make sure all raw pixel buffers are converted to 4 channels...

because encoders expect images to have 4 channels.
EyalAr · Oct 2, 2015 · 1138482 · 1138482
1 parent 2a60f34
commit 1138482
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Showing 2 changed files with 33 additions and 4 deletions.
diff --git a/lib/obtain.js b/lib/obtain.js
@@ -33,13 +33,13 @@
                     });
                 });
             } else if (source instanceof Buffer) {
-                if(typeof type === 'object') {
+                if (typeof type === 'object') {
                     // it's a raw pixels buffer
                     var channelSize = type.width * type.height;
                     var numChannels = source.length / channelSize;
-                    if (numChannels !== parseInt(numChannels) || numChannels < 1 || numChannels > 4) {
+                    if (numChannels !== parseInt(numChannels) || numChannels < 1 || numChannels > 4)
                         throw Error("Buffer size does not match width and height");
-                    }
+                    if (numChannels !== 4) source = util.makeRgbaBuffer(source, numChannels);
                     callback(null, new Image(source, type.width, type.height, (numChannels % 2 === 0)));
                 } else if (typeof type === 'string') {
                     // it's an encoded image

diff --git a/lib/util.js b/lib/util.js
@@ -134,13 +134,42 @@
         return 256;
     }
 
+    function makeRgbaBuffer(orig, channels){
+        var chanLen = orig.length / channels;
+        if (chanLen !== parseInt(chanLen) || channels < 1 || channels > 3)
+            throw Error("Incorrect number of channels in original buffer");
+        var rgba = new Buffer(chanLen * 4);
+        switch (channels){
+            case 1:
+                orig.copy(rgba, 0, 0, chanLen);
+                orig.copy(rgba, chanLen, 0, chanLen);
+                orig.copy(rgba, 2 * chanLen, 0, chanLen);
+                rgba.fill(100, 3 * chanLen);
+                break;
+            case 2:
+                orig.copy(rgba, 0, 0, chanLen);
+                orig.copy(rgba, chanLen, 0, chanLen);
+                orig.copy(rgba, 2 * chanLen, 0, chanLen);
+                orig.copy(rgba, 3 * chanLen, chanLen);
+                break;
+            case 3:
+                orig.copy(rgba, 0, 0, chanLen);
+                orig.copy(rgba, chanLen, chanLen, 2 * chanLen);
+                orig.copy(rgba, 2 * chanLen, 2 * chanLen);
+                rgba.fill(100, 3 * chanLen);
+                break;
+        }
+        return rgba;
+    }
+
     module.exports = {
         undefinedFilter: undefinedFilter,
         normalizeColor: normalizeColor,
         normalizePngParams: normalizePngParams,
         normalizeGifParams: normalizeGifParams,
         normalizeJpegParams: normalizeJpegParams,
-        getClosest2Exp: getClosest2Exp
+        getClosest2Exp: getClosest2Exp,
+        makeRgbaBuffer: makeRgbaBuffer
     };
 
 })(void 0);