JPEGImageDecoder RGB565 and downsample support and related Skia imagegenerator changes

third_party/WebKit/Source/platform/image-decoders/jpeg/JPEGImageDecoderTest.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 84 matching lines @@
     ASSERT_TRUE(size.height() == ySize.height());
     ASSERT_TRUE(uSize.width() == vSize.width());
     ASSERT_TRUE(uSize.height() == vSize.height());
 
     *outputYWidth = ySize.width();
     *outputYHeight = ySize.height();
     *outputUVWidth = uSize.width();
     *outputUVHeight = uSize.height();
 }
 
+static inline void compareDiffHelper(int c, int treshold, int &counter)
+{
+    if (c > treshold) {
+        ++counter;
+    }
+}
+
+static inline int max(int x, int y)
+{
+    return x > y ? x : y;
+}
+
+static void comparePixels(const SkBitmap &b1, const SkBitmap &b2, int treshold, int &countAboveTreshold, int componentTreshold, int &countComponentAboveTreshold)
+{
+    countAboveTreshold = 0;
+    countComponentAboveTreshold = 0;
+    for (int i = 0; i < b1.height(); ++i) {
+        for (int j = 0; j < b1.width(); ++j) {
+            SkColor c1 = b1.getColor(i, j);
+            SkColor c2 = b2.getColor(i, j);
+            unsigned a = abs((int)((c1 >> 24) & 0xFF) - (int)((c2 >> 24) & 0xFF));
+            unsigned r = abs((int)((c1 >> 16) & 0xFF) - (int)((c2 >> 16) & 0xFF));
+            unsigned g = abs((int)((c1 >> 8) & 0xFF) - (int)((c2 >> 8) & 0xFF));
+            unsigned b = abs((int)(c1 & 0xFF) - (int)(c2 & 0xFF));
+
+            int diff = a + r + g + b;
+            int c = max(max(a, r), max(g, b));
+            compareDiffHelper(c, componentTreshold, countComponentAboveTreshold);
+            compareDiffHelper(diff, treshold, countAboveTreshold);
+        }
+    }
+}
+
+static void testRGB565Quality(const char* imageFilePath)
+{
+    RefPtr<SharedBuffer> data = readFile(imageFilePath);
+    ASSERT_TRUE(data);
+
+    OwnPtr<ImageDecoder> decoder = createDecoder();
+    decoder->setData(data.get(), true);
+
+    ImageFrame* frame = decoder->frameBufferAtIndex(0);
+    ASSERT_TRUE(frame);
+
+    OwnPtr<ImageDecoder> decoder565 = createDecoder();
+    decoder565->setData(data.get(), true);
+    ASSERT_TRUE(decoder565->setDecodeRGB565Enabled(true));
+    ImageFrame* frame565 = decoder565->frameBufferAtIndex(0);
+    ASSERT_TRUE(frame565);
+
+    EXPECT_EQ(frame->getSkBitmap().width(), frame565->getSkBitmap().width());
+    EXPECT_EQ(frame->getSkBitmap().height(), frame565->getSkBitmap().height());
+    EXPECT_EQ(frame565->getSkBitmap().colorType(), kRGB_565_SkColorType);
+    frame->getSkBitmap().lockPixels();
+    frame565->getSkBitmap().lockPixels();
+#if USE(QCMSLIB)
+    int diffTreshold = 15;
+    int componentDiffTreshold = 7;
+    float allowedDiff = 0.003f;
+    float allowedComponentsDiff = 0.005f;
+#else
+    int diffTreshold = 30;
+    int componentDiffTreshold = 15;
+    float allowedDiff = 0.027f;
+    float allowedComponentsDiff = 0.022f;
+#endif
+    int countAboveTreshold, countComponentAboveTreshold;
+    comparePixels(frame->getSkBitmap(), frame565->getSkBitmap(), diffTreshold, countAboveTreshold, componentDiffTreshold, countComponentAboveTreshold);
+    frame->getSkBitmap().unlockPixels();
+    frame565->getSkBitmap().unlockPixels();
+    // not real quality marker here, just a number to track regression
+    EXPECT_GE(allowedDiff, (float) countAboveTreshold / (float) (frame->getSkBitmap().width() * frame->getSkBitmap().height()))
+        << "Value measured and added when implementing this - once you hit this regressing, just check if all OK and update the value.";
+    EXPECT_GE(allowedComponentsDiff, (float) countComponentAboveTreshold / (float) (frame->getSkBitmap().width() * frame->getSkBitmap().height()))
+        << "Value measured and added when implementing this - once you hit this regressing, just check if all OK and update the value.";
+}
+
 // Tests failure on a too big image.
 TEST(JPEGImageDecoderTest, tooBig)
 {
     OwnPtr<ImageDecoder> decoder = createDecoder(100);
     EXPECT_FALSE(decoder->setSize(10000, 10000));
     EXPECT_TRUE(decoder->failed());
 }
 
 // Tests that JPEG decoder can downsample image whose width and height are multiple of 8,
 // to ensure we compute the correct decodedSize and pass correct parameters to libjpeg to
@@ skipping 162 matching lines @@
     // segments into the contiguous buffer. If JPEGImageDecoder was pointing to
     // data in a segment, its pointer would no longer be valid.
     segmentedData->data();
 
     ImageFrame* frame = decoder->frameBufferAtIndex(0);
     ASSERT_FALSE(decoder->failed());
     EXPECT_EQ(frame->status(), ImageFrame::FrameComplete);
     EXPECT_EQ(hashBitmap(frame->bitmap()), hash);
 }
 
+TEST(JPEGImageDecoderTest, rgb565AndQuality)
+{
+    testRGB565Quality("/LayoutTests/fast/images/resources/cmyk-jpeg.jpg");
+    testRGB565Quality("/LayoutTests/fast/images/resources/ycbcr-with-no-color-profile.jpg");
+    testRGB565Quality("/LayoutTests/fast/images/resources/red-at-12-oclock-with-color-profile.jpg");
+}
+
 } // namespace blink