var env = {
    blob: blob,
    opts: opts
  };

  if (!this.initialized) {
    this.init();
    this.initialized = true;
  }

  return Promise.resolve(env)
    .then(this._blob_to_image)
    .then(this._calculate_size)
    .then(this._transform)
    .then(this._cleanup)
    .then(this._create_blob)
    .then(function (_env) {
      // Safari 12 workaround
      // https://github.com/nodeca/pica/issues/199
      _env.out_canvas.width = _env.out_canvas.height = 0;

      return _env.out_blob;
    });
};


ImageBlobReduce.prototype.toCanvas = function (blob, options) {
  var opts = utils.assign({ max: Infinity }, options);
  var env = {
    blob: blob,
    opts: opts
  };

  if (!this.initialized) {
    this.init();
    this.initialized = true;
  }

  return Promise.resolve(env)
    .then(this._blob_to_image)
    .then(this._calculate_size)
    .then(this._transform)
    .then(this._cleanup)
    .then(function (_env) { return _env.out_canvas; });
};


ImageBlobReduce.prototype.before = function (method_name, fn) {
  if (!this[method_name]) throw new Error('Method "' + method_name + '" does not exist');
  if (typeof fn !== 'function') throw new Error('Invalid argument "fn", function expected');

  var old_fn = this[method_name];
  var self = this;

  this[method_name] = function (env) {
    return fn.call(self, env).then(function (_env) {
      return old_fn.call(self, _env);
    });
  };

  return this;
};


ImageBlobReduce.prototype.after = function (method_name, fn) {
  if (!this[method_name]) throw new Error('Method "' + method_name + '" does not exist');
  if (typeof fn !== 'function') throw new Error('Invalid argument "fn", function expected');

  var old_fn = this[method_name];
  var self = this;

  this[method_name] = function (env) {
    return old_fn.call(self, env).then(function (_env) {
      return fn.call(self, _env);
    });
  };

  return this;
};


ImageBlobReduce.prototype._blob_to_image = function (env) {
  var URL = window.URL || window.webkitURL || window.mozURL || window.msURL;

  env.image = document.createElement('img');
  env.image_url = URL.createObjectURL(env.blob);
  env.image.src = env.image_url;

  return new Promise(function (resolve, reject) {
    env.image.onerror = function () { reject(new Error('ImageBlobReduce: failed to create Image() from blob')); };
    env.image.onload = function () { resolve(env); };
  });
};


ImageBlobReduce.prototype._calculate_size = function (env) {
  //
  // Note, if your need not "symmetric" resize logic, you MUST check
  // `env.orientation` (set by plugins) and swap width/height appropriately.
  //
  var scale_factor = env.opts.max / Math.max(env.image.width, env.image.height);

  if (scale_factor > 1) scale_factor = 1;

  env.transform_width = Math.max(Math.round(env.image.width * scale_factor), 1);
  env.transform_height = Math.max(Math.round(env.image.height * scale_factor), 1);

  // Info for user plugins, to check if scaling applied
  env.scale_factor = scale_factor;

  return Promise.resolve(env);
};


ImageBlobReduce.prototype._transform = function (env) {
  env.out_canvas = this.pica.options.createCanvas(env.transform_width, env.transform_height);

  // Dim env temporary vars to prohibit use and avoid confusion when orientation
  // changed. You should take real size from canvas.
  env.transform_width = null;
  env.transform_height = null;

  // By default use alpha for png only
  var pica_opts = { alpha: env.blob.type === 'image/png' };

  // Extract pica options if been passed
  this.utils.assign(pica_opts, this.utils.pick_pica_resize_options(env.opts));

  return this.pica
    .resize(env.image, env.out_canvas, pica_opts)
    .then(function () { return env; });
};


ImageBlobReduce.prototype._cleanup = function (env) {
  env.image.src = '';
  env.image = null;

  var URL = window.URL || window.webkitURL || window.mozURL || window.msURL;
  if (URL.revokeObjectURL) URL.revokeObjectURL(env.image_url);

  env.image_url = null;

  return Promise.resolve(env);
};


ImageBlobReduce.prototype._create_blob = function (env) {
  return this.pica.toBlob(env.out_canvas, env.blob.type)
    .then(function (blob) {
      env.out_blob = blob;
      return env;
    });
};


ImageBlobReduce.prototype._getUint8Array = function (blob) {
  if (blob.arrayBuffer) {
    return blob.arrayBuffer().then(function (buf) {
      return new Uint8Array(buf);
    });
  }

  return new Promise(function (resolve, reject) {
    var fr = new FileReader();

    fr.readAsArrayBuffer(blob);

    fr.onload = function () { resolve(new Uint8Array(fr.result)); };
    fr.onerror = function () {
      reject(new Error('ImageBlobReduce: failed to load data from input blob'));
      fr.abort();
    };
    fr.onabort = function () {
      reject(new Error('ImageBlobReduce: failed to load data from input blob (aborted)'));
    };
  });
};


ImageBlobReduce.pica = pica;

var imageBlobReduce = ImageBlobReduce;

export default imageBlobReduce;