pngjs/browser.js

PNG encoder/decoder in pure JS, supporting any bit size & interlace, async & sync with full test suite.

(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.png = f()}})(function(){var define,module,exports;return (function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof require&&require;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 require&&require,i=0;i<t.length;i++)o(t[i]);return o}return r})()({1:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

let interlaceUtils = require("./interlace");

let pixelBppMapper = [
  // 0 - dummy entry
  function () {},

  // 1 - L
  // 0: 0, 1: 0, 2: 0, 3: 0xff
  function (pxData, data, pxPos, rawPos) {
    if (rawPos === data.length) {
      throw new Error("Ran out of data");
    }

    let pixel = data[rawPos];
    pxData[pxPos] = pixel;
    pxData[pxPos + 1] = pixel;
    pxData[pxPos + 2] = pixel;
    pxData[pxPos + 3] = 0xff;
  },

  // 2 - LA
  // 0: 0, 1: 0, 2: 0, 3: 1
  function (pxData, data, pxPos, rawPos) {
    if (rawPos + 1 >= data.length) {
      throw new Error("Ran out of data");
    }

    let pixel = data[rawPos];
    pxData[pxPos] = pixel;
    pxData[pxPos + 1] = pixel;
    pxData[pxPos + 2] = pixel;
    pxData[pxPos + 3] = data[rawPos + 1];
  },

  // 3 - RGB
  // 0: 0, 1: 1, 2: 2, 3: 0xff
  function (pxData, data, pxPos, rawPos) {
    if (rawPos + 2 >= data.length) {
      throw new Error("Ran out of data");
    }

    pxData[pxPos] = data[rawPos];
    pxData[pxPos + 1] = data[rawPos + 1];
    pxData[pxPos + 2] = data[rawPos + 2];
    pxData[pxPos + 3] = 0xff;
  },

  // 4 - RGBA
  // 0: 0, 1: 1, 2: 2, 3: 3
  function (pxData, data, pxPos, rawPos) {
    if (rawPos + 3 >= data.length) {
      throw new Error("Ran out of data");
    }

    pxData[pxPos] = data[rawPos];
    pxData[pxPos + 1] = data[rawPos + 1];
    pxData[pxPos + 2] = data[rawPos + 2];
    pxData[pxPos + 3] = data[rawPos + 3];
  },
];

let pixelBppCustomMapper = [
  // 0 - dummy entry
  function () {},

  // 1 - L
  // 0: 0, 1: 0, 2: 0, 3: 0xff
  function (pxData, pixelData, pxPos, maxBit) {
    let pixel = pixelData[0];
    pxData[pxPos] = pixel;
    pxData[pxPos + 1] = pixel;
    pxData[pxPos + 2] = pixel;
    pxData[pxPos + 3] = maxBit;
  },

  // 2 - LA
  // 0: 0, 1: 0, 2: 0, 3: 1
  function (pxData, pixelData, pxPos) {
    let pixel = pixelData[0];
    pxData[pxPos] = pixel;
    pxData[pxPos + 1] = pixel;
    pxData[pxPos + 2] = pixel;
    pxData[pxPos + 3] = pixelData[1];
  },

  // 3 - RGB
  // 0: 0, 1: 1, 2: 2, 3: 0xff
  function (pxData, pixelData, pxPos, maxBit) {
    pxData[pxPos] = pixelData[0];
    pxData[pxPos + 1] = pixelData[1];
    pxData[pxPos + 2] = pixelData[2];
    pxData[pxPos + 3] = maxBit;
  },

  // 4 - RGBA
  // 0: 0, 1: 1, 2: 2, 3: 3
  function (pxData, pixelData, pxPos) {
    pxData[pxPos] = pixelData[0];
    pxData[pxPos + 1] = pixelData[1];
    pxData[pxPos + 2] = pixelData[2];
    pxData[pxPos + 3] = pixelData[3];
  },
];

function bitRetriever(data, depth) {
  let leftOver = [];
  let i = 0;

  function split() {
    if (i === data.length) {
      throw new Error("Ran out of data");
    }
    let byte = data[i];
    i++;
    let byte8, byte7, byte6, byte5, byte4, byte3, byte2, byte1;
    switch (depth) {
      default:
        throw new Error("unrecognised depth");
      case 16:
        byte2 = data[i];
        i++;
        leftOver.push((byte << 8) + byte2);
        break;
      case 4:
        byte2 = byte & 0x0f;
        byte1 = byte >> 4;
        leftOver.push(byte1, byte2);
        break;
      case 2:
        byte4 = byte & 3;
        byte3 = (byte >> 2) & 3;
        byte2 = (byte >> 4) & 3;
        byte1 = (byte >> 6) & 3;
        leftOver.push(byte1, byte2, byte3, byte4);
        break;
      case 1:
        byte8 = byte & 1;
        byte7 = (byte >> 1) & 1;
        byte6 = (byte >> 2) & 1;
        byte5 = (byte >> 3) & 1;
        byte4 = (byte >> 4) & 1;
        byte3 = (byte >> 5) & 1;
        byte2 = (byte >> 6) & 1;
        byte1 = (byte >> 7) & 1;
        leftOver.push(byte1, byte2, byte3, byte4, byte5, byte6, byte7, byte8);
        break;
    }
  }

  return {
    get: function (count) {
      while (leftOver.length < count) {
        split();
      }
      let returner = leftOver.slice(0, count);
      leftOver = leftOver.slice(count);
      return returner;
    },
    resetAfterLine: function () {
      leftOver.length = 0;
    },
    end: function () {
      if (i !== data.length) {
        throw new Error("extra data found");
      }
    },
  };
}

function mapImage8Bit(image, pxData, getPxPos, bpp, data, rawPos) {
  // eslint-disable-line max-params
  let imageWidth = image.width;
  let imageHeight = image.height;
  let imagePass = image.index;
  for (let y = 0; y < imageHeight; y++) {
    for (let x = 0; x < imageWidth; x++) {
      let pxPos = getPxPos(x, y, imagePass);
      pixelBppMapper[bpp](pxData, data, pxPos, rawPos);
      rawPos += bpp; //eslint-disable-line no-param-reassign
    }
  }
  return rawPos;
}

function mapImageCustomBit(image, pxData, getPxPos, bpp, bits, maxBit) {
  // eslint-disable-line max-params
  let imageWidth = image.width;
  let imageHeight = image.height;
  let imagePass = image.index;
  for (let y = 0; y < imageHeight; y++) {
    for (let x = 0; x < imageWidth; x++) {
      let pixelData = bits.get(bpp);
      let pxPos = getPxPos(x, y, imagePass);
      pixelBppCustomMapper[bpp](pxData, pixelData, pxPos, maxBit);
    }
    bits.resetAfterLine();
  }
}

exports.dataToBitMap = function (data, bitmapInfo) {
  let width = bitmapInfo.width;
  let height = bitmapInfo.height;
  let depth = bitmapInfo.depth;
  let bpp = bitmapInfo.bpp;
  let interlace = bitmapInfo.interlace;
  let bits;

  if (depth !== 8) {
    bits = bitRetriever(data, depth);
  }
  let pxData;
  if (depth <= 8) {
    pxData = Buffer.alloc(width * height * 4);
  } else {
    pxData = new Uint16Array(width * height * 4);
  }
  let maxBit = Math.pow(2, depth) - 1;
  let rawPos = 0;
  let images;
  let getPxPos;

  if (interlace) {
    images = interlaceUtils.getImagePasses(width, height);
    getPxPos = interlaceUtils.getInterlaceIterator(width, height);
  } else {
    let nonInterlacedPxPos = 0;
    getPxPos = function () {
      let returner = nonInterlacedPxPos;
      nonInterlacedPxPos += 4;
      return returner;
    };
    images = [{ width: width, height: height }];
  }

  for (let imageIndex = 0; imageIndex < images.length; imageIndex++) {
    if (depth === 8) {
      rawPos = mapImage8Bit(
        images[imageIndex],
        pxData,
        getPxPos,
        bpp,
        data,
        rawPos
      );
    } else {
      mapImageCustomBit(
        images[imageIndex],
        pxData,
        getPxPos,
        bpp,
        bits,
        maxBit
      );
    }
  }
  if (depth === 8) {
    if (rawPos !== data.length) {
      throw new Error("extra data found");
    }
  } else {
    bits.end();
  }

  return pxData;
};

}).call(this)}).call(this,require("buffer").Buffer)
},{"./interlace":11,"buffer":32}],2:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

let constants = require("./constants");

module.exports = function (dataIn, width, height, options) {
  let outHasAlpha =
    [constants.COLORTYPE_COLOR_ALPHA, constants.COLORTYPE_ALPHA].indexOf(
      options.colorType
    ) !== -1;
  if (options.colorType === options.inputColorType) {
    let bigEndian = (function () {
      let buffer = new ArrayBuffer(2);
      new DataView(buffer).setInt16(0, 256, true /* littleEndian */);
      // Int16Array uses the platform's endianness.
      return new Int16Array(buffer)[0] !== 256;
    })();
    // If no need to convert to grayscale and alpha is present/absent in both, take a fast route
    if (options.bitDepth === 8 || (options.bitDepth === 16 && bigEndian)) {
      return dataIn;
    }
  }

  // map to a UInt16 array if data is 16bit, fix endianness below
  let data = options.bitDepth !== 16 ? dataIn : new Uint16Array(dataIn.buffer);

  let maxValue = 255;
  let inBpp = constants.COLORTYPE_TO_BPP_MAP[options.inputColorType];
  if (inBpp === 4 && !options.inputHasAlpha) {
    inBpp = 3;
  }
  let outBpp = constants.COLORTYPE_TO_BPP_MAP[options.colorType];
  if (options.bitDepth === 16) {
    maxValue = 65535;
    outBpp *= 2;
  }
  let outData = Buffer.alloc(width * height * outBpp);

  let inIndex = 0;
  let outIndex = 0;

  let bgColor = options.bgColor || {};
  if (bgColor.red === undefined) {
    bgColor.red = maxValue;
  }
  if (bgColor.green === undefined) {
    bgColor.green = maxValue;
  }
  if (bgColor.blue === undefined) {
    bgColor.blue = maxValue;
  }

  function getRGBA() {
    let red;
    let green;
    let blue;
    let alpha = maxValue;
    switch (options.inputColorType) {
      case constants.COLORTYPE_COLOR_ALPHA:
        alpha = data[inIndex + 3];
        red = data[inIndex];
        green = data[inIndex + 1];
        blue = data[inIndex + 2];
        break;
      case constants.COLORTYPE_COLOR:
        red = data[inIndex];
        green = data[inIndex + 1];
        blue = data[inIndex + 2];
        break;
      case constants.COLORTYPE_ALPHA:
        alpha = data[inIndex + 1];
        red = data[inIndex];
        green = red;
        blue = red;
        break;
      case constants.COLORTYPE_GRAYSCALE:
        red = data[inIndex];
        green = red;
        blue = red;
        break;
      default:
        throw new Error(
          "input color type:" +
            options.inputColorType +
            " is not supported at present"
        );
    }

    if (options.inputHasAlpha) {
      if (!outHasAlpha) {
        alpha /= maxValue;
        red = Math.min(
          Math.max(Math.round((1 - alpha) * bgColor.red + alpha * red), 0),
          maxValue
        );
        green = Math.min(
          Math.max(Math.round((1 - alpha) * bgColor.green + alpha * green), 0),
          maxValue
        );
        blue = Math.min(
          Math.max(Math.round((1 - alpha) * bgColor.blue + alpha * blue), 0),
          maxValue
        );
      }
    }
    return { red: red, green: green, blue: blue, alpha: alpha };
  }

  for (let y = 0; y < height; y++) {
    for (let x = 0; x < width; x++) {
      let rgba = getRGBA(data, inIndex);

      switch (options.colorType) {
        case constants.COLORTYPE_COLOR_ALPHA:
        case constants.COLORTYPE_COLOR:
          if (options.bitDepth === 8) {
            outData[outIndex] = rgba.red;
            outData[outIndex + 1] = rgba.green;
            outData[outIndex + 2] = rgba.blue;
            if (outHasAlpha) {
              outData[outIndex + 3] = rgba.alpha;
            }
          } else {
            outData.writeUInt16BE(rgba.red, outIndex);
            outData.writeUInt16BE(rgba.green, outIndex + 2);
            outData.writeUInt16BE(rgba.blue, outIndex + 4);
            if (outHasAlpha) {
              outData.writeUInt16BE(rgba.alpha, outIndex + 6);
            }
          }
          break;
        case constants.COLORTYPE_ALPHA:
        case constants.COLORTYPE_GRAYSCALE: {
          // Convert to grayscale and alpha
          let grayscale = (rgba.red + rgba.green + rgba.blue) / 3;
          if (options.bitDepth === 8) {
            outData[outIndex] = grayscale;
            if (outHasAlpha) {
              outData[outIndex + 1] = rgba.alpha;
            }
          } else {
            outData.writeUInt16BE(grayscale, outIndex);
            if (outHasAlpha) {
              outData.writeUInt16BE(rgba.alpha, outIndex + 2);
            }
          }
          break;
        }
        default:
          throw new Error("unrecognised color Type " + options.colorType);
      }

      inIndex += inBpp;
      outIndex += outBpp;
    }
  }

  return outData;
};

}).call(this)}).call(this,require("buffer").Buffer)
},{"./constants":4,"buffer":32}],3:[function(require,module,exports){
(function (process,Buffer){(function (){
"use strict";

let util = require("util");
let Stream = require("stream");

let ChunkStream = (module.exports = function () {
  Stream.call(this);

  this._buffers = [];
  this._buffered = 0;

  this._reads = [];
  this._paused = false;

  this._encoding = "utf8";
  this.writable = true;
});
util.inherits(ChunkStream, Stream);

ChunkStream.prototype.read = function (length, callback) {
  this._reads.push({
    length: Math.abs(length), // if length < 0 then at most this length
    allowLess: length < 0,
    func: callback,
  });

  process.nextTick(
    function () {
      this._process();

      // its paused and there is not enought data then ask for more
      if (this._paused && this._reads && this._reads.length > 0) {
        this._paused = false;

        this.emit("drain");
      }
    }.bind(this)
  );
};

ChunkStream.prototype.write = function (data, encoding) {
  if (!this.writable) {
    this.emit("error", new Error("Stream not writable"));
    return false;
  }

  let dataBuffer;
  if (Buffer.isBuffer(data)) {
    dataBuffer = data;
  } else {
    dataBuffer = Buffer.from(data, encoding || this._encoding);
  }

  this._buffers.push(dataBuffer);
  this._buffered += dataBuffer.length;

  this._process();

  // ok if there are no more read requests
  if (this._reads && this._reads.length === 0) {
    this._paused = true;
  }

  return this.writable && !this._paused;
};

ChunkStream.prototype.end = function (data, encoding) {
  if (data) {
    this.write(data, encoding);
  }

  this.writable = false;

  // already destroyed
  if (!this._buffers) {
    return;
  }

  // enqueue or handle end
  if (this._buffers.length === 0) {
    this._end();
  } else {
    this._buffers.push(null);
    this._process();
  }
};

ChunkStream.prototype.destroySoon = ChunkStream.prototype.end;

ChunkStream.prototype._end = function () {
  if (this._reads.length > 0) {
    this.emit("error", new Error("Unexpected end of input"));
  }

  this.destroy();
};

ChunkStream.prototype.destroy = function () {
  if (!this._buffers) {
    return;
  }

  this.writable = false;
  this._reads = null;
  this._buffers = null;

  this.emit("close");
};

ChunkStream.prototype._processReadAllowingLess = function (read) {
  // ok there is any data so that we can satisfy this request
  this._reads.shift(); // == read

  // first we need to peek into first buffer
  let smallerBuf = this._buffers[0];

  // ok there is more data than we need
  if (smallerBuf.length > read.length) {
    this._buffered -= read.length;
    this._buffers[0] = smallerBuf.slice(read.length);

    read.func.call(this, smallerBuf.slice(0, read.length));
  } else {
    // ok this is less than maximum length so use it all
    this._buffered -= smallerBuf.length;
    this._buffers.shift(); // == smallerBuf

    read.func.call(this, smallerBuf);
  }
};

ChunkStream.prototype._processRead = function (read) {
  this._reads.shift(); // == read

  let pos = 0;
  let count = 0;
  let data = Buffer.alloc(read.length);

  // create buffer for all data
  while (pos < read.length) {
    let buf = this._buffers[count++];
    let len = Math.min(buf.length, read.length - pos);

    buf.copy(data, pos, 0, len);
    pos += len;

    // last buffer wasn't used all so just slice it and leave
    if (len !== buf.length) {
      this._buffers[--count] = buf.slice(len);
    }
  }

  // remove all used buffers
  if (count > 0) {
    this._buffers.splice(0, count);
  }

  this._buffered -= read.length;

  read.func.call(this, data);
};

ChunkStream.prototype._process = function () {
  try {
    // as long as there is any data and read requests
    while (this._buffered > 0 && this._reads && this._reads.length > 0) {
      let read = this._reads[0];

      // read any data (but no more than length)
      if (read.allowLess) {
        this._processReadAllowingLess(read);
      } else if (this._buffered >= read.length) {
        // ok we can meet some expectations

        this._processRead(read);
      } else {
        // not enought data to satisfy first request in queue
        // so we need to wait for more
        break;
      }
    }

    if (this._buffers && !this.writable) {
      this._end();
    }
  } catch (ex) {
    this.emit("error", ex);
  }
};

}).call(this)}).call(this,require('_process'),require("buffer").Buffer)
},{"_process":63,"buffer":32,"stream":65,"util":84}],4:[function(require,module,exports){
"use strict";

module.exports = {
  PNG_SIGNATURE: [0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a],

  TYPE_IHDR: 0x49484452,
  TYPE_IEND: 0x49454e44,
  TYPE_IDAT: 0x49444154,
  TYPE_PLTE: 0x504c5445,
  TYPE_tRNS: 0x74524e53, // eslint-disable-line camelcase
  TYPE_gAMA: 0x67414d41, // eslint-disable-line camelcase

  // color-type bits
  COLORTYPE_GRAYSCALE: 0,
  COLORTYPE_PALETTE: 1,
  COLORTYPE_COLOR: 2,
  COLORTYPE_ALPHA: 4, // e.g. grayscale and alpha

  // color-type combinations
  COLORTYPE_PALETTE_COLOR: 3,
  COLORTYPE_COLOR_ALPHA: 6,

  COLORTYPE_TO_BPP_MAP: {
    0: 1,
    2: 3,
    3: 1,
    4: 2,
    6: 4,
  },

  GAMMA_DIVISION: 100000,
};

},{}],5:[function(require,module,exports){
"use strict";

let crcTable = [];

(function () {
  for (let i = 0; i < 256; i++) {
    let currentCrc = i;
    for (let j = 0; j < 8; j++) {
      if (currentCrc & 1) {
        currentCrc = 0xedb88320 ^ (currentCrc >>> 1);
      } else {
        currentCrc = currentCrc >>> 1;
      }
    }
    crcTable[i] = currentCrc;
  }
})();

let CrcCalculator = (module.exports = function () {
  this._crc = -1;
});

CrcCalculator.prototype.write = function (data) {
  for (let i = 0; i < data.length; i++) {
    this._crc = crcTable[(this._crc ^ data[i]) & 0xff] ^ (this._crc >>> 8);
  }
  return true;
};

CrcCalculator.prototype.crc32 = function () {
  return this._crc ^ -1;
};

CrcCalculator.crc32 = function (buf) {
  let crc = -1;
  for (let i = 0; i < buf.length; i++) {
    crc = crcTable[(crc ^ buf[i]) & 0xff] ^ (crc >>> 8);
  }
  return crc ^ -1;
};

},{}],6:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

let paethPredictor = require("./paeth-predictor");

function filterNone(pxData, pxPos, byteWidth, rawData, rawPos) {
  for (let x = 0; x < byteWidth; x++) {
    rawData[rawPos + x] = pxData[pxPos + x];
  }
}

function filterSumNone(pxData, pxPos, byteWidth) {
  let sum = 0;
  let length = pxPos + byteWidth;

  for (let i = pxPos; i < length; i++) {
    sum += Math.abs(pxData[i]);
  }
  return sum;
}

function filterSub(pxData, pxPos, byteWidth, rawData, rawPos, bpp) {
  for (let x = 0; x < byteWidth; x++) {
    let left = x >= bpp ? pxData[pxPos + x - bpp] : 0;
    let val = pxData[pxPos + x] - left;

    rawData[rawPos + x] = val;
  }
}

function filterSumSub(pxData, pxPos, byteWidth, bpp) {
  let sum = 0;
  for (let x = 0; x < byteWidth; x++) {
    let left = x >= bpp ? pxData[pxPos + x - bpp] : 0;
    let val = pxData[pxPos + x] - left;

    sum += Math.abs(val);
  }

  return sum;
}

function filterUp(pxData, pxPos, byteWidth, rawData, rawPos) {
  for (let x = 0; x < byteWidth; x++) {
    let up = pxPos > 0 ? pxData[pxPos + x - byteWidth] : 0;
    let val = pxData[pxPos + x] - up;

    rawData[rawPos + x] = val;
  }
}

function filterSumUp(pxData, pxPos, byteWidth) {
  let sum = 0;
  let length = pxPos + byteWidth;
  for (let x = pxPos; x < length; x++) {
    let up = pxPos > 0 ? pxData[x - byteWidth] : 0;
    let val = pxData[x] - up;

    sum += Math.abs(val);
  }

  return sum;
}

function filterAvg(pxData, pxPos, byteWidth, rawData, rawPos, bpp) {
  for (let x = 0; x < byteWidth; x++) {
    let left = x >= bpp ? pxData[pxPos + x - bpp] : 0;
    let up = pxPos > 0 ? pxData[pxPos + x - byteWidth] : 0;
    let val = pxData[pxPos + x] - ((left + up) >> 1);

    rawData[rawPos + x] = val;
  }
}

function filterSumAvg(pxData, pxPos, byteWidth, bpp) {
  let sum = 0;
  for (let x = 0; x < byteWidth; x++) {
    let left = x >= bpp ? pxData[pxPos + x - bpp] : 0;
    let up = pxPos > 0 ? pxData[pxPos + x - byteWidth] : 0;
    let val = pxData[pxPos + x] - ((left + up) >> 1);

    sum += Math.abs(val);
  }

  return sum;
}

function filterPaeth(pxData, pxPos, byteWidth, rawData, rawPos, bpp) {
  for (let x = 0; x < byteWidth; x++) {
    let left = x >= bpp ? pxData[pxPos + x - bpp] : 0;
    let up = pxPos > 0 ? pxData[pxPos + x - byteWidth] : 0;
    let upleft =
      pxPos > 0 && x >= bpp ? pxData[pxPos + x - (byteWidth + bpp)] : 0;
    let val = pxData[pxPos + x] - paethPredictor(left, up, upleft);

    rawData[rawPos + x] = val;
  }
}

function filterSumPaeth(pxData, pxPos, byteWidth, bpp) {
  let sum = 0;
  for (let x = 0; x < byteWidth; x++) {
    let left = x >= bpp ? pxData[pxPos + x - bpp] : 0;
    let up = pxPos > 0 ? pxData[pxPos + x - byteWidth] : 0;
    let upleft =
      pxPos > 0 && x >= bpp ? pxData[pxPos + x - (byteWidth + bpp)] : 0;
    let val = pxData[pxPos + x] - paethPredictor(left, up, upleft);

    sum += Math.abs(val);
  }

  return sum;
}

let filters = {
  0: filterNone,
  1: filterSub,
  2: filterUp,
  3: filterAvg,
  4: filterPaeth,
};

let filterSums = {
  0: filterSumNone,
  1: filterSumSub,
  2: filterSumUp,
  3: filterSumAvg,
  4: filterSumPaeth,
};

module.exports = function (pxData, width, height, options, bpp) {
  let filterTypes;
  if (!("filterType" in options) || options.filterType === -1) {
    filterTypes = [0, 1, 2, 3, 4];
  } else if (typeof options.filterType === "number") {
    filterTypes = [options.filterType];
  } else {
    throw new Error("unrecognised filter types");
  }

  if (options.bitDepth === 16) {
    bpp *= 2;
  }
  let byteWidth = width * bpp;
  let rawPos = 0;
  let pxPos = 0;
  let rawData = Buffer.alloc((byteWidth + 1) * height);

  let sel = filterTypes[0];

  for (let y = 0; y < height; y++) {
    if (filterTypes.length > 1) {
      // find best filter for this line (with lowest sum of values)
      let min = Infinity;

      for (let i = 0; i < filterTypes.length; i++) {
        let sum = filterSums[filterTypes[i]](pxData, pxPos, byteWidth, bpp);
        if (sum < min) {
          sel = filterTypes[i];
          min = sum;
        }
      }
    }

    rawData[rawPos] = sel;
    rawPos++;
    filters[sel](pxData, pxPos, byteWidth, rawData, rawPos, bpp);
    rawPos += byteWidth;
    pxPos += byteWidth;
  }
  return rawData;
};

}).call(this)}).call(this,require("buffer").Buffer)
},{"./paeth-predictor":15,"buffer":32}],7:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

let util = require("util");
let ChunkStream = require("./chunkstream");
let Filter = require("./filter-parse");

let FilterAsync = (module.exports = function (bitmapInfo) {
  ChunkStream.call(this);

  let buffers = [];
  let that = this;
  this._filter = new Filter(bitmapInfo, {
    read: this.read.bind(this),
    write: function (buffer) {
      buffers.push(buffer);
    },
    complete: function () {
      that.emit("complete", Buffer.concat(buffers));
    },
  });

  this._filter.start();
});
util.inherits(FilterAsync, ChunkStream);

}).call(this)}).call(this,require("buffer").Buffer)
},{"./chunkstream":3,"./filter-parse":9,"buffer":32,"util":84}],8:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

let SyncReader = require("./sync-reader");
let Filter = require("./filter-parse");

exports.process = function (inBuffer, bitmapInfo) {
  let outBuffers = [];
  let reader = new SyncReader(inBuffer);
  let filter = new Filter(bitmapInfo, {
    read: reader.read.bind(reader),
    write: function (bufferPart) {
      outBuffers.push(bufferPart);
    },
    complete: function () {},
  });

  filter.start();
  reader.process();

  return Buffer.concat(outBuffers);
};

}).call(this)}).call(this,require("buffer").Buffer)
},{"./filter-parse":9,"./sync-reader":22,"buffer":32}],9:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

let interlaceUtils = require("./interlace");
let paethPredictor = require("./paeth-predictor");

function getByteWidth(width, bpp, depth) {
  let byteWidth = width * bpp;
  if (depth !== 8) {
    byteWidth = Math.ceil(byteWidth / (8 / depth));
  }
  return byteWidth;
}

let Filter = (module.exports = function (bitmapInfo, dependencies) {
  let width = bitmapInfo.width;
  let height = bitmapInfo.height;
  let interlace = bitmapInfo.interlace;
  let bpp = bitmapInfo.bpp;
  let depth = bitmapInfo.depth;

  this.read = dependencies.read;
  this.write = dependencies.write;
  this.complete = dependencies.complete;

  this._imageIndex = 0;
  this._images = [];
  if (interlace) {
    let passes = interlaceUtils.getImagePasses(width, height);
    for (let i = 0; i < passes.length; i++) {
      this._images.push({
        byteWidth: getByteWidth(passes[i].width, bpp, depth),
        height: passes[i].height,
        lineIndex: 0,
      });
    }
  } else {
    this._images.push({
      byteWidth: getByteWidth(width, bpp, depth),
      height: height,
      lineIndex: 0,
    });
  }

  // when filtering the line we look at the pixel to the left
  // the spec also says it is done on a byte level regardless of the number of pixels
  // so if the depth is byte compatible (8 or 16) we subtract the bpp in order to compare back
  // a pixel rather than just a different byte part. However if we are sub byte, we ignore.
  if (depth === 8) {
    this._xComparison = bpp;
  } else if (depth === 16) {
    this._xComparison = bpp * 2;
  } else {
    this._xComparison = 1;
  }
});

Filter.prototype.start = function () {
  this.read(
    this._images[this._imageIndex].byteWidth + 1,
    this._reverseFilterLine.bind(this)
  );
};

Filter.prototype._unFilterType1 = function (
  rawData,
  unfilteredLine,
  byteWidth
) {
  let xComparison = this._xComparison;
  let xBiggerThan = xComparison - 1;

  for (let x = 0; x < byteWidth; x++) {
    let rawByte = rawData[1 + x];
    let f1Left = x > xBiggerThan ? unfilteredLine[x - xComparison] : 0;
    unfilteredLine[x] = rawByte + f1Left;
  }
};

Filter.prototype._unFilterType2 = function (
  rawData,
  unfilteredLine,
  byteWidth
) {
  let lastLine = this._lastLine;

  for (let x = 0; x < byteWidth; x++) {
    let rawByte = rawData[1 + x];
    let f2Up = lastLine ? lastLine[x] : 0;
    unfilteredLine[x] = rawByte + f2Up;
  }
};

Filter.prototype._unFilterType3 = function (
  rawData,
  unfilteredLine,
  byteWidth
) {
  let xComparison = this._xComparison;
  let xBiggerThan = xComparison - 1;
  let lastLine = this._lastLine;

  for (let x = 0; x < byteWidth; x++) {
    let rawByte = rawData[1 + x];
    let f3Up = lastLine ? lastLine[x] : 0;
    let f3Left = x > xBiggerThan ? unfilteredLine[x - xComparison] : 0;
    let f3Add = Math.floor((f3Left + f3Up) / 2);
    unfilteredLine[x] = rawByte + f3Add;
  }
};

Filter.prototype._unFilterType4 = function (
  rawData,
  unfilteredLine,
  byteWidth
) {
  let xComparison = this._xComparison;
  let xBiggerThan = xComparison - 1;
  let lastLine = this._lastLine;

  for (let x = 0; x < byteWidth; x++) {
    let rawByte = rawData[1 + x];
    let f4Up = lastLine ? lastLine[x] : 0;
    let f4Left = x > xBiggerThan ? unfilteredLine[x - xComparison] : 0;
    let f4UpLeft = x > xBiggerThan && lastLine ? lastLine[x - xComparison] : 0;
    let f4Add = paethPredictor(f4Left, f4Up, f4UpLeft);
    unfilteredLine[x] = rawByte + f4Add;
  }
};

Filter.prototype._reverseFilterLine = function (rawData) {
  let filter = rawData[0];
  let unfilteredLine;
  let currentImage = this._images[this._imageIndex];
  let byteWidth = currentImage.byteWidth;

  if (filter === 0) {
    unfilteredLine = rawData.slice(1, byteWidth + 1);
  } else {
    unfilteredLine = Buffer.alloc(byteWidth);

    switch (filter) {
      case 1:
        this._unFilterType1(rawData, unfilteredLine, byteWidth);
        break;
      case 2:
        this._unFilterType2(rawData, unfilteredLine, byteWidth);
        break;
      case 3:
        this._unFilterType3(rawData, unfilteredLine, byteWidth);
        break;
      case 4:
        this._unFilterType4(rawData, unfilteredLine, byteWidth);
        break;
      default:
        throw new Error("Unrecognised filter type - " + filter);
    }
  }

  this.write(unfilteredLine);

  currentImage.lineIndex++;
  if (currentImage.lineIndex >= currentImage.height) {
    this._lastLine = null;
    this._imageIndex++;
    currentImage = this._images[this._imageIndex];
  } else {
    this._lastLine = unfilteredLine;
  }

  if (currentImage) {
    // read, using the byte width that may be from the new current image
    this.read(currentImage.byteWidth + 1, this._reverseFilterLine.bind(this));
  } else {
    this._lastLine = null;
    this.complete();
  }
};

}).call(this)}).call(this,require("buffer").Buffer)
},{"./interlace":11,"./paeth-predictor":15,"buffer":32}],10:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

function dePalette(indata, outdata, width, height, palette) {
  let pxPos = 0;
  // use values from palette
  for (let y = 0; y < height; y++) {
    for (let x = 0; x < width; x++) {
      let color = palette[indata[pxPos]];

      if (!color) {
        throw new Error("index " + indata[pxPos] + " not in palette");
      }

      for (let i = 0; i < 4; i++) {
        outdata[pxPos + i] = color[i];
      }
      pxPos += 4;
    }
  }
}

function replaceTransparentColor(indata, outdata, width, height, transColor) {
  let pxPos = 0;
  for (let y = 0; y < height; y++) {
    for (let x = 0; x < width; x++) {
      let makeTrans = false;

      if (transColor.length === 1) {
        if (transColor[0] === indata[pxPos]) {
          makeTrans = true;
        }
      } else if (
        transColor[0] === indata[pxPos] &&
        transColor[1] === indata[pxPos + 1] &&
        transColor[2] === indata[pxPos + 2]
      ) {
        makeTrans = true;
      }
      if (makeTrans) {
        for (let i = 0; i < 4; i++) {
          outdata[pxPos + i] = 0;
        }
      }
      pxPos += 4;
    }
  }
}

function scaleDepth(indata, outdata, width, height, depth) {
  let maxOutSample = 255;
  let maxInSample = Math.pow(2, depth) - 1;
  let pxPos = 0;

  for (let y = 0; y < height; y++) {
    for (let x = 0; x < width; x++) {
      for (let i = 0; i < 4; i++) {
        outdata[pxPos + i] = Math.floor(
          (indata[pxPos + i] * maxOutSample) / maxInSample + 0.5
        );
      }
      pxPos += 4;
    }
  }
}

module.exports = function (indata, imageData, skipRescale = false) {
  let depth = imageData.depth;
  let width = imageData.width;
  let height = imageData.height;
  let colorType = imageData.colorType;
  let transColor = imageData.transColor;
  let palette = imageData.palette;

  let outdata = indata; // only different for 16 bits

  if (colorType === 3) {
    // paletted
    dePalette(indata, outdata, width, height, palette);
  } else {
    if (transColor) {
      replaceTransparentColor(indata, outdata, width, height, transColor);
    }
    // if it needs scaling
    if (depth !== 8 && !skipRescale) {
      // if we need to change the buffer size
      if (depth === 16) {
        outdata = Buffer.alloc(width * height * 4);
      }
      scaleDepth(indata, outdata, width, height, depth);
    }
  }
  return outdata;
};

}).call(this)}).call(this,require("buffer").Buffer)
},{"buffer":32}],11:[function(require,module,exports){
"use strict";

// Adam 7
//   0 1 2 3 4 5 6 7
// 0 x 6 4 6 x 6 4 6
// 1 7 7 7 7 7 7 7 7
// 2 5 6 5 6 5 6 5 6
// 3 7 7 7 7 7 7 7 7
// 4 3 6 4 6 3 6 4 6
// 5 7 7 7 7 7 7 7 7
// 6 5 6 5 6 5 6 5 6
// 7 7 7 7 7 7 7 7 7

let imagePasses = [
  {
    // pass 1 - 1px
    x: [0],
    y: [0],
  },
  {
    // pass 2 - 1px
    x: [4],
    y: [0],
  },
  {
    // pass 3 - 2px
    x: [0, 4],
    y: [4],
  },
  {
    // pass 4 - 4px
    x: [2, 6],
    y: [0, 4],
  },
  {
    // pass 5 - 8px
    x: [0, 2, 4, 6],
    y: [2, 6],
  },
  {
    // pass 6 - 16px
    x: [1, 3, 5, 7],
    y: [0, 2, 4, 6],
  },
  {
    // pass 7 - 32px
    x: [0, 1, 2, 3, 4, 5, 6, 7],
    y: [1, 3, 5, 7],
  },
];

exports.getImagePasses = function (width, height) {
  let images = [];
  let xLeftOver = width % 8;
  let yLeftOver = height % 8;
  let xRepeats = (width - xLeftOver) / 8;
  let yRepeats = (height - yLeftOver) / 8;
  for (let i = 0; i < imagePasses.length; i++) {
    let pass = imagePasses[i];
    let passWidth = xRepeats * pass.x.length;
    let passHeight = yRepeats * pass.y.length;
    for (let j = 0; j < pass.x.length; j++) {
      if (pass.x[j] < xLeftOver) {
        passWidth++;
      } else {
        break;
      }
    }
    for (let j = 0; j < pass.y.length; j++) {
      if (pass.y[j] < yLeftOver) {
        passHeight++;
      } else {
        break;
      }
    }
    if (passWidth > 0 && passHeight > 0) {
      images.push({ width: passWidth, height: passHeight, index: i });
    }
  }
  return images;
};

exports.getInterlaceIterator = function (width) {
  return function (x, y, pass) {
    let outerXLeftOver = x % imagePasses[pass].x.length;
    let outerX =
      ((x - outerXLeftOver) / imagePasses[pass].x.length) * 8 +
      imagePasses[pass].x[outerXLeftOver];
    let outerYLeftOver = y % imagePasses[pass].y.length;
    let outerY =
      ((y - outerYLeftOver) / imagePasses[pass].y.length) * 8 +
      imagePasses[pass].y[outerYLeftOver];
    return outerX * 4 + outerY * width * 4;
  };
};

},{}],12:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

let util = require("util");
let Stream = require("stream");
let constants = require("./constants");
let Packer = require("./packer");

let PackerAsync = (module.exports = function (opt) {
  Stream.call(this);

  let options = opt || {};

  this._packer = new Packer(options);
  this._deflate = this._packer.createDeflate();

  this.readable = true;
});
util.inherits(PackerAsync, Stream);

PackerAsync.prototype.pack = function (data, width, height, gamma) {
  // Signature
  this.emit("data", Buffer.from(constants.PNG_SIGNATURE));
  this.emit("data", this._packer.packIHDR(width, height));

  if (gamma) {
    this.emit("data", this._packer.packGAMA(gamma));
  }

  let filteredData = this._packer.filterData(data, width, height);

  // compress it
  this._deflate.on("error", this.emit.bind(this, "error"));

  this._deflate.on(
    "data",
    function (compressedData) {
      this.emit("data", this._packer.packIDAT(compressedData));
    }.bind(this)
  );

  this._deflate.on(
    "end",
    function () {
      this.emit("data", this._packer.packIEND());
      this.emit("end");
    }.bind(this)
  );

  this._deflate.end(filteredData);
};

}).call(this)}).call(this,require("buffer").Buffer)
},{"./constants":4,"./packer":14,"buffer":32,"stream":65,"util":84}],13:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

let hasSyncZlib = true;
let zlib = require("zlib");
if (!zlib.deflateSync) {
  hasSyncZlib = false;
}
let constants = require("./constants");
let Packer = require("./packer");

module.exports = function (metaData, opt) {
  if (!hasSyncZlib) {
    throw new Error(
      "To use the sync capability of this library in old node versions, please pin pngjs to v2.3.0"
    );
  }

  let options = opt || {};

  let packer = new Packer(options);

  let chunks = [];

  // Signature
  chunks.push(Buffer.from(constants.PNG_SIGNATURE));

  // Header
  chunks.push(packer.packIHDR(metaData.width, metaData.height));

  if (metaData.gamma) {
    chunks.push(packer.packGAMA(metaData.gamma));
  }

  let filteredData = packer.filterData(
    metaData.data,
    metaData.width,
    metaData.height
  );

  // compress it
  let compressedData = zlib.deflateSync(
    filteredData,
    packer.getDeflateOptions()
  );
  filteredData = null;

  if (!compressedData || !compressedData.length) {
    throw new Error("bad png - invalid compressed data response");
  }
  chunks.push(packer.packIDAT(compressedData));

  // End
  chunks.push(packer.packIEND());

  return Buffer.concat(chunks);
};

}).call(this)}).call(this,require("buffer").Buffer)
},{"./constants":4,"./packer":14,"buffer":32,"zlib":31}],14:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

let constants = require("./constants");
let CrcStream = require("./crc");
let bitPacker = require("./bitpacker");
let filter = require("./filter-pack");
let zlib = require("zlib");

let Packer = (module.exports = function (options) {
  this._options = options;

  options.deflateChunkSize = options.deflateChunkSize || 32 * 1024;
  options.deflateLevel =
    options.deflateLevel != null ? options.deflateLevel : 9;
  options.deflateStrategy =
    options.deflateStrategy != null ? options.deflateStrategy : 3;
  options.inputHasAlpha =
    options.inputHasAlpha != null ? options.inputHasAlpha : true;
  options.deflateFactory = options.deflateFactory || zlib.createDeflate;
  options.bitDepth = options.bitDepth || 8;
  // This is outputColorType
  options.colorType =
    typeof options.colorType === "number"
      ? options.colorType
      : constants.COLORTYPE_COLOR_ALPHA;
  options.inputColorType =
    typeof options.inputColorType === "number"
      ? options.inputColorType
      : constants.COLORTYPE_COLOR_ALPHA;

  if (
    [
      constants.COLORTYPE_GRAYSCALE,
      constants.COLORTYPE_COLOR,
      constants.COLORTYPE_COLOR_ALPHA,
      constants.COLORTYPE_ALPHA,
    ].indexOf(options.colorType) === -1
  ) {
    throw new Error(
      "option color type:" + options.colorType + " is not supported at present"
    );
  }
  if (
    [
      constants.COLORTYPE_GRAYSCALE,
      constants.COLORTYPE_COLOR,
      constants.COLORTYPE_COLOR_ALPHA,
      constants.COLORTYPE_ALPHA,
    ].indexOf(options.inputColorType) === -1
  ) {
    throw new Error(
      "option input color type:" +
        options.inputColorType +
        " is not supported at present"
    );
  }
  if (options.bitDepth !== 8 && options.bitDepth !== 16) {
    throw new Error(
      "option bit depth:" + options.bitDepth + " is not supported at present"
    );
  }
});

Packer.prototype.getDeflateOptions = function () {
  return {
    chunkSize: this._options.deflateChunkSize,
    level: this._options.deflateLevel,
    strategy: this._options.deflateStrategy,
  };
};

Packer.prototype.createDeflate = function () {
  return this._options.deflateFactory(this.getDeflateOptions());
};

Packer.prototype.filterData = function (data, width, height) {
  // convert to correct format for filtering (e.g. right bpp and bit depth)
  let packedData = bitPacker(data, width, height, this._options);

  // filter pixel data
  let bpp = constants.COLORTYPE_TO_BPP_MAP[this._options.colorType];
  let filteredData = filter(packedData, width, height, this._options, bpp);
  return filteredData;
};

Packer.prototype._packChunk = function (type, data) {
  let len = data ? data.length : 0;
  let buf = Buffer.alloc(len + 12);

  buf.writeUInt32BE(len, 0);
  buf.writeUInt32BE(type, 4);

  if (data) {
    data.copy(buf, 8);
  }

  buf.writeInt32BE(
    CrcStream.crc32(buf.slice(4, buf.length - 4)),
    buf.length - 4
  );
  return buf;
};

Packer.prototype.packGAMA = function (gamma) {
  let buf = Buffer.alloc(4);
  buf.writeUInt32BE(Math.floor(gamma * constants.GAMMA_DIVISION), 0);
  return this._packChunk(constants.TYPE_gAMA, buf);
};

Packer.prototype.packIHDR = function (width, height) {
  let buf = Buffer.alloc(13);
  buf.writeUInt32BE(width, 0);
  buf.writeUInt32BE(height, 4);
  buf[8] = this._options.bitDepth; // Bit depth
  buf[9] = this._options.colorType; // colorType
  buf[10] = 0; // compression
  buf[11] = 0; // filter
  buf[12] = 0; // interlace

  return this._packChunk(constants.TYPE_IHDR, buf);
};

Packer.prototype.packIDAT = function (data) {
  return this._packChunk(constants.TYPE_IDAT, data);
};

Packer.prototype.packIEND = function () {
  return this._packChunk(constants.TYPE_IEND, null);
};

}).call(this)}).call(this,require("buffer").Buffer)
},{"./bitpacker":2,"./constants":4,"./crc":5,"./filter-pack":6,"buffer":32,"zlib":31}],15:[function(require,module,exports){
"use strict";

module.exports = function paethPredictor(left, above, upLeft) {
  let paeth = left + above - upLeft;
  let pLeft = Math.abs(paeth - left);
  let pAbove = Math.abs(paeth - above);
  let pUpLeft = Math.abs(paeth - upLeft);

  if (pLeft <= pAbove && pLeft <= pUpLeft) {
    return left;
  }
  if (pAbove <= pUpLeft) {
    return above;
  }
  return upLeft;
};

},{}],16:[function(require,module,exports){
"use strict";

let util = require("util");
let zlib = require("zlib");
let ChunkStream = require("./chunkstream");
let FilterAsync = require("./filter-parse-async");
let Parser = require("./parser");
let bitmapper = require("./bitmapper");
let formatNormaliser = require("./format-normaliser");

let ParserAsync = (module.exports = function (options) {
  ChunkStream.call(this);

  this._parser = new Parser(options, {
    read: this.read.bind(this),
    error: this._handleError.bind(this),
    metadata: this._handleMetaData.bind(this),
    gamma: this.emit.bind(this, "gamma"),
    palette: this._handlePalette.bind(this),
    transColor: this._handleTransColor.bind(this),
    finished: this._finished.bind(this),
    inflateData: this._inflateData.bind(this),
    simpleTransparency: this._simpleTransparency.bind(this),
    headersFinished: this._headersFinished.bind(this),
  });
  this._options = options;
  this.writable = true;

  this._parser.start();
});
util.inherits(ParserAsync, ChunkStream);

ParserAsync.prototype._handleError = function (err) {
  this.emit("error", err);

  this.writable = false;

  this.destroy();

  if (this._inflate && this._inflate.destroy) {
    this._inflate.destroy();
  }

  if (this._filter) {
    this._filter.destroy();
    // For backward compatibility with Node 7 and below.
    // Suppress errors due to _inflate calling write() even after
    // it's destroy()'ed.
    this._filter.on("error", function () {});
  }

  this.errord = true;
};

ParserAsync.prototype._inflateData = function (data) {
  if (!this._inflate) {
    if (this._bitmapInfo.interlace) {
      this._inflate = zlib.createInflate();

      this._inflate.on("error", this.emit.bind(this, "error"));
      this._filter.on("complete", this._complete.bind(this));

      this._inflate.pipe(this._filter);
    } else {
      let rowSize =
        ((this._bitmapInfo.width *
          this._bitmapInfo.bpp *
          this._bitmapInfo.depth +
          7) >>
          3) +
        1;
      let imageSize = rowSize * this._bitmapInfo.height;
      let chunkSize = Math.max(imageSize, zlib.Z_MIN_CHUNK);

      this._inflate = zlib.createInflate({ chunkSize: chunkSize });
      let leftToInflate = imageSize;

      let emitError = this.emit.bind(this, "error");
      this._inflate.on("error", function (err) {
        if (!leftToInflate) {
          return;
        }

        emitError(err);
      });
      this._filter.on("complete", this._complete.bind(this));

      let filterWrite = this._filter.write.bind(this._filter);
      this._inflate.on("data", function (chunk) {
        if (!leftToInflate) {
          return;
        }

        if (chunk.length > leftToInflate) {
          chunk = chunk.slice(0, leftToInflate);
        }

        leftToInflate -= chunk.length;

        filterWrite(chunk);
      });

      this._inflate.on("end", this._filter.end.bind(this._filter));
    }
  }
  this._inflate.write(data);
};

ParserAsync.prototype._handleMetaData = function (metaData) {
  this._metaData = metaData;
  this._bitmapInfo = Object.create(metaData);

  this._filter = new FilterAsync(this._bitmapInfo);
};

ParserAsync.prototype._handleTransColor = function (transColor) {
  this._bitmapInfo.transColor = transColor;
};

ParserAsync.prototype._handlePalette = function (palette) {
  this._bitmapInfo.palette = palette;
};

ParserAsync.prototype._simpleTransparency = function () {
  this._metaData.alpha = true;
};

ParserAsync.prototype._headersFinished = function () {
  // Up until this point, we don't know if we have a tRNS chunk (alpha)
  // so we can't emit metadata any earlier
  this.emit("metadata", this._metaData);
};

ParserAsync.prototype._finished = function () {
  if (this.errord) {
    return;
  }

  if (!this._inflate) {
    this.emit("error", "No Inflate block");
  } else {
    // no more data to inflate
    this._inflate.end();
  }
};

ParserAsync.prototype._complete = function (filteredData) {
  if (this.errord) {
    return;
  }

  let normalisedBitmapData;

  try {
    let bitmapData = bitmapper.dataToBitMap(filteredData, this._bitmapInfo);

    normalisedBitmapData = formatNormaliser(
      bitmapData,
      this._bitmapInfo,
      this._options.skipRescale
    );
    bitmapData = null;
  } catch (ex) {
    this._handleError(ex);
    return;
  }

  this.emit("parsed", normalisedBitmapData);
};

},{"./bitmapper":1,"./chunkstream":3,"./filter-parse-async":7,"./format-normaliser":10,"./parser":18,"util":84,"zlib":31}],17:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

let hasSyncZlib = true;
let zlib = require("zlib");
let inflateSync = require("./sync-inflate");
if (!zlib.deflateSync) {
  hasSyncZlib = false;
}
let SyncReader = require("./sync-reader");
let FilterSync = require("./filter-parse-sync");
let Parser = require("./parser");
let bitmapper = require("./bitmapper");
let formatNormaliser = require("./format-normaliser");

module.exports = function (buffer, options) {
  if (!hasSyncZlib) {
    throw new Error(
      "To use the sync capability of this library in old node versions, please pin pngjs to v2.3.0"
    );
  }

  let err;
  function handleError(_err_) {
    err = _err_;
  }

  let metaData;
  function handleMetaData(_metaData_) {
    metaData = _metaData_;
  }

  function handleTransColor(transColor) {
    metaData.transColor = transColor;
  }

  function handlePalette(palette) {
    metaData.palette = palette;
  }

  function handleSimpleTransparency() {
    metaData.alpha = true;
  }

  let gamma;
  function handleGamma(_gamma_) {
    gamma = _gamma_;
  }

  let inflateDataList = [];
  function handleInflateData(inflatedData) {
    inflateDataList.push(inflatedData);
  }

  let reader = new SyncReader(buffer);

  let parser = new Parser(options, {
    read: reader.read.bind(reader),
    error: handleError,
    metadata: handleMetaData,
    gamma: handleGamma,
    palette: handlePalette,
    transColor: handleTransColor,
    inflateData: handleInflateData,
    simpleTransparency: handleSimpleTransparency,
  });

  parser.start();
  reader.process();

  if (err) {
    throw err;
  }

  //join together the inflate datas
  let inflateData = Buffer.concat(inflateDataList);
  inflateDataList.length = 0;

  let inflatedData;
  if (metaData.interlace) {
    inflatedData = zlib.inflateSync(inflateData);
  } else {
    let rowSize =
      ((metaData.width * metaData.bpp * metaData.depth + 7) >> 3) + 1;
    let imageSize = rowSize * metaData.height;
    inflatedData = inflateSync(inflateData, {
      chunkSize: imageSize,
      maxLength: imageSize,
    });
  }
  inflateData = null;

  if (!inflatedData || !inflatedData.length) {
    throw new Error("bad png - invalid inflate data response");
  }

  let unfilteredData = FilterSync.process(inflatedData, metaData);
  inflateData = null;

  let bitmapData = bitmapper.dataToBitMap(unfilteredData, metaData);
  unfilteredData = null;

  let normalisedBitmapData = formatNormaliser(
    bitmapData,
    metaData,
    options.skipRescale
  );

  metaData.data = normalisedBitmapData;
  metaData.gamma = gamma || 0;

  return metaData;
};

}).call(this)}).call(this,require("buffer").Buffer)
},{"./bitmapper":1,"./filter-parse-sync":8,"./format-normaliser":10,"./parser":18,"./sync-inflate":21,"./sync-reader":22,"buffer":32,"zlib":31}],18:[function(require,module,exports){
(function (Buffer){(function (){
"use strict";

let constants = require("./constants");
let CrcCalculator = require("./crc");

let Parser = (module.exports = function (options, dependencies) {
  this._options = options;
  options.checkCRC = options.checkCRC !== false;

  this._hasIHDR = false;
  this._hasIEND = false;
  this._emittedHeadersFinished = false;

  // input flags/metadata
  this._palette = [];
  this._colorType = 0;

  this._chunks = {};
  this._chunks[constants.TYPE_IHDR] = this._handleIHDR.bind(this);
  this._chunks[constants.TYPE_IEND] = this._handleIEND.bind(this);
  this._chunks[constants.TYPE_IDAT] = this._handleIDAT.bind(this);
  this._chunks[constants.TYPE_PLTE] = this._handlePLTE.bind(this);
  this._chunks[constants.TYPE_tRNS] = this._handleTRNS.bind(this);
  this._chunks[constants.TYPE_gAMA] = this._handleGAMA.bind(this);

  this.read = dependencies.read;
  this.error = dependencies.error;
  this.metadata = dependencies.metadata;
  this.gamma = dependencies.gamma;
  this.transColor = dependencies.transColor;
  this.palette = dependencies.palette;
  this.parsed = dependencies.parsed;
  this.inflateData = dependencies.inflateData;
  this.finished = dependencies.finished;
  this.simpleTransparency = dependencies.simpleTransparency;
  this.headersFinished = dependencies.headersFinished || function () {};
});

Parser.prototype.start = function () {
  this.read(constants.PNG_SIGNATURE.length, this._parseSignature.bind(this));
};

Parser.prototype._parseSignature = function (data) {
  let signature = constants.PNG_SIGNATURE;

  for (let i = 0; i < signature.length; i++) {
    if (data[i] !== signature[i]) {
      this.error(new Error("Invalid file signature"));
      return;
    }
  }
  this.read(8, this._parseChunkBegin.bind(this));
};