pngjs - npm Package Compare versions

Comparing version 0.1.0-alpha to 0.2.0-alpha

examples/test2.js

@@ -8,3 +8,3 @@ #!/usr/bin/env node
 var png = new PNG({
-        filterType: 4
+        filterType: -1
     }),
@@ -21,9 +21,6 @@ src = fs.createReadStream(process.argv[2]),
 
-            // invert color
-            png.data[idx] = 255 - png.data[idx];
-            png.data[idx+1] = 255 - png.data[idx+1];
-            png.data[idx+2] = 255 - png.data[idx+2];
+            if (Math.abs(png.data[idx] - png.data[idx+1]) <= 1
+                    && Math.abs(png.data[idx+1] - png.data[idx+2]) <= 1)
+                png.data[idx] = png.data[idx+1] = png.data[idx+2];
 
-            // and reduce opacity
-            png.data[idx+3] = png.data[idx+3] >> 1;
         }
@@ -30,0 +27,0 @@ }

lib/filter.js

@@ -58,6 +58,6 @@ // Copyright (c) 2012 Kuba Niegowski
 
-Filter.prototype.unfilter = function(rawData) {
+Filter.prototype.unfilter = function(rawData, Bpp) {
 
     var pxLineLength = this.width << 2,
-        rawLineLength = pxLineLength + 1,
+        rawLineLength = this.width * Bpp + 1,
         pxData = new Buffer(pxLineLength * this.height);
@@ -69,44 +69,98 @@
             pxRowPos = y * pxLineLength,
-            pxUpRowPos = pxRowPos - pxLineLength,
             filter = rawData[rawRowPos - 1];
 
+
         if (filter == 0) {
-            rawData.copy(pxData, pxRowPos, rawRowPos, rawRowPos + pxLineLength);
+            for (var x = 0; x < this.width; x++) {
+                var pxPos = pxRowPos + (x << 2),
+                    rawPos = rawRowPos + x * Bpp;
 
+                for (var i = 0; i < Bpp; i++)
+                    pxData[pxPos + i] = rawData[rawPos + i];
+            }
+
         } else if (filter == 1) {
-            for (var x = 0; x < pxLineLength; x++) {
+            for (var x = 0; x < this.width; x++) {
+                var pxPos = pxRowPos + (x << 2),
+                    rawPos = rawRowPos + x * Bpp;
 
-                var left = x >= 4 ? pxData[pxRowPos + x - 4] : 0;
-                pxData[pxRowPos + x] = rawData[rawRowPos + x] + left;
+                for (var i = 0; i < Bpp; i++) {
+                    var left = x > 0 ? pxData[pxPos + i - 4] : 0;
+                    pxData[pxPos + i] = rawData[rawPos + i] + left;
+                }
             }
 
         } else if (filter == 2) {
-            for (var x = 0; x < pxLineLength; x++) {
+            for (var x = 0; x < this.width; x++) {
+                var pxPos = pxRowPos + (x << 2),
+                    rawPos = rawRowPos + x * Bpp;
 
-                var up = y > 0 ? pxData[pxUpRowPos + x] : 0;
-                pxData[pxRowPos + x] = rawData[rawRowPos + x] + up;
+                for (var i = 0; i < Bpp; i++) {
+                    var up = y > 0 ? pxData[pxPos - pxLineLength + i] : 0;
+                    pxData[pxPos + i] = rawData[rawPos + i] + up;
+                }
             }
 
         } else if (filter == 3) {
-            for (var x = 0; x < pxLineLength; x++) {
+            for (var x = 0; x < this.width; x++) {
+                var pxPos = pxRowPos + (x << 2),
+                    rawPos = rawRowPos + x * Bpp;
 
-                var left = x >= 4 ? pxData[pxRowPos + x - 4] : 0,
-                    up = y > 0 ? pxData[pxUpRowPos + x] : 0;
+                for (var i = 0; i < Bpp; i++) {
+                    var left = x > 0 ? pxData[pxPos + i - 4] : 0,
+                        up = y > 0 ? pxData[pxPos - pxLineLength + i] : 0;
 
-                pxData[pxRowPos + x] = rawData[rawRowPos + x]
-                    + Math.floor((left + up) / 2);
+                    pxData[pxPos + i] = rawData[rawPos + i]
+                        + Math.floor((left + up) / 2);
+                }
             }
 
         } else if (filter == 4) {
-            for (var x = 0; x < pxLineLength; x++) {
+            for (var x = 0; x < this.width; x++) {
+                var pxPos = pxRowPos + (x << 2),
+                    rawPos = rawRowPos + x * Bpp;
 
-                var left = x >= 4 ? pxData[pxRowPos + x - 4] : 0,
-                    up = y > 0 ? pxData[pxUpRowPos + x] : 0,
-                    upLeft = x >= 4 && y > 0 ? pxData[pxUpRowPos + x - 4] : 0;
+                for (var i = 0; i < Bpp; i++) {
+                    var left = x > 0 ? pxData[pxPos + i - 4] : 0,
+                        up = y > 0 ? pxData[pxPos - pxLineLength + i] : 0,
+                        upLeft = x > 0 && y > 0
+                                ? pxData[pxPos - pxLineLength + i - 4] : 0;
 
-                pxData[pxRowPos + x] = rawData[rawRowPos + x]
-                    + PaethPredictor(left, up, upLeft)
+                    pxData[pxPos + i] = rawData[rawPos + i]
+                        + PaethPredictor(left, up, upLeft)
+                }
             }
         }
     }
+
+    // expand data to 32 bit
+    for (var y = 0; y < this.height; y++) {
+        var pxRowPos = y * pxLineLength;
+
+        if (Bpp == 1) { // L
+            for (var x = 0; x < this.width; x++) {
+                var pxPos = pxRowPos + (x << 2);
+
+                pxData[pxPos + 1] = pxData[pxPos + 2] = pxData[pxPos];
+                pxData[pxPos + 3] = 0xff;
+            }
+
+        } else if (Bpp == 2) { // LA
+            for (var x = 0; x < this.width; x++) {
+                var pxPos = pxRowPos + (x << 2);
+
+                pxData[pxPos + 3] = pxData[pxPos + 1];
+                pxData[pxPos + 1] = pxData[pxPos + 2] = pxData[pxPos];
+            }
+
+        } else if (Bpp == 3) { // RGB
+            for (var x = 0; x < this.width; x++) {
+                var pxPos = pxRowPos + (x << 2);
+
+                pxData[pxPos + 3] = 0xff;
+            }
+
+        } // else RGBA
+    }
+
     return pxData;
@@ -151,3 +205,3 @@ };
         for (var x = 0; x < pxRowLength; x++)
-            sum += pxData[y * pxRowLength + x];
+            sum += Math.abs(pxData[y * pxRowLength + x]);
 
@@ -176,3 +230,3 @@ } else {
 
-        if (!rawData) sum += val;
+        if (!rawData) sum += Math.abs(val);
         else rawData[y * rawRowLength + 1 + x] = val;
@@ -197,3 +251,3 @@ }
 
-        if (!rawData) sum += val;
+        if (!rawData) sum += Math.abs(val);
         else rawData[y * rawRowLength + 1 + x] = val;
@@ -219,3 +273,3 @@ }
 
-        if (!rawData) sum += val;
+        if (!rawData) sum += Math.abs(val);
         else rawData[y * rawRowLength + 1 + x] = val;
@@ -242,3 +296,3 @@ }
 
-        if (!rawData) sum += val;
+        if (!rawData) sum += Math.abs(val);
         else rawData[y * rawRowLength + 1 + x] = val;
@@ -245,0 +299,0 @@ }

lib/parser.js

@@ -35,4 +35,11 @@ // Copyright (c) 2012 Kuba Niegowski
 var TYPE_IDAT = 0x49444154;
+var TYPE_PLTE = 0x504c5445;
+var TYPE_tRNS = 0x74524e53;
+var TYPE_gAMA = 0x67414d41;
 
+var COLOR_PALETTE = 1;
+var COLOR_COLOR = 2;
+var COLOR_ALPHA = 4;
 
+
 var Parser = module.exports = function(options) {
@@ -47,2 +54,6 @@ Stream.call(this);
 
+    // input flags
+    this._palette = [];
+    this._colorType = 0;
+
     this._chunks = {};
@@ -52,2 +63,5 @@ this._chunks[TYPE_IHDR] = this._parseIHDR.bind(this);
     this._chunks[TYPE_IDAT] = this._parseIDAT.bind(this);
+    this._chunks[TYPE_PLTE] = this._parsePLTE.bind(this);
+    this._chunks[TYPE_tRNS] = this._parseTRNS.bind(this);
+    this._chunks[TYPE_gAMA] = this._parseGAMA.bind(this);
 
@@ -66,5 +80,3 @@ this._compress = new Compress(options);
     this._compress.on('deflated', this._packData.bind(this));
-    this._compress.on('inflated', function(data) {
-        this.emit('parsed', this._filter.unfilter(data));
-    }.bind(this));
+    this._compress.on('inflated', this._unfilter.bind(this));
 };
@@ -118,2 +130,43 @@
 
+Parser.prototype._unfilter = function(data) {
+
+    // expand data to 32 bit depending on colorType
+    if (this._colorType == 0) { // L
+        data = this._filter.unfilter(data, 1); // 1 Bpp
+
+    } else if (this._colorType == 2) { // RGB
+        data = this._filter.unfilter(data, 3); // 3 Bpp
+
+    } else if (this._colorType == 3) { // I
+        data = this._filter.unfilter(data, 1); // 1 Bpp
+
+        // use values fom palette
+        var pxLineLength = this.width << 2;
+
+        for (var y = 0; y < this.height; y++) {
+            var pxRowPos = y * pxLineLength;
+
+            for (var x = 0; x < this.width; x++) {
+                var pxPos = pxRowPos + (x << 2),
+                    color = this._palette[data[pxPos]];
+
+                for (var i = 0; i < 4; i++)
+                    data[pxPos + i] = color[i];
+            }
+        }
+
+    } else if (this._colorType == 4) { // LA
+        data = this._filter.unfilter(data, 2); // 2 Bpp
+
+    } else if (this._colorType == 6) { // RGBA
+        data = this._filter.unfilter(data, 4); // 4 Bpp
+
+    } else throw new Error('Unsupported color type');
+
+    this.emit('parsed', data);
+};
+
+
+
+
 Parser.prototype._parseChunk = function(data, idx) {
@@ -162,2 +215,4 @@
         throw new Error('Unsupported critical chunk type ' + name);
+    // else
+    //     console.log('Ignoring chunk', name, type.toString(16));
 
@@ -198,8 +253,8 @@ return idx;
     if (depth != 8)
-        throw new Error('Unsupported bit depth');
-    if (colorType != 6)
-        throw new Error('Unsupported color type');
+        throw new Error('Unsupported bit depth ' + depth);
     if (interlace != 0)
         throw new Error('Unsupported interlace method');
 
+    this._colorType = colorType;
+
     this._compress.prepareInflate(compr);
@@ -228,3 +283,44 @@ this._filter.prepare(width, height, filter);
 
+Parser.prototype._parsePLTE = function(data) {
+
+    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
+        ]);
+    }
+};
+
+Parser.prototype._parseTRNS = function(data) {
+
+    // palette
+    if (this._colorType == 3) {
+        if (this._palette.length == 0)
+            throw new Error('Transparency chunk must be after palette');
+
+        if (data.length > this._palette.length)
+            throw new Error('More transparent colors than palette size');
+
+        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
+};
+
+Parser.prototype._parseGAMA = function(data) {
+    this.emit('gamma', data.readUInt32BE(0) / 100000);
+};
+
 Parser.prototype._parseIDAT = function(data) {
+
+    if (this._colorType == 3 && this._palette.length == 0)
+        throw new Error('Expected palette not found');
+
     this._compress.writeInflate(data);
@@ -231,0 +327,0 @@ };

lib/png.js

@@ -29,3 +29,3 @@ // Copyright (c) 2012 Kuba Niegowski
 var PNG = exports.PNG = function(options) {
-    Parser.call(this, options);
+    Parser.call(this, options = options || {});
 
@@ -38,3 +38,3 @@ this.width = options.width || 0;
 
-    this.on('metadata', this._metadata.bind(this));
+    this.gamma = 0;
 
@@ -45,2 +45,5 @@ this.readable = this.writable = true;
 
+    this.on('metadata', this._metadata.bind(this));
+    this.on('gamma', this._gamma.bind(this));
+
     this.on('parsed', function(data) {
@@ -55,2 +58,3 @@ this.data = data;
     this._pack(this.width, this.height, this.data);
+    return this;
 };
@@ -80,2 +84,3 @@
     this._parse(data);
+    return this;
 };
@@ -86,2 +91,3 @@
     this._buffLen += data.length;
+    return true;
 };
@@ -101,1 +107,27 @@
 };
+
+PNG.prototype._gamma = function(gamma) {
+    this.gamma = gamma;
+};
+
+PNG.prototype.bitblt = function(dst, sx, sy, w, h, dx, dy) {
+
+    var src = this;
+
+    if (sx > src.width || sy > 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)
+        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
+        );
+    }
+
+    return this;
+};

package.json

 {
     "name": "pngjs",
-    "version": "0.1.0-alpha",
+    "version": "0.2.0-alpha",
     "description": "Simple PNG encoder/decoder",
@@ -5,0 +5,0 @@ "author": "Kuba Niegowski",

README.md

@@ -18,6 +18,4 @@ About
 var png = new PNG({
-        filterType: 4
-    }),
-    src = fs.createReadStream(process.argv[2]),
-    dst = fs.createWriteStream(process.argv[3]);
+    filterType: 4
+});
 
@@ -40,6 +38,8 @@ png.on('parsed', function() {
 
+    png.pipe(fs.createWriteStream('out.png'));
+
     png.pack();
 });
 
-src.pipe(png).pipe(dst);
+fs.createReadStream('in.png').pipe(png);
 ```
@@ -51,7 +51,10 @@ For more examples see `examples` folder.
 
-Currently only true color mode with 8-bit color depth (per color) with alpha
-is supported. PNG cannot parse and create images with palette of colors.
-Interlaced mode is not supported either.
+As input any color type is accepted (grayscale, rgb, palette, grayscale with alpha, rgb with alpha) but 8 bit per sample (channel) is the only supported bit depth. Interlaced mode is not supported.
 
-## PNG
+### Supported ancillary chunks
+- `gAMA` - gamma,
+- `tRNS` - transparency (but only for paletted image)
+
+
+## Class: PNG
 `PNG` is readable and writeable `Stream`.
@@ -86,5 +89,11 @@
 
+### Property: gamma
+
 Changelog
 ============
 
+### 0.2.0-alpha - 21 Aug 2012
+  - Input added palette, grayscale, no alpha support
+  - Better scanline filter selection
+
 ### 0.1.0-alpha - 19 Aug 2012
@@ -91,0 +100,0 @@ - First version

New alerts

License Policy Violation

License

This package is not allowed per your license policy. Review the package's license to ensure compliance.

Found 1 instance in 1 package

Mixed license

License

(Experimental) Package contains multiple licenses.

Found 1 instance in 1 package

Non-permissive License

License

(Experimental) A license not known to be considered permissive was found.

Found 1 instance in 1 package

Unidentified License

License

(Experimental) Something that seems like a license was found, but its contents could not be matched with a known license.

Found 1 instance in 1 package

Fixed alerts

License Policy Violation

License

This package is not allowed per your license policy. Review the package's license to ensure compliance.

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

54301

increased by108.36%

Number of package files

37

increased by270%

Lines of code

746

increased by31.34%

Number of lines in readme file

122

increased by7.96%

Worsened metrics

Number of low license alerts

3

increased byInfinity%

License quality

80

decreased by-20%

Number of low supply chain risk alerts

5

increased by66.67%

No dependency changes