Special-case 24-bit RGB image-handling.

src/core/evaluator.js

@@ -166,7 +166,9 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
           (w + h) < SMALL_IMAGE_DIMENSIONS) {
         var imageObj = new PDFImage(this.xref, resources, image,
                                     inline, null, null);
-        var imgData = imageObj.createImageData();
+        // We force the use of 'rgba_32bpp' images here, because we can't
+        // handle any other kind.
+        var imgData = imageObj.createImageData(/* forceRGBA = */ true);
         operatorList.addOp(OPS.paintInlineImageXObject, [imgData]);
         return;
       }
@@ -189,7 +191,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
 
 
       PDFImage.buildImage(function(imageObj) {
-          var imgData = imageObj.createImageData();
+          var imgData = imageObj.createImageData(/* forceRGBA = */ false);
           self.handler.send('obj', [objId, self.pageIndex, 'Image', imgData],
                             null, [imgData.data.buffer]);
         }, self.handler, self.xref, resources, image, inline);

src/core/image.js

@@ -417,7 +417,7 @@ var PDFImage = (function PDFImageClosure() {
         buffer[i + 2] = clamp((buffer[i + 2] - matteRgb[2]) * k + matteRgb[2]);
       }
     },
-    createImageData: function PDFImage_createImageData() {
+    createImageData: function PDFImage_createImageData(forceRGBA) {
       var drawWidth = this.drawWidth;
       var drawHeight = this.drawHeight;
       var imgData = {       // other fields are filled in below
@@ -430,22 +430,27 @@ var PDFImage = (function PDFImageClosure() {
       var originalHeight = this.height;
       var bpc = this.bpc;
 
-      // rows start at byte boundary;
+      // Rows start at byte boundary.
       var rowBytes = (originalWidth * numComps * bpc + 7) >> 3;
       var imgArray = this.getImageBytes(originalHeight * rowBytes);
 
-      // imgArray can be incomplete (e.g. after CCITT fax encoding)
+      if (!forceRGBA) {
-      var actualHeight = 0 | (imgArray.length / rowBytes *
-                         drawHeight / originalHeight);
-
         // If it is a 1-bit-per-pixel grayscale (i.e. black-and-white) image
         // without any complications, we pass a same-sized copy to the main
-      // thread rather than expanding by 32x to RGBA form. This saves *lots* of
+        // thread rather than expanding by 32x to RGBA form. This saves *lots*
-      // memory for many scanned documents. It's also much faster.
+        // of memory for many scanned documents. It's also much faster.
-      if (this.colorSpace.name === 'DeviceGray' && bpc === 1 &&
+        //
-          !this.smask && !this.mask && !this.needsDecode &&
+        // Similarly, if it is a 24-bit-per pixel RGB image without any
+        // complications, we avoid expanding by 1.333x to RGBA form.
+        var kind;
+        if (this.colorSpace.name === 'DeviceGray' && bpc === 1) {
+          kind = 'grayscale_1bpp';
+        } else if (this.colorSpace.name === 'DeviceRGB' && bpc === 8) {
+          kind = 'rgb_24bpp';
+        }
+        if (kind && !this.smask && !this.mask && !this.needsDecode &&
             drawWidth === originalWidth && drawHeight === originalHeight) {
-        imgData.kind = 'grayscale_1bpp';
+          imgData.kind = kind;
 
           // We must make a copy of imgArray, otherwise it'll be neutered upon
           // transfer which will break any code that subsequently reuses it.
@@ -455,6 +460,11 @@ var PDFImage = (function PDFImageClosure() {
           imgData.origLength = imgArray.length;
           return imgData;
         }
+      }
+
+      // imgArray can be incomplete (e.g. after CCITT fax encoding).
+      var actualHeight = 0 | (imgArray.length / rowBytes *
+                         drawHeight / originalHeight);
 
       var comps = this.getComponents(imgArray);
 

src/display/canvas.js

@@ -526,6 +526,22 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
         ctx.putImageData(chunkImgData, 0, i * fullChunkHeight);
       }
 
+    } else if (imgData.kind === 'rgb_24bpp') {
+      // RGB, 24-bits per pixel.
+      for (var i = 0; i < totalChunks; i++) {
+        var thisChunkHeight =
+          (i < fullChunks) ? fullChunkHeight : partialChunkHeight;
+        var elemsInThisChunk = imgData.width * thisChunkHeight * 3;
+        var destPos = 0;
+        for (var j = 0; j < elemsInThisChunk; j += 3) {
+          chunkImgData.data[destPos++] = imgData.data[srcPos++];
+          chunkImgData.data[destPos++] = imgData.data[srcPos++];
+          chunkImgData.data[destPos++] = imgData.data[srcPos++];
+          chunkImgData.data[destPos++] = 255;
+        }
+        ctx.putImageData(chunkImgData, 0, i * fullChunkHeight);
+      }
+
     } else {
         error('bad image kind: ' + imgData.kind);
     }