Support for synchronous reading of PNG's

lib/crc.js

@@ -20,21 +20,11 @@
 
 'use strict';
 
-var util = require('util'),
-    Stream = require('stream');
-
-
-var CrcStream = module.exports = function() {
-    Stream.call(this);
-
+var CrcCalculator = module.exports = function() {
     this._crc = -1;
-
-    this.writable = true;
 };
-util.inherits(CrcStream, Stream);
 
-
-CrcStream.prototype.write = function(data) {
+CrcCalculator.prototype.write = function(data) {
 
     for (var i = 0; i < data.length; i++) {
         this._crc = crcTable[(this._crc ^ data[i]) & 0xff] ^ (this._crc >>> 8);
@@ -42,18 +32,12 @@ CrcStream.prototype.write = function(data) {
     return true;
 };
 
-CrcStream.prototype.end = function(data) {
-    if (data) this.write(data);
-
-    this.emit('crc', this.crc32());
-};
-
-CrcStream.prototype.crc32 = function() {
+CrcCalculator.prototype.crc32 = function() {
     return this._crc ^ -1;
 };
 
 
-CrcStream.crc32 = function(buf) {
+CrcCalculator.crc32 = function(buf) {
 
     var crc = -1;
     for (var i = 0; i < buf.length; i++) {

lib/filter-async.js

@@ -0,0 +1,38 @@
+// Copyright (c) 2012 Kuba Niegowski
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+'use strict';
+
+var util = require('util'),
+    ChunkStream = require('./chunkstream'),
+  Filter = require('./filter');
+
+
+var FilterAsync = module.exports = function(width, height, Bpp, data, options) {
+    ChunkStream.call(this);
+
+    this._filter = new Filter(width, height, Bpp, data, options, {
+        read: this.read.bind(this),
+        complete: this.emit.bind(this, 'complete')
+    });
+
+    this._filter.start();
+};
+util.inherits(FilterAsync, ChunkStream);

lib/filter-sync.js

@@ -0,0 +1,37 @@
+// Copyright (c) 2012 Kuba Niegowski
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+'use strict';
+
+var SyncReader = require('./sync-reader'),
+  Filter = require('./filter');
+
+
+exports.process = function(buffer, width, height, Bpp, outData, options) {
+
+    var reader = new SyncReader(buffer);
+    var filter = new Filter(width, height, Bpp, outData, options, {
+        read: reader.read.bind(reader),
+        complete: function(){}
+    });
+
+    filter.start();
+    reader.process();
+};

lib/filter.js

@@ -21,12 +21,10 @@
 'use strict';
 
 var util = require('util'),
-    zlib = require('zlib'),
     ChunkStream = require('./chunkstream');
 
 
-var Filter = module.exports = function(width, height, Bpp, data, options) {
-    ChunkStream.call(this);
+var Filter = module.exports = function(width, height, Bpp, data, options, dependencies) {
 
     this._width = width;
     this._height = height;
@@ -50,10 +48,13 @@ var Filter = module.exports = function(width, height, Bpp, data, options) {
         4: this._filterPaeth.bind(this)
     };
 
-    this.read(this._width * Bpp + 1, this._reverseFilterLine.bind(this));
+    this.read = dependencies.read;
+    this.complete = dependencies.complete;
 };
-util.inherits(Filter, ChunkStream);
 
+Filter.prototype.start = function() {
+    this.read(this._width * this._Bpp + 1, this._reverseFilterLine.bind(this));
+};
 
 var pixelBppMap = {
     1: { // L
@@ -167,7 +168,7 @@ Filter.prototype._reverseFilterLine = function(rawData) {
     if (this._line < this._height)
         this.read(this._width * this._Bpp + 1, this._reverseFilterLine.bind(this));
     else
-        this.emit('complete', this._data, this._width, this._height);
+        this.complete(this._data, this._width, this._height);
 };
 
 

lib/packer.js

@@ -50,7 +50,7 @@ Packer.prototype.pack = function(data, width, height) {
     this.emit('data', this._packIHDR(width, height));
 
     // filter pixel data
-    var filter = new Filter(width, height, 4, data, this._options);
+    var filter = new Filter(width, height, 4, data, this._options, {});
     var data = filter.filter();
 
     // compress it

lib/parser-async.js

@@ -0,0 +1,97 @@
+// Copyright (c) 2012 Kuba Niegowski
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+'use strict';
+
+
+var util = require('util'),
+    zlib = require('zlib'),
+    ChunkStream = require('./chunkstream'),
+    FilterAsync = require('./filter-async'),
+    Parser = require('./parser');
+
+
+var ParserAsync = module.exports = function(options) {
+    ChunkStream.call(this);
+
+    this._parser = new Parser(options, {
+        read: this.read.bind(this),
+        error: this.emit.bind(this, "error"),
+        metadata: this.emit.bind(this, "metadata"),
+        gamma: this.emit.bind(this, "gamma"),
+        finished: this._finished.bind(this),
+        inflateData: this._inflateData.bind(this),
+        createData: this._createData.bind(this)
+    });
+    this._options = options;
+    this.writable = true;
+
+    this.on('error', this._handleError.bind(this));
+    this._parser.start();
+};
+util.inherits(ParserAsync, ChunkStream);
+
+
+ParserAsync.prototype._handleError = function() {
+
+    this.writable = false;
+
+    this.destroy();
+
+    if (this._inflate && this._inflate.destroy) {
+        this._inflate.destroy();
+    }
+};
+
+ParserAsync.prototype._inflateData = function(data) {
+    if (!this._inflate) {
+        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);
+    }
+    this._inflate.write(data);
+};
+
+ParserAsync.prototype._createData = function(width, height, bpp) {
+    this._data = new Buffer(width * height * 4);
+    this._filter = new FilterAsync(
+      width, height,
+      bpp,
+      this._data,
+      this._options
+    );
+    return this._data;
+};
+
+ParserAsync.prototype._finished = function(data) {
+    // no more data to inflate
+    this._inflate.end();
+    this.destroySoon();
+};
+
+ParserAsync.prototype._complete = function(data, width, height) {
+
+    data = this._parser.reverseFiltered(data, width, height);
+
+    this.emit('parsed', data);
+};

lib/parser-sync.js

@@ -0,0 +1,87 @@
+// Copyright (c) 2012 Kuba Niegowski
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+'use strict';
+
+
+var zlib = require('zlib'),
+    SyncReader = require('./sync-reader'),
+    FilterSync = require('./filter-sync'),
+    Parser = require('./parser');
+
+
+var ParserSync = module.exports = function(buffer, options) {
+
+    var reader = new SyncReader(buffer);
+
+    this._inflateDataList = [];
+    this._parser = new Parser(options, {
+        read: reader.read.bind(reader),
+        error: this._handleError.bind(this),
+        metadata: this._metaData.bind(this),
+        gamma: this._gamma.bind(this),
+        finished: function() {},
+        inflateData: this._inflateData.bind(this),
+        createData: this._createData.bind(this)
+    });
+    this._options = options;
+
+    this._parser.start();
+    reader.process();
+
+    //join together the inflate datas
+    var inflateData = Buffer.concat(this._inflateDataList);
+
+    var data = zlib.inflateSync(inflateData);
+
+    FilterSync.process(
+      data,
+      this._width, this._height,
+      this._bpp,
+      this._data,
+      this._options
+    );
+
+    this.data = this._parser.reverseFiltered(this._data, this._width, this._height);
+};
+
+ParserSync.prototype._handleError = function(err) {
+    this.err = err;
+};
+
+ParserSync.prototype._metaData = function(metaData) {
+    this.metaData = metaData;
+};
+
+ParserSync.prototype._gamma = function(gamma) {
+    this.gamma = gamma;
+};
+
+ParserSync.prototype._inflateData = function(data) {
+    this._inflateDataList.push(data);
+};
+
+ParserSync.prototype._createData = function(width, height, bpp) {
+    this._data = new Buffer(width * height * 4);
+    this._bpp = bpp;
+    this._width = width;
+    this._height = height;
+    return this._data;
+};

lib/parser.js

@@ -21,339 +21,302 @@
 'use strict';
 
 
-var util = require('util'),
-    zlib = require('zlib'),
-    CrcStream = require('./crc'),
-    ChunkStream = require('./chunkstream'),
-    constants = require('./constants'),
-    Filter = require('./filter');
+var constants = require('./constants'),
+  CrcCalculator = require('./crc');
 
 
-var Parser = module.exports = function(options) {
-    ChunkStream.call(this);
+var Parser = module.exports = function(options, dependencies) {
 
-    this._options = options;
-    options.checkCRC = options.checkCRC !== false;
+  this._options = options;
+  options.checkCRC = options.checkCRC !== false;
 
-    this._hasIHDR = false;
-    this._hasIEND = false;
+  this._hasIHDR = false;
+  this._hasIEND = false;
 
-    this._inflate = null;
-    this._filter = null;
-    this._crc = null;
+  // input flags/metadata
+  this._palette = [];
+  this._colorType = 0;
 
-    // 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._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.writable = true;
-
-    this.on('error', this._handleError.bind(this));
-    this._handleSignature();
-};
-util.inherits(Parser, ChunkStream);
-
-
-Parser.prototype._handleError = function() {
-
-    this.writable = false;
-
-    this.destroy();
-
-    if (this._inflate)
-        this._inflate.destroy();
+  this.read = dependencies.read;
+  this.error = dependencies.error;
+  this.metadata = dependencies.metadata;
+  this.gamma = dependencies.gamma;
+  this.parsed = dependencies.parsed;
+  this.createData = dependencies.createData;
+  this.inflateData = dependencies.inflateData;
+    this.finished = dependencies.finished;
 };
 
-Parser.prototype._handleSignature = function() {
-    this.read(constants.PNG_SIGNATURE.length,
-        this._parseSignature.bind(this)
-    );
+var colorTypeToBppMap = {
+  0: 1,
+  2: 3,
+  3: 1,
+  4: 2,
+  6: 4
+};
+
+Parser.prototype.start = function() {
+  this.read(constants.PNG_SIGNATURE.length,
+    this._parseSignature.bind(this)
+  );
 };
 
 Parser.prototype._parseSignature = function(data) {
 
-    var signature = constants.PNG_SIGNATURE;
+  var signature = constants.PNG_SIGNATURE;
 
-    for (var i = 0; i < signature.length; i++) {
-        if (data[i] != signature[i]) {
-            this.emit('error', new Error('Invalid file signature'));
-            return;
-        }
+  for (var 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));
+  }
+  this.read(8, this._parseChunkBegin.bind(this));
 };
 
 Parser.prototype._parseChunkBegin = function(data) {
 
-    // chunk content length
-    var length = data.readUInt32BE(0);
+  // chunk content length
+  var length = data.readUInt32BE(0);
 
-    // chunk type
-    var type = data.readUInt32BE(4),
-        name = '';
-    for (var i = 4; i < 8; i++)
-        name += String.fromCharCode(data[i]);
+  // chunk type
+  var type = data.readUInt32BE(4),
+    name = '';
+  for (var i = 4; i < 8; i++) {
+    name += String.fromCharCode(data[i]);
+  }
 
-    // console.log('chunk ', name, length);
+  //console.log('chunk ', name, length);
 
-    // chunk flags
-    var ancillary  = !!(data[4] & 0x20),  // or critical
-        priv       = !!(data[5] & 0x20),  // or public
-        safeToCopy = !!(data[7] & 0x20);  // or unsafe
+  // chunk flags
+  var ancillary  = !!(data[4] & 0x20),  // or critical
+    priv       = !!(data[5] & 0x20),  // or public
+    safeToCopy = !!(data[7] & 0x20);  // or unsafe
 
-    if (!this._hasIHDR && type != constants.TYPE_IHDR) {
-        this.emit('error', new Error('Expected IHDR on beggining'));
-        return;
-    }
+  if (!this._hasIHDR && type != constants.TYPE_IHDR) {
+    this.error(new Error('Expected IHDR on beggining'));
+    return;
+  }
 
-    this._crc = new CrcStream();
-    this._crc.write(new Buffer(name));
+  this._crc = new CrcCalculator();
+  this._crc.write(new Buffer(name));
 
-    if (this._chunks[type]) {
-        return this._chunks[type](length);
+  if (this._chunks[type]) {
+    return this._chunks[type](length);
 
-    } else if (!ancillary) {
-        this.emit('error', new Error('Unsupported critical chunk type ' + name));
-        return;
-    } else {
-        this.read(length + 4, this._skipChunk.bind(this));
-    }
+  } else if (!ancillary) {
+    this.error(new Error('Unsupported critical chunk type ' + name));
+    return;
+  } else {
+    this.read(length + 4, this._skipChunk.bind(this));
+  }
 };
 
 Parser.prototype._skipChunk = function(data) {
-    this.read(8, this._parseChunkBegin.bind(this));
+  this.read(8, this._parseChunkBegin.bind(this));
 };
 
 Parser.prototype._handleChunkEnd = function() {
-    this.read(4, this._parseChunkEnd.bind(this));
+  this.read(4, this._parseChunkEnd.bind(this));
 };
 
 Parser.prototype._parseChunkEnd = function(data) {
 
-    var fileCrc = data.readInt32BE(0),
-        calcCrc = this._crc.crc32();
+  var fileCrc = data.readInt32BE(0),
+    calcCrc = this._crc.crc32();
 
-    // check CRC
-    if (this._options.checkCRC && calcCrc != fileCrc) {
-        this.emit('error', new Error('Crc error'));
-        return;
-    }
+  // check CRC
+  if (this._options.checkCRC && calcCrc != fileCrc) {
+    this.error(new Error('Crc error - ' + fileCrc + " - " + calcCrc));
+    return;
+  }
 
-    if (this._hasIEND) {
-        this.destroySoon();
-
-    } else {
-        this.read(8, this._parseChunkBegin.bind(this));
-    }
+  if (!this._hasIEND) {
+    this.read(8, this._parseChunkBegin.bind(this));
+  }
 };
 
-
 Parser.prototype._handleIHDR = function(length) {
-    this.read(length, this._parseIHDR.bind(this));
+  this.read(length, this._parseIHDR.bind(this));
 };
 Parser.prototype._parseIHDR = function(data) {
 
-    this._crc.write(data);
+  this._crc.write(data);
 
-    var width = data.readUInt32BE(0),
-        height = data.readUInt32BE(4),
-        depth = data[8],
-        colorType = data[9], // bits: 1 palette, 2 color, 4 alpha
-        compr = data[10],
-        filter = data[11],
-        interlace = data[12];
+  var width = data.readUInt32BE(0),
+    height = data.readUInt32BE(4),
+    depth = data[8],
+    colorType = data[9], // bits: 1 palette, 2 color, 4 alpha
+    compr = data[10],
+    filter = data[11],
+    interlace = data[12];
 
-    // console.log('    width', width, 'height', height,
-    //     'depth', depth, 'colorType', colorType,
-    //     'compr', compr, 'filter', filter, 'interlace', interlace
-    // );
+  // console.log('    width', width, 'height', height,
+  //     'depth', depth, 'colorType', colorType,
+  //     'compr', compr, 'filter', filter, 'interlace', interlace
+  // );
 
-    if (depth != 8) {
-        this.emit('error', new Error('Unsupported bit depth ' + depth));
-        return;
-    }
-    if (!(colorType in colorTypeToBppMap)) {
-        this.emit('error', new Error('Unsupported color type'));
-        return;
-    }
-    if (compr != 0) {
-        this.emit('error', new Error('Unsupported compression method'));
-        return;
-    }
-    if (filter != 0) {
-        this.emit('error', new Error('Unsupported filter method'));
-        return;
-    }
-    if (interlace != 0) {
-        this.emit('error', new Error('Unsupported interlace method'));
-        return;
-    }
+  if (depth != 8) {
+    this.error(new Error('Unsupported bit depth ' + depth));
+    return;
+  }
+  if (!(colorType in colorTypeToBppMap)) {
+    this.error(new Error('Unsupported color type'));
+    return;
+  }
+  if (compr != 0) {
+    this.error(new Error('Unsupported compression method'));
+    return;
+  }
+  if (filter != 0) {
+    this.error(new Error('Unsupported filter method'));
+    return;
+  }
+  if (interlace != 0) {
+    this.error(new Error('Unsupported interlace method'));
+    return;
+  }
 
-    this._colorType = colorType;
+  this._colorType = colorType;
 
-    this._data = new Buffer(width * height * 4);
-    this._filter = new Filter(
-        width, height,
-        colorTypeToBppMap[this._colorType],
-        this._data,
-        this._options
-    );
+  this._data = this.createData(width, height, colorTypeToBppMap[this._colorType]);
 
-    this._hasIHDR = true;
+  this._hasIHDR = true;
 
-    this.emit('metadata', {
-        width: width,
-        height: height,
-        palette: !!(colorType & constants.COLOR_PALETTE),
-        color: !!(colorType & constants.COLOR_COLOR),
-        alpha: !!(colorType & constants.COLOR_ALPHA),
-        data: this._data
-    });
+  this.metadata({
+    width: width,
+    height: height,
+    palette: !!(colorType & constants.COLOR_PALETTE),
+    color: !!(colorType & constants.COLOR_COLOR),
+    alpha: !!(colorType & constants.COLOR_ALPHA),
+    data: this._data
+  });
 
-    this._handleChunkEnd();
+  this._handleChunkEnd();
 };
 
 
 Parser.prototype._handlePLTE = function(length) {
-    this.read(length, this._parsePLTE.bind(this));
+  this.read(length, this._parsePLTE.bind(this));
 };
 Parser.prototype._parsePLTE = function(data) {
 
-    this._crc.write(data);
+  this._crc.write(data);
 
-    var entries = Math.floor(data.length / 3);
-    // console.log('Palette:', entries);
+  var entries = Math.floor(data.length / 3);
+  // console.log('Palette:', entries);
 
-    for (var i = 0; i < entries; i++) {
-        this._palette.push([
-            data.readUInt8(i * 3),
-            data.readUInt8(i * 3 + 1),
-            data.readUInt8(i * 3 + 2 ),
-            0xff
-        ]);
-    }
+  for (var i = 0; i < entries; i++) {
+    this._palette.push([
+      data.readUInt8(i * 3),
+      data.readUInt8(i * 3 + 1),
+      data.readUInt8(i * 3 + 2 ),
+      0xff
+    ]);
+  }
 
-    this._handleChunkEnd();
+  this._handleChunkEnd();
 };
 
 Parser.prototype._handleTRNS = function(length) {
-    this.read(length, this._parseTRNS.bind(this));
+  this.read(length, this._parseTRNS.bind(this));
 };
 Parser.prototype._parseTRNS = function(data) {
 
-    this._crc.write(data);
+  this._crc.write(data);
 
-    // palette
-    if (this._colorType == 3) {
-        if (this._palette.length == 0) {
-            this.emit('error', new Error('Transparency chunk must be after palette'));
-            return;
-        }
-        if (data.length > this._palette.length) {
-            this.emit('error', new Error('More transparent colors than palette size'));
-            return;
-        }
-        for (var i = 0; i < this._palette.length; i++) {
-            this._palette[i][3] = i < data.length ? data.readUInt8(i) : 0xff;
-        }
+  // palette
+  if (this._colorType == 3) {
+    if (this._palette.length == 0) {
+      this.error(new Error('Transparency chunk must be after palette'));
+      return;
     }
+    if (data.length > this._palette.length) {
+      this.error(new Error('More transparent colors than palette size'));
+      return;
+    }
+    for (var i = 0; i < this._palette.length; i++) {
+      this._palette[i][3] = i < data.length ? data.readUInt8(i) : 0xff;
+    }
+  }
 
-    // for colorType 0 (grayscale) and 2 (rgb)
-    // there might be one gray/color defined as transparent
+  // for colorType 0 (grayscale) and 2 (rgb)
+  // there might be one gray/color defined as transparent
 
-    this._handleChunkEnd();
+  this._handleChunkEnd();
 };
 
 Parser.prototype._handleGAMA = function(length) {
-    this.read(length, this._parseGAMA.bind(this));
+  this.read(length, this._parseGAMA.bind(this));
 };
 Parser.prototype._parseGAMA = function(data) {
 
-    this._crc.write(data);
-    this.emit('gamma', data.readUInt32BE(0) / 100000);
+  this._crc.write(data);
+  this.gamma(data.readUInt32BE(0) / 100000);
 
-    this._handleChunkEnd();
+  this._handleChunkEnd();
 };
 
 Parser.prototype._handleIDAT = function(length) {
-    this.read(-length, this._parseIDAT.bind(this, length));
+  this.read(-length, this._parseIDAT.bind(this, length));
 };
 Parser.prototype._parseIDAT = function(length, data) {
 
-    this._crc.write(data);
+  this._crc.write(data);
 
-    if (this._colorType == 3 && this._palette.length == 0)
-        throw new Error('Expected palette not found');
+  if (this._colorType == 3 && this._palette.length == 0)
+    throw new Error('Expected palette not found');
 
-    if (!this._inflate) {
-        this._inflate = zlib.createInflate();
+  this.inflateData(data);
+  length -= data.length;
 
-        this._inflate.on('error', this.emit.bind(this, 'error'));
-        this._filter.on('complete', this._reverseFiltered.bind(this));
-
-        this._inflate.pipe(this._filter);
-    }
-
-    this._inflate.write(data);
-    length -= data.length;
-
-    if (length > 0)
-        this._handleIDAT(length);
-    else
-        this._handleChunkEnd();
+  if (length > 0)
+    this._handleIDAT(length);
+  else
+    this._handleChunkEnd();
 };
 
 
 Parser.prototype._handleIEND = function(length) {
-    this.read(length, this._parseIEND.bind(this));
+  this.read(length, this._parseIEND.bind(this));
 };
 Parser.prototype._parseIEND = function(data) {
 
-    this._crc.write(data);
+  this._crc.write(data);
 
-    // no more data to inflate
-    this._inflate.end();
+  this._hasIEND = true;
+  this._handleChunkEnd();
 
-    this._hasIEND = true;
-    this._handleChunkEnd();
+  this.finished();
 };
 
+Parser.prototype.reverseFiltered = function(data, width, height) {
 
-var colorTypeToBppMap = {
-    0: 1,
-    2: 3,
-    3: 1,
-    4: 2,
-    6: 4
-};
+  if (this._colorType == 3) { // paletted
 
-Parser.prototype._reverseFiltered = function(data, width, height) {
+    // use values from palette
+    var pxLineLength = width << 2;
 
-    if (this._colorType == 3) { // paletted
+    for (var y = 0; y < height; y++) {
+      var pxRowPos = y * pxLineLength;
 
-        // use values from palette
-        var pxLineLength = width << 2;
+      for (var x = 0; x < width; x++) {
+        var pxPos = pxRowPos + (x << 2),
+          color = this._palette[data[pxPos]];
 
-        for (var y = 0; y < height; y++) {
-            var pxRowPos = y * pxLineLength;
-
-            for (var x = 0; x < width; x++) {
-                var pxPos = pxRowPos + (x << 2),
-                    color = this._palette[data[pxPos]];
-
-                for (var i = 0; i < 4; i++)
-                    data[pxPos + i] = color[i];
-            }
-        }
+        for (var i = 0; i < 4; i++)
+          data[pxPos + i] = color[i];
+      }
     }
-
-    this.emit('parsed', data);
+  }
+  return data;
 };
+

lib/png-sync.js

@@ -0,0 +1,42 @@
+// Copyright (c) 2012 Kuba Niegowski
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+'use strict';
+
+
+var Parser = require('./parser-sync');
+
+
+exports.read = function(buffer, options) {
+
+    options = options || {};
+    var parser = new Parser(buffer, options);
+
+    if (parser.err) {
+        throw parser.err;
+    }
+
+    return {
+        data: parser.data,
+        width: parser._width,
+        height: parser._height,
+        gamma: parser.gamma || 0
+    };
+};

lib/png.js

@@ -23,8 +23,9 @@
 
 var util = require('util'),
     Stream = require('stream'),
-    Parser = require('./parser'),
-    Packer = require('./packer');
+    Parser = require('./parser-async'),
+    Packer = require('./packer'),
+  PNGSync = require('./png-sync');
 
 
 var PNG = exports.PNG = function(options) {
@@ -34,7 +35,7 @@ var PNG = exports.PNG = function(options) {
 
     this.width = options.width || 0;
     this.height = options.height || 0;
-		
+
     this.data = this.width > 0 && this.height > 0
             ? new Buffer(4 * this.width * this.height) : null;
 
@@ -63,6 +64,7 @@ var PNG = exports.PNG = function(options) {
 };
 util.inherits(PNG, Stream);
 
+PNG.sync = PNGSync;
 
 PNG.prototype.pack = function() {
 
@@ -125,25 +127,46 @@ PNG.prototype._handleClose = function() {
         this.emit('close');
 };
 
-
-PNG.prototype.bitblt = function(dst, sx, sy, w, h, dx, dy) {
-
-    var src = this;
+PNG.bitblt = function(src, dst, sx, sy, w, h, dx, dy) {
 
     if (sx > src.width || sy > src.height
-            || sx + w > src.width || sy + h > src.height)
+      || sx + w > src.width || sy + h > src.height)
         throw new Error('bitblt reading outside image');
     if (dx > dst.width || dy > dst.height
-            || dx + w > dst.width || dy + h > dst.height)
+      || dx + w > dst.width || dy + h > dst.height)
         throw new Error('bitblt writing outside image');
 
     for (var y = 0; y < h; y++) {
         src.data.copy(dst.data,
-            ((dy + y) * dst.width + dx) << 2,
-            ((sy + y) * src.width + sx) << 2,
-            ((sy + y) * src.width + sx + w) << 2
+          ((dy + y) * dst.width + dx) << 2,
+          ((sy + y) * src.width + sx) << 2,
+          ((sy + y) * src.width + sx + w) << 2
         );
     }
+};
 
+
+PNG.prototype.bitblt = function(dst, sx, sy, w, h, dx, dy) {
+
+    PNG.bitblt(this, dst, sx, sy, w, h, dx, dy);
     return this;
 };
+
+PNG.adjustGamma = function(src) {
+    if (src.gamma) {
+        for (var y = 0; y < src.height; y++) {
+            for (var x = 0; x < src.width; x++) {
+                var idx = (src.width * y + x) << 2;
+
+                for (var i = 0; i < 3; i++) {
+                    var sample = src.data[idx + i] / 255;
+                    sample = Math.pow(sample, 1 / 2.2 / src.gamma);
+                    src.data[idx + i] = Math.round(sample * 255);
+                }
+            }
+        }
+        src.gamma = 0;
+    }
+};
+
+PNG.prototype.adjustGamma = function() { PNG.adjustGamma(this); };

lib/sync-reader.js

@@ -0,0 +1,70 @@
+// Copyright (c) 2012 Kuba Niegowski
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+'use strict';
+
+var SyncReader = module.exports = function (buffer) {
+
+  this._buffer = buffer;
+  this._reads = [];
+};
+
+SyncReader.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
+  });
+};
+
+SyncReader.prototype.process = function () {
+
+  // as long as there is any data and read requests
+  while (this._reads.length > 0 && this._buffer.length) {
+
+    var read = this._reads[0];
+
+    if (this._buffer.length && (this._buffer.length >= read.length || read.allowLess)) {
+
+      // ok there is any data so that we can satisfy this request
+      this._reads.shift(); // == read
+
+      var buf = this._buffer;
+
+      this._buffer = buf.slice(read.length);
+
+      read.func.call(this, buf.slice(0, read.length));
+
+    } else {
+        break;
+    }
+
+  }
+
+  if (this._reads.length > 0) {
+      return new Error('There are some read requests waitng on finished stream');
+  }
+
+  if (this._buffer.length > 0) {
+    return new Error('unrecognised content at end of stream');
+  }
+
+};

test/list.html

@@ -11,175 +11,175 @@
 <body>
 
 <h3>Filtering</h3>
-<img src="in/f99n0g04.png"> <img src="out/f99n0g04.png"> filter changing per scanline, grayscale, 4 bit <br />
-<img src="in/f04n2c08.png"> <img src="out/f04n2c08.png"> no filtering, colour, 8 bit <br />
-<img src="in/f04n0g08.png"> <img src="out/f04n0g08.png"> no filtering, grayscale, 8 bit<br />
-<img src="in/f03n2c08.png"> <img src="out/f03n2c08.png"> filter 3, colour, 8 bit <br />
-<img src="in/f03n0g08.png"> <img src="out/f03n0g08.png"> filter 3, grayscale, 8 bit<br />
-<img src="in/f02n2c08.png"> <img src="out/f02n2c08.png"> filter 2, colour, 8 bit <br />
-<img src="in/f02n0g08.png"> <img src="out/f02n0g08.png"> filter 2, grayscale, 8 bit<br />
-<img src="in/f01n2c08.png"> <img src="out/f01n2c08.png"> filter 1, colour, 8 bit <br />
-<img src="in/f01n0g08.png"> <img src="out/f01n0g08.png"> filter 1, grayscale, 8 bit<br />
-<img src="in/f00n2c08.png"> <img src="out/f00n2c08.png"> filter 0, colour, 8 bit <br />
-<img src="in/f00n0g08.png"> <img src="out/f00n0g08.png"> filter 0, grayscale, 8 bit<br />
+<img src="in/f99n0g04.png"> <img src="out/f99n0g04.png"> <img src="outsync/f99n0g04.png"> filter changing per scanline, grayscale, 4 bit <br />
+<img src="in/f04n2c08.png"> <img src="out/f04n2c08.png"> <img src="outsync/f04n2c08.png"> no filtering, colour, 8 bit <br />
+<img src="in/f04n0g08.png"> <img src="out/f04n0g08.png"> <img src="outsync/f04n0g08.png"> no filtering, grayscale, 8 bit<br />
+<img src="in/f03n2c08.png"> <img src="out/f03n2c08.png"> <img src="outsync/f03n2c08.png"> filter 3, colour, 8 bit <br />
+<img src="in/f03n0g08.png"> <img src="out/f03n0g08.png"> <img src="outsync/f03n0g08.png"> filter 3, grayscale, 8 bit<br />
+<img src="in/f02n2c08.png"> <img src="out/f02n2c08.png"> <img src="outsync/f02n2c08.png"> filter 2, colour, 8 bit <br />
+<img src="in/f02n0g08.png"> <img src="out/f02n0g08.png"> <img src="outsync/f02n0g08.png"> filter 2, grayscale, 8 bit<br />
+<img src="in/f01n2c08.png"> <img src="out/f01n2c08.png"> <img src="outsync/f01n2c08.png"> filter 1, colour, 8 bit <br />
+<img src="in/f01n0g08.png"> <img src="out/f01n0g08.png"> <img src="outsync/f01n0g08.png"> filter 1, grayscale, 8 bit<br />
+<img src="in/f00n2c08.png"> <img src="out/f00n2c08.png"> <img src="outsync/f00n2c08.png"> filter 0, colour, 8 bit <br />
+<img src="in/f00n0g08.png"> <img src="out/f00n0g08.png"> <img src="outsync/f00n0g08.png"> filter 0, grayscale, 8 bit<br />
 <h3>Ancilary chunks</h3>
-<img src="in/ctzn0g04.png"> <img src="out/ctzn0g04.png"> <br />
-<img src="in/ctjn0g04.png"> <img src="out/ctjn0g04.png"> <br />
-<img src="in/cthn0g04.png"> <img src="out/cthn0g04.png"> <br />
-<img src="in/ctgn0g04.png"> <img src="out/ctgn0g04.png"> <br />
-<img src="in/ctfn0g04.png"> <img src="out/ctfn0g04.png"> <br />
-<img src="in/cten0g04.png"> <img src="out/cten0g04.png"> <br />
-<img src="in/ct1n0g04.png"> <img src="out/ct1n0g04.png"> <br />
-<img src="in/ct0n0g04.png"> <img src="out/ct0n0g04.png"> <br />
-<img src="in/cs8n3p08.png"> <img src="out/cs8n3p08.png"> <br />
-<img src="in/cs8n2c08.png"> <img src="out/cs8n2c08.png"> <br />
-<img src="in/cs5n3p08.png"> <img src="out/cs5n3p08.png"> <br />
-<img src="in/cs5n2c08.png"> <img src="out/cs5n2c08.png"> <br />
-<img src="in/cs3n3p08.png"> <img src="out/cs3n3p08.png"> <br />
-<img src="in/cs3n2c16.png"> <img src="out/cs3n2c16.png"> <br />
-<img src="in/cm9n0g04.png"> <img src="out/cm9n0g04.png"> <br />
-<img src="in/cm7n0g04.png"> <img src="out/cm7n0g04.png"> <br />
-<img src="in/cm0n0g04.png"> <img src="out/cm0n0g04.png"> <br />
-<img src="in/ch2n3p08.png"> <img src="out/ch2n3p08.png"> <br />
-<img src="in/ch1n3p04.png"> <img src="out/ch1n3p04.png"> <br />
-<img src="in/cdun2c08.png"> <img src="out/cdun2c08.png"> <br />
-<img src="in/cdsn2c08.png"> <img src="out/cdsn2c08.png"> <br />
-<img src="in/cdhn2c08.png"> <img src="out/cdhn2c08.png"> <br />
-<img src="in/cdfn2c08.png"> <img src="out/cdfn2c08.png"> <br />
-<img src="in/ccwn3p08.png"> <img src="out/ccwn3p08.png"> <br />
-<img src="in/ccwn2c08.png"> <img src="out/ccwn2c08.png"> <br />
+<img src="in/ctzn0g04.png"> <img src="out/ctzn0g04.png"> <img src="outsync/ctzn0g04.png"> <br />
+<img src="in/ctjn0g04.png"> <img src="out/ctjn0g04.png"> <img src="outsync/ctjn0g04.png"> <br />
+<img src="in/cthn0g04.png"> <img src="out/cthn0g04.png"> <img src="outsync/cthn0g04.png"> <br />
+<img src="in/ctgn0g04.png"> <img src="out/ctgn0g04.png"> <img src="outsync/ctgn0g04.png"> <br />
+<img src="in/ctfn0g04.png"> <img src="out/ctfn0g04.png"> <img src="outsync/ctfn0g04.png"> <br />
+<img src="in/cten0g04.png"> <img src="out/cten0g04.png"> <img src="outsync/cten0g04.png"> <br />
+<img src="in/ct1n0g04.png"> <img src="out/ct1n0g04.png"> <img src="outsync/ct1n0g04.png"> <br />
+<img src="in/ct0n0g04.png"> <img src="out/ct0n0g04.png"> <img src="outsync/ct0n0g04.png"> <br />
+<img src="in/cs8n3p08.png"> <img src="out/cs8n3p08.png"> <img src="outsync/cs8n3p08.png"> <br />
+<img src="in/cs8n2c08.png"> <img src="out/cs8n2c08.png"> <img src="outsync/cs8n2c08.png"> <br />
+<img src="in/cs5n3p08.png"> <img src="out/cs5n3p08.png"> <img src="outsync/cs5n3p08.png"> <br />
+<img src="in/cs5n2c08.png"> <img src="out/cs5n2c08.png"> <img src="outsync/cs5n2c08.png"> <br />
+<img src="in/cs3n3p08.png"> <img src="out/cs3n3p08.png"> <img src="outsync/cs3n3p08.png"> <br />
+<img src="in/cs3n2c16.png"> <img src="out/cs3n2c16.png"> <img src="outsync/cs3n2c16.png"> <br />
+<img src="in/cm9n0g04.png"> <img src="out/cm9n0g04.png"> <img src="outsync/cm9n0g04.png"> <br />
+<img src="in/cm7n0g04.png"> <img src="out/cm7n0g04.png"> <img src="outsync/cm7n0g04.png"> <br />
+<img src="in/cm0n0g04.png"> <img src="out/cm0n0g04.png"> <img src="outsync/cm0n0g04.png"> <br />
+<img src="in/ch2n3p08.png"> <img src="out/ch2n3p08.png"> <img src="outsync/ch2n3p08.png"> <br />
+<img src="in/ch1n3p04.png"> <img src="out/ch1n3p04.png"> <img src="outsync/ch1n3p04.png"> <br />
+<img src="in/cdun2c08.png"> <img src="out/cdun2c08.png"> <img src="outsync/cdun2c08.png"> <br />
+<img src="in/cdsn2c08.png"> <img src="out/cdsn2c08.png"> <img src="outsync/cdsn2c08.png"> <br />
+<img src="in/cdhn2c08.png"> <img src="out/cdhn2c08.png"> <img src="outsync/cdhn2c08.png"> <br />
+<img src="in/cdfn2c08.png"> <img src="out/cdfn2c08.png"> <img src="outsync/cdfn2c08.png"> <br />
+<img src="in/ccwn3p08.png"> <img src="out/ccwn3p08.png"> <img src="outsync/ccwn3p08.png"> <br />
+<img src="in/ccwn2c08.png"> <img src="out/ccwn2c08.png"> <img src="outsync/ccwn2c08.png"> <br />
 
 <h3>Basic</h3>
-<img src="in/basi0g08.png"> <img src="out/basi0g08.png"> <br />
-<img src="in/basi0g04.png"> <img src="out/basi0g04.png"> <br />
-<img src="in/basi0g02.png"> <img src="out/basi0g02.png"> <br />
-<img src="in/basi0g01.png"> <img src="out/basi0g01.png"> <br />
-<img src="in/bgyn6a16.png"> <img src="out/bgyn6a16.png"> <br />
-<img src="in/bgwn6a08.png"> <img src="out/bgwn6a08.png"> <br />
-<img src="in/bggn4a16.png"> <img src="out/bggn4a16.png"> <br />
-<img src="in/bgbn4a08.png"> <img src="out/bgbn4a08.png"> <br />
-<img src="in/bgan6a16.png"> <img src="out/bgan6a16.png"> <br />
-<img src="in/bgan6a08.png"> <img src="out/bgan6a08.png"> <br />
-<img src="in/bgai4a16.png"> <img src="out/bgai4a16.png"> <br />
-<img src="in/bgai4a08.png"> <img src="out/bgai4a08.png"> <br />
-<img src="in/basn6a16.png"> <img src="out/basn6a16.png"> <br />
-<img src="in/basn6a08.png"> <img src="out/basn6a08.png"> <br />
-<img src="in/basn4a16.png"> <img src="out/basn4a16.png"> <br />
-<img src="in/basn4a08.png"> <img src="out/basn4a08.png"> <br />
-<img src="in/basn3p08.png"> <img src="out/basn3p08.png"> <br />
-<img src="in/basn3p04.png"> <img src="out/basn3p04.png"> <br />
-<img src="in/basn3p02.png"> <img src="out/basn3p02.png"> <br />
-<img src="in/basn3p01.png"> <img src="out/basn3p01.png"> <br />
-<img src="in/basn2c16.png"> <img src="out/basn2c16.png"> <br />
-<img src="in/basn2c08.png"> <img src="out/basn2c08.png"> <br />
-<img src="in/basn0g16.png"> <img src="out/basn0g16.png"> <br />
-<img src="in/basn0g08.png"> <img src="out/basn0g08.png"> <br />
-<img src="in/basn0g04.png"> <img src="out/basn0g04.png"> <br />
-<img src="in/basn0g02.png"> <img src="out/basn0g02.png"> <br />
-<img src="in/basn0g01.png"> <img src="out/basn0g01.png"> <br />
-<img src="in/basi6a16.png"> <img src="out/basi6a16.png"> <br />
-<img src="in/basi6a08.png"> <img src="out/basi6a08.png"> <br />
-<img src="in/basi4a16.png"> <img src="out/basi4a16.png"> <br />
-<img src="in/basi4a08.png"> <img src="out/basi4a08.png"> <br />
-<img src="in/basi3p08.png"> <img src="out/basi3p08.png"> <br />
-<img src="in/basi3p04.png"> <img src="out/basi3p04.png"> <br />
-<img src="in/basi3p02.png"> <img src="out/basi3p02.png"> <br />
-<img src="in/basi3p01.png"> <img src="out/basi3p01.png"> <br />
-<img src="in/basi2c16.png"> <img src="out/basi2c16.png"> <br />
-<img src="in/basi2c08.png"> <img src="out/basi2c08.png"> <br />
-<img src="in/basi0g16.png"> <img src="out/basi0g16.png"> <br />
+<img src="in/basi0g08.png"> <img src="out/basi0g08.png"> <img src="outsync/basi0g08.png"> <br />
+<img src="in/basi0g04.png"> <img src="out/basi0g04.png"> <img src="outsync/basi0g04.png"> <br />
+<img src="in/basi0g02.png"> <img src="out/basi0g02.png"> <img src="outsync/basi0g02.png"> <br />
+<img src="in/basi0g01.png"> <img src="out/basi0g01.png"> <img src="outsync/basi0g01.png"> <br />
+<img src="in/bgyn6a16.png"> <img src="out/bgyn6a16.png"> <img src="outsync/bgyn6a16.png"> <br />
+<img src="in/bgwn6a08.png"> <img src="out/bgwn6a08.png"> <img src="outsync/bgwn6a08.png"> <br />
+<img src="in/bggn4a16.png"> <img src="out/bggn4a16.png"> <img src="outsync/bggn4a16.png"> <br />
+<img src="in/bgbn4a08.png"> <img src="out/bgbn4a08.png"> <img src="outsync/bgbn4a08.png"> <br />
+<img src="in/bgan6a16.png"> <img src="out/bgan6a16.png"> <img src="outsync/bgan6a16.png"> <br />
+<img src="in/bgan6a08.png"> <img src="out/bgan6a08.png"> <img src="outsync/bgan6a08.png"> <br />
+<img src="in/bgai4a16.png"> <img src="out/bgai4a16.png"> <img src="outsync/bgai4a16.png"> <br />
+<img src="in/bgai4a08.png"> <img src="out/bgai4a08.png"> <img src="outsync/bgai4a08.png"> <br />
+<img src="in/basn6a16.png"> <img src="out/basn6a16.png"> <img src="outsync/basn6a16.png"> <br />
+<img src="in/basn6a08.png"> <img src="out/basn6a08.png"> <img src="outsync/basn6a08.png"> <br />
+<img src="in/basn4a16.png"> <img src="out/basn4a16.png"> <img src="outsync/basn4a16.png"> <br />
+<img src="in/basn4a08.png"> <img src="out/basn4a08.png"> <img src="outsync/basn4a08.png"> <br />
+<img src="in/basn3p08.png"> <img src="out/basn3p08.png"> <img src="outsync/basn3p08.png"> <br />
+<img src="in/basn3p04.png"> <img src="out/basn3p04.png"> <img src="outsync/basn3p04.png"> <br />
+<img src="in/basn3p02.png"> <img src="out/basn3p02.png"> <img src="outsync/basn3p02.png"> <br />
+<img src="in/basn3p01.png"> <img src="out/basn3p01.png"> <img src="outsync/basn3p01.png"> <br />
+<img src="in/basn2c16.png"> <img src="out/basn2c16.png"> <img src="outsync/basn2c16.png"> <br />
+<img src="in/basn2c08.png"> <img src="out/basn2c08.png"> <img src="outsync/basn2c08.png"> <br />
+<img src="in/basn0g16.png"> <img src="out/basn0g16.png"> <img src="outsync/basn0g16.png"> <br />
+<img src="in/basn0g08.png"> <img src="out/basn0g08.png"> <img src="outsync/basn0g08.png"> <br />
+<img src="in/basn0g04.png"> <img src="out/basn0g04.png"> <img src="outsync/basn0g04.png"> <br />
+<img src="in/basn0g02.png"> <img src="out/basn0g02.png"> <img src="outsync/basn0g02.png"> <br />
+<img src="in/basn0g01.png"> <img src="out/basn0g01.png"> <img src="outsync/basn0g01.png"> <br />
+<img src="in/basi6a16.png"> <img src="out/basi6a16.png"> <img src="outsync/basi6a16.png"> <br />
+<img src="in/basi6a08.png"> <img src="out/basi6a08.png"> <img src="outsync/basi6a08.png"> <br />
+<img src="in/basi4a16.png"> <img src="out/basi4a16.png"> <img src="outsync/basi4a16.png"> <br />
+<img src="in/basi4a08.png"> <img src="out/basi4a08.png"> <img src="outsync/basi4a08.png"> <br />
+<img src="in/basi3p08.png"> <img src="out/basi3p08.png"> <img src="outsync/basi3p08.png"> <br />
+<img src="in/basi3p04.png"> <img src="out/basi3p04.png"> <img src="outsync/basi3p04.png"> <br />
+<img src="in/basi3p02.png"> <img src="out/basi3p02.png"> <img src="outsync/basi3p02.png"> <br />
+<img src="in/basi3p01.png"> <img src="out/basi3p01.png"> <img src="outsync/basi3p01.png"> <br />
+<img src="in/basi2c16.png"> <img src="out/basi2c16.png"> <img src="outsync/basi2c16.png"> <br />
+<img src="in/basi2c08.png"> <img src="out/basi2c08.png"> <img src="outsync/basi2c08.png"> <br />
+<img src="in/basi0g16.png"> <img src="out/basi0g16.png"> <img src="outsync/basi0g16.png"> <br />
 <h3>ZLib</h3>
-<img src="in/z09n2c08.png"> <img src="out/z09n2c08.png"> <br />
-<img src="in/z06n2c08.png"> <img src="out/z06n2c08.png"> <br />
-<img src="in/z03n2c08.png"> <img src="out/z03n2c08.png"> <br />
-<img src="in/z00n2c08.png"> <img src="out/z00n2c08.png"> <br />
+<img src="in/z09n2c08.png"> <img src="out/z09n2c08.png"> <img src="outsync/z09n2c08.png"> <br />
+<img src="in/z06n2c08.png"> <img src="out/z06n2c08.png"> <img src="outsync/z06n2c08.png"> <br />
+<img src="in/z03n2c08.png"> <img src="out/z03n2c08.png"> <img src="outsync/z03n2c08.png"> <br />
+<img src="in/z00n2c08.png"> <img src="out/z00n2c08.png"> <img src="outsync/z00n2c08.png"> <br />
 <h3>Transparency</h3>
-<img src="in/tp1n3p08.png"> <img src="out/tp1n3p08.png"> <br />
-<img src="in/tp0n3p08.png"> <img src="out/tp0n3p08.png"> <br />
-<img src="in/tp0n2c08.png"> <img src="out/tp0n2c08.png"> <br />
-<img src="in/tp0n0g08.png"> <img src="out/tp0n0g08.png"> <br />
-<img src="in/tm3n3p02.png"> <img src="out/tm3n3p02.png"> <br />
-<img src="in/tbyn3p08.png"> <img src="out/tbyn3p08.png"> <br />
-<img src="in/tbwn3p08.png"> <img src="out/tbwn3p08.png"> <br />
-<img src="in/tbwn0g16.png"> <img src="out/tbwn0g16.png"> <br />
-<img src="in/tbrn2c08.png"> <img src="out/tbrn2c08.png"> <br />
-<img src="in/tbgn3p08.png"> <img src="out/tbgn3p08.png"> <br />
-<img src="in/tbgn2c16.png"> <img src="out/tbgn2c16.png"> <br />
-<img src="in/tbbn3p08.png"> <img src="out/tbbn3p08.png"> <br />
-<img src="in/tbbn2c16.png"> <img src="out/tbbn2c16.png"> <br />
-<img src="in/tbbn0g04.png"> <img src="out/tbbn0g04.png"> <br />
+<img src="in/tp1n3p08.png"> <img src="out/tp1n3p08.png"> <img src="outsync/tp1n3p08.png"> <br />
+<img src="in/tp0n3p08.png"> <img src="out/tp0n3p08.png"> <img src="outsync/tp0n3p08.png"> <br />
+<img src="in/tp0n2c08.png"> <img src="out/tp0n2c08.png"> <img src="outsync/tp0n2c08.png"> <br />
+<img src="in/tp0n0g08.png"> <img src="out/tp0n0g08.png"> <img src="outsync/tp0n0g08.png"> <br />
+<img src="in/tm3n3p02.png"> <img src="out/tm3n3p02.png"> <img src="outsync/tm3n3p02.png"> <br />
+<img src="in/tbyn3p08.png"> <img src="out/tbyn3p08.png"> <img src="outsync/tbyn3p08.png"> <br />
+<img src="in/tbwn3p08.png"> <img src="out/tbwn3p08.png"> <img src="outsync/tbwn3p08.png"> <br />
+<img src="in/tbwn0g16.png"> <img src="out/tbwn0g16.png"> <img src="outsync/tbwn0g16.png"> <br />
+<img src="in/tbrn2c08.png"> <img src="out/tbrn2c08.png"> <img src="outsync/tbrn2c08.png"> <br />
+<img src="in/tbgn3p08.png"> <img src="out/tbgn3p08.png"> <img src="outsync/tbgn3p08.png"> <br />
+<img src="in/tbgn2c16.png"> <img src="out/tbgn2c16.png"> <img src="outsync/tbgn2c16.png"> <br />
+<img src="in/tbbn3p08.png"> <img src="out/tbbn3p08.png"> <img src="outsync/tbbn3p08.png"> <br />
+<img src="in/tbbn2c16.png"> <img src="out/tbbn2c16.png"> <img src="outsync/tbbn2c16.png"> <br />
+<img src="in/tbbn0g04.png"> <img src="out/tbbn0g04.png"> <img src="outsync/tbbn0g04.png"> <br />
 <h3>Sizing</h3>
-<img src="in/s40n3p04.png"> <img src="out/s40n3p04.png"> <br />
-<img src="in/s40i3p04.png"> <img src="out/s40i3p04.png"> <br />
-<img src="in/s39n3p04.png"> <img src="out/s39n3p04.png"> <br />
-<img src="in/s39i3p04.png"> <img src="out/s39i3p04.png"> <br />
-<img src="in/s38n3p04.png"> <img src="out/s38n3p04.png"> <br />
-<img src="in/s38i3p04.png"> <img src="out/s38i3p04.png"> <br />
-<img src="in/s37n3p04.png"> <img src="out/s37n3p04.png"> <br />
-<img src="in/s37i3p04.png"> <img src="out/s37i3p04.png"> <br />
-<img src="in/s36n3p04.png"> <img src="out/s36n3p04.png"> <br />
-<img src="in/s36i3p04.png"> <img src="out/s36i3p04.png"> <br />
-<img src="in/s35n3p04.png"> <img src="out/s35n3p04.png"> <br />
-<img src="in/s35i3p04.png"> <img src="out/s35i3p04.png"> <br />
-<img src="in/s34n3p04.png"> <img src="out/s34n3p04.png"> <br />
-<img src="in/s34i3p04.png"> <img src="out/s34i3p04.png"> <br />
-<img src="in/s33n3p04.png"> <img src="out/s33n3p04.png"> <br />
-<img src="in/s33i3p04.png"> <img src="out/s33i3p04.png"> <br />
-<img src="in/s32n3p04.png"> <img src="out/s32n3p04.png"> <br />
-<img src="in/s32i3p04.png"> <img src="out/s32i3p04.png"> <br />
-<img src="in/s09n3p02.png"> <img src="out/s09n3p02.png"> <br />
-<img src="in/s09i3p02.png"> <img src="out/s09i3p02.png"> <br />
-<img src="in/s08n3p02.png"> <img src="out/s08n3p02.png"> <br />
-<img src="in/s08i3p02.png"> <img src="out/s08i3p02.png"> <br />
-<img src="in/s07n3p02.png"> <img src="out/s07n3p02.png"> <br />
-<img src="in/s07i3p02.png"> <img src="out/s07i3p02.png"> <br />
-<img src="in/s06n3p02.png"> <img src="out/s06n3p02.png"> <br />
-<img src="in/s06i3p02.png"> <img src="out/s06i3p02.png"> <br />
-<img src="in/s05n3p02.png"> <img src="out/s05n3p02.png"> <br />
-<img src="in/s05i3p02.png"> <img src="out/s05i3p02.png"> <br />
-<img src="in/s04n3p01.png"> <img src="out/s04n3p01.png"> <br />
-<img src="in/s04i3p01.png"> <img src="out/s04i3p01.png"> <br />
-<img src="in/s03n3p01.png"> <img src="out/s03n3p01.png"> <br />
-<img src="in/s03i3p01.png"> <img src="out/s03i3p01.png"> <br />
-<img src="in/s02n3p01.png"> <img src="out/s02n3p01.png"> <br />
-<img src="in/s02i3p01.png"> <img src="out/s02i3p01.png"> <br />
-<img src="in/s01n3p01.png"> <img src="out/s01n3p01.png"> <br />
-<img src="in/s01i3p01.png"> <img src="out/s01i3p01.png"> <br />
+<img src="in/s40n3p04.png"> <img src="out/s40n3p04.png"> <img src="outsync/s40n3p04.png"> <br />
+<img src="in/s40i3p04.png"> <img src="out/s40i3p04.png"> <img src="outsync/s40i3p04.png"> <br />
+<img src="in/s39n3p04.png"> <img src="out/s39n3p04.png"> <img src="outsync/s39n3p04.png"> <br />
+<img src="in/s39i3p04.png"> <img src="out/s39i3p04.png"> <img src="outsync/s39i3p04.png"> <br />
+<img src="in/s38n3p04.png"> <img src="out/s38n3p04.png"> <img src="outsync/s38n3p04.png"> <br />
+<img src="in/s38i3p04.png"> <img src="out/s38i3p04.png"> <img src="outsync/s38i3p04.png"> <br />
+<img src="in/s37n3p04.png"> <img src="out/s37n3p04.png"> <img src="outsync/s37n3p04.png"> <br />
+<img src="in/s37i3p04.png"> <img src="out/s37i3p04.png"> <img src="outsync/s37i3p04.png"> <br />
+<img src="in/s36n3p04.png"> <img src="out/s36n3p04.png"> <img src="outsync/s36n3p04.png"> <br />
+<img src="in/s36i3p04.png"> <img src="out/s36i3p04.png"> <img src="outsync/s36i3p04.png"> <br />
+<img src="in/s35n3p04.png"> <img src="out/s35n3p04.png"> <img src="outsync/s35n3p04.png"> <br />
+<img src="in/s35i3p04.png"> <img src="out/s35i3p04.png"> <img src="outsync/s35i3p04.png"> <br />
+<img src="in/s34n3p04.png"> <img src="out/s34n3p04.png"> <img src="outsync/s34n3p04.png"> <br />
+<img src="in/s34i3p04.png"> <img src="out/s34i3p04.png"> <img src="outsync/s34i3p04.png"> <br />
+<img src="in/s33n3p04.png"> <img src="out/s33n3p04.png"> <img src="outsync/s33n3p04.png"> <br />
+<img src="in/s33i3p04.png"> <img src="out/s33i3p04.png"> <img src="outsync/s33i3p04.png"> <br />
+<img src="in/s32n3p04.png"> <img src="out/s32n3p04.png"> <img src="outsync/s32n3p04.png"> <br />
+<img src="in/s32i3p04.png"> <img src="out/s32i3p04.png"> <img src="outsync/s32i3p04.png"> <br />
+<img src="in/s09n3p02.png"> <img src="out/s09n3p02.png"> <img src="outsync/s09n3p02.png"> <br />
+<img src="in/s09i3p02.png"> <img src="out/s09i3p02.png"> <img src="outsync/s09i3p02.png"> <br />
+<img src="in/s08n3p02.png"> <img src="out/s08n3p02.png"> <img src="outsync/s08n3p02.png"> <br />
+<img src="in/s08i3p02.png"> <img src="out/s08i3p02.png"> <img src="outsync/s08i3p02.png"> <br />
+<img src="in/s07n3p02.png"> <img src="out/s07n3p02.png"> <img src="outsync/s07n3p02.png"> <br />
+<img src="in/s07i3p02.png"> <img src="out/s07i3p02.png"> <img src="outsync/s07i3p02.png"> <br />
+<img src="in/s06n3p02.png"> <img src="out/s06n3p02.png"> <img src="outsync/s06n3p02.png"> <br />
+<img src="in/s06i3p02.png"> <img src="out/s06i3p02.png"> <img src="outsync/s06i3p02.png"> <br />
+<img src="in/s05n3p02.png"> <img src="out/s05n3p02.png"> <img src="outsync/s05n3p02.png"> <br />
+<img src="in/s05i3p02.png"> <img src="out/s05i3p02.png"> <img src="outsync/s05i3p02.png"> <br />
+<img src="in/s04n3p01.png"> <img src="out/s04n3p01.png"> <img src="outsync/s04n3p01.png"> <br />
+<img src="in/s04i3p01.png"> <img src="out/s04i3p01.png"> <img src="outsync/s04i3p01.png"> <br />
+<img src="in/s03n3p01.png"> <img src="out/s03n3p01.png"> <img src="outsync/s03n3p01.png"> <br />
+<img src="in/s03i3p01.png"> <img src="out/s03i3p01.png"> <img src="outsync/s03i3p01.png"> <br />
+<img src="in/s02n3p01.png"> <img src="out/s02n3p01.png"> <img src="outsync/s02n3p01.png"> <br />
+<img src="in/s02i3p01.png"> <img src="out/s02i3p01.png"> <img src="outsync/s02i3p01.png"> <br />
+<img src="in/s01n3p01.png"> <img src="out/s01n3p01.png"> <img src="outsync/s01n3p01.png"> <br />
+<img src="in/s01i3p01.png"> <img src="out/s01i3p01.png"> <img src="outsync/s01i3p01.png"> <br />
 <h3>Pallettes</h3>
-<img src="in/ps2n2c16.png"> <img src="out/ps2n2c16.png"> <br />
-<img src="in/ps2n0g08.png"> <img src="out/ps2n0g08.png"> <br />
-<img src="in/ps1n2c16.png"> <img src="out/ps1n2c16.png"> <br />
-<img src="in/ps1n0g08.png"> <img src="out/ps1n0g08.png"> <br />
-<img src="in/pp0n6a08.png"> <img src="out/pp0n6a08.png"> <br />
-<img src="in/pp0n2c16.png"> <img src="out/pp0n2c16.png"> <br />
+<img src="in/ps2n2c16.png"> <img src="out/ps2n2c16.png"> <img src="outsync/ps2n2c16.png"> <br />
+<img src="in/ps2n0g08.png"> <img src="out/ps2n0g08.png"> <img src="outsync/ps2n0g08.png"> <br />
+<img src="in/ps1n2c16.png"> <img src="out/ps1n2c16.png"> <img src="outsync/ps1n2c16.png"> <br />
+<img src="in/ps1n0g08.png"> <img src="out/ps1n0g08.png"> <img src="outsync/ps1n0g08.png"> <br />
+<img src="in/pp0n6a08.png"> <img src="out/pp0n6a08.png"> <img src="outsync/pp0n6a08.png"> <br />
+<img src="in/pp0n2c16.png"> <img src="out/pp0n2c16.png"> <img src="outsync/pp0n2c16.png"> <br />
 <h3>Chunk Ordering</h3>
-<img src="in/oi9n2c16.png"> <img src="out/oi9n2c16.png"> <br />
-<img src="in/oi9n0g16.png"> <img src="out/oi9n0g16.png"> <br />
-<img src="in/oi4n2c16.png"> <img src="out/oi4n2c16.png"> <br />
-<img src="in/oi4n0g16.png"> <img src="out/oi4n0g16.png"> <br />
-<img src="in/oi2n2c16.png"> <img src="out/oi2n2c16.png"> <br />
-<img src="in/oi2n0g16.png"> <img src="out/oi2n0g16.png"> <br />
-<img src="in/oi1n2c16.png"> <img src="out/oi1n2c16.png"> <br />
-<img src="in/oi1n0g16.png"> <img src="out/oi1n0g16.png"> <br />
+<img src="in/oi9n2c16.png"> <img src="out/oi9n2c16.png"> <img src="outsync/oi9n2c16.png"> <br />
+<img src="in/oi9n0g16.png"> <img src="out/oi9n0g16.png"> <img src="outsync/oi9n0g16.png"> <br />
+<img src="in/oi4n2c16.png"> <img src="out/oi4n2c16.png"> <img src="outsync/oi4n2c16.png"> <br />
+<img src="in/oi4n0g16.png"> <img src="out/oi4n0g16.png"> <img src="outsync/oi4n0g16.png"> <br />
+<img src="in/oi2n2c16.png"> <img src="out/oi2n2c16.png"> <img src="outsync/oi2n2c16.png"> <br />
+<img src="in/oi2n0g16.png"> <img src="out/oi2n0g16.png"> <img src="outsync/oi2n0g16.png"> <br />
+<img src="in/oi1n2c16.png"> <img src="out/oi1n2c16.png"> <img src="outsync/oi1n2c16.png"> <br />
+<img src="in/oi1n0g16.png"> <img src="out/oi1n0g16.png"> <img src="outsync/oi1n0g16.png"> <br />
 <h3>Gamma</h3>
-<img src="in/g25n3p04.png"> <img src="out/g25n3p04.png"> <br />
-<img src="in/g25n2c08.png"> <img src="out/g25n2c08.png"> <br />
-<img src="in/g25n0g16.png"> <img src="out/g25n0g16.png"> <br />
-<img src="in/g10n3p04.png"> <img src="out/g10n3p04.png"> <br />
-<img src="in/g10n2c08.png"> <img src="out/g10n2c08.png"> <br />
-<img src="in/g10n0g16.png"> <img src="out/g10n0g16.png"> <br />
-<img src="in/g07n3p04.png"> <img src="out/g07n3p04.png"> <br />
-<img src="in/g07n2c08.png"> <img src="out/g07n2c08.png"> <br />
-<img src="in/g07n0g16.png"> <img src="out/g07n0g16.png"> <br />
-<img src="in/g05n3p04.png"> <img src="out/g05n3p04.png"> <br />
-<img src="in/g05n2c08.png"> <img src="out/g05n2c08.png"> <br />
-<img src="in/g05n0g16.png"> <img src="out/g05n0g16.png"> <br />
-<img src="in/g04n3p04.png"> <img src="out/g04n3p04.png"> <br />
-<img src="in/g04n2c08.png"> <img src="out/g04n2c08.png"> <br />
-<img src="in/g04n0g16.png"> <img src="out/g04n0g16.png"> <br />
-<img src="in/g03n3p04.png"> <img src="out/g03n3p04.png"> <br />
-<img src="in/g03n2c08.png"> <img src="out/g03n2c08.png"> <br />
-<img src="in/g03n0g16.png"> <img src="out/g03n0g16.png"> <br />
+<img src="in/g25n3p04.png"> <img src="out/g25n3p04.png"> <img src="outsync/g25n3p04.png"> <br />
+<img src="in/g25n2c08.png"> <img src="out/g25n2c08.png"> <img src="outsync/g25n2c08.png"> <br />
+<img src="in/g25n0g16.png"> <img src="out/g25n0g16.png"> <img src="outsync/g25n0g16.png"> <br />
+<img src="in/g10n3p04.png"> <img src="out/g10n3p04.png"> <img src="outsync/g10n3p04.png"> <br />
+<img src="in/g10n2c08.png"> <img src="out/g10n2c08.png"> <img src="outsync/g10n2c08.png"> <br />
+<img src="in/g10n0g16.png"> <img src="out/g10n0g16.png"> <img src="outsync/g10n0g16.png"> <br />
+<img src="in/g07n3p04.png"> <img src="out/g07n3p04.png"> <img src="outsync/g07n3p04.png"> <br />
+<img src="in/g07n2c08.png"> <img src="out/g07n2c08.png"> <img src="outsync/g07n2c08.png"> <br />
+<img src="in/g07n0g16.png"> <img src="out/g07n0g16.png"> <img src="outsync/g07n0g16.png"> <br />
+<img src="in/g05n3p04.png"> <img src="out/g05n3p04.png"> <img src="outsync/g05n3p04.png"> <br />
+<img src="in/g05n2c08.png"> <img src="out/g05n2c08.png"> <img src="outsync/g05n2c08.png"> <br />
+<img src="in/g05n0g16.png"> <img src="out/g05n0g16.png"> <img src="outsync/g05n0g16.png"> <br />
+<img src="in/g04n3p04.png"> <img src="out/g04n3p04.png"> <img src="outsync/g04n3p04.png"> <br />
+<img src="in/g04n2c08.png"> <img src="out/g04n2c08.png"> <img src="outsync/g04n2c08.png"> <br />
+<img src="in/g04n0g16.png"> <img src="out/g04n0g16.png"> <img src="outsync/g04n0g16.png"> <br />
+<img src="in/g03n3p04.png"> <img src="out/g03n3p04.png"> <img src="outsync/g03n3p04.png"> <br />
+<img src="in/g03n2c08.png"> <img src="out/g03n2c08.png"> <img src="outsync/g03n2c08.png"> <br />
+<img src="in/g03n0g16.png"> <img src="out/g03n0g16.png"> <img src="outsync/g03n0g16.png"> <br />
 
 
 </body>

test/outsync/.gitignore

@@ -0,0 +1 @@
+*.png

test/test.js

@@ -2,7 +2,6 @@
 var fs = require('fs'),
     PNG = require('../lib/png').PNG;
 
-
 fs.readdir(__dirname + '/in/', function(err, files) {
     if (err) throw err;
 
@@ -20,6 +19,19 @@ fs.readdir(__dirname + '/in/', function(err, files) {
             expectedError = true;
         }
 
+        if (!expectedError) {
+            var data = fs.readFileSync(__dirname + '/in/' + file);
+            var png = PNG.sync.read(data);
+
+            var outpng = new PNG();
+            PNG.adjustGamma(png);
+            outpng.data = png.data;
+            outpng.width = png.width;
+            outpng.height = png.height;
+            outpng.pack()
+              .pipe(fs.createWriteStream(__dirname + '/outsync/' + file));
+        }
+
         fs.createReadStream(__dirname + '/in/' + file)
             .pipe(new PNG())
             .on('error', function(err) {
@@ -33,22 +45,10 @@ fs.readdir(__dirname + '/in/', function(err, files) {
                     console.log("Error expected, parsed fine", file);
                 }
 
-                if (this.gamma) {
-                    for (var y = 0; y < this.height; y++) {
-                        for (var x = 0; x < this.width; x++) {
-                            var idx = (this.width * y + x) << 2;
-
-                            for (var i = 0; i < 3; i++) {
-                                var sample = this.data[idx + i] / 255;
-                                sample = Math.pow(sample, 1 / 2.2 / this.gamma);
-                                this.data[idx + i] = Math.round(sample * 255);
-                            }
-                        }
-                    }
-                }
+                this.adjustGamma();
 
                 this.pack()
-                    .pipe(fs.createWriteStream(__dirname + '/out/' + file));
+                  .pipe(fs.createWriteStream(__dirname + '/out/' + file));
 
             });