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authorglen@chromium.org <glen@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98>2009-06-24 16:40:08 +0000
committerglen@chromium.org <glen@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98>2009-06-24 16:40:08 +0000
commit9f9c5296b022dc280cd38ff418f5177cf71856d6 (patch)
treeed04612bdbcdb6730598b6628e2755aba7275525 /base/gfx/png_codec_unittest.cc
parent52856c37b4d928a593a7fbdbb8171c5197795488 (diff)
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PNGDecoder wasn't multiplying the alpha like PNGEncoder was. This lead to color
overflow. This intermediate fix makes everything correct, but will make alphaed pixels slightly darker until the user's cache is flushed (I have screenshots of the effect). BUG=13360 TEST=none Review URL: http://codereview.chromium.org/147049 git-svn-id: svn://svn.chromium.org/chrome/trunk/src@19131 0039d316-1c4b-4281-b951-d872f2087c98
Diffstat (limited to 'base/gfx/png_codec_unittest.cc')
-rw-r--r--base/gfx/png_codec_unittest.cc47
1 files changed, 47 insertions, 0 deletions
diff --git a/base/gfx/png_codec_unittest.cc b/base/gfx/png_codec_unittest.cc
index 9184abe..c9734a7 100644
--- a/base/gfx/png_codec_unittest.cc
+++ b/base/gfx/png_codec_unittest.cc
@@ -7,6 +7,7 @@
#include "base/gfx/png_encoder.h"
#include "base/gfx/png_decoder.h"
#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/skia/include/core/SkBitmap.h"
static void MakeRGBImage(int w, int h, std::vector<unsigned char>* dat) {
dat->resize(w * h * 3);
@@ -41,6 +42,25 @@ static void MakeRGBAImage(int w, int h, bool use_transparency,
}
}
+// Returns true if each channel of the given two colors are "close." This is
+// used for comparing colors where rounding errors may cause off-by-one.
+bool ColorsClose(uint32_t a, uint32_t b) {
+ return abs(static_cast<int>(SkColorGetB(a) - SkColorGetB(b))) < 2 &&
+ abs(static_cast<int>(SkColorGetG(a) - SkColorGetG(b))) < 2 &&
+ abs(static_cast<int>(SkColorGetR(a) - SkColorGetR(b))) < 2 &&
+ abs(static_cast<int>(SkColorGetA(a) - SkColorGetA(b))) < 2;
+}
+
+void MakeTestSkBitmap(int w, int h, SkBitmap* bmp) {
+ bmp->setConfig(SkBitmap::kARGB_8888_Config, w, h);
+ bmp->allocPixels();
+
+ uint32_t* src_data = bmp->getAddr32(0, 0);
+ for (int i = 0; i < w * h; i++) {
+ src_data[i] = SkPreMultiplyARGB(i % 255, i % 250, i % 245, i % 240);
+ }
+}
+
TEST(PNGCodec, EncodeDecodeRGB) {
const int w = 20, h = 20;
@@ -200,3 +220,30 @@ TEST(PNGCodec, StripAddAlpha) {
ASSERT_EQ(original_rgb.size(), decoded.size());
ASSERT_TRUE(original_rgb == decoded);
}
+
+TEST(PNGCodec, EncodeBGRASkBitmap) {
+ const int w = 20, h = 20;
+
+ SkBitmap original_bitmap;
+ MakeTestSkBitmap(w, h, &original_bitmap);
+
+ // Encode the bitmap.
+ std::vector<unsigned char> encoded;
+ PNGEncoder::EncodeBGRASkBitmap(original_bitmap, false, &encoded);
+
+ // Decode the encoded string.
+ SkBitmap decoded_bitmap;
+ EXPECT_TRUE(PNGDecoder::Decode(&encoded, &decoded_bitmap));
+
+ // Compare the original bitmap and the output bitmap. We use ColorsClose
+ // as SkBitmaps are considered to be pre-multiplied, the unpremultiplication
+ // (in Encode) and repremultiplication (in Decode) can be lossy.
+ for (int x = 0; x < w; x++) {
+ for (int y = 0; y < h; y++) {
+ uint32_t original_pixel = original_bitmap.getAddr32(0, y)[x];
+ uint32_t decoded_pixel = decoded_bitmap.getAddr32(0, y)[x];
+ EXPECT_TRUE(ColorsClose(original_pixel, decoded_pixel));
+ }
+ }
+}
+