diff options
Diffstat (limited to 'base')
| -rw-r--r-- | base/gfx/png_encoder.cc | 39 |
1 files changed, 34 insertions, 5 deletions
diff --git a/base/gfx/png_encoder.cc b/base/gfx/png_encoder.cc index 5021721..f8b4bf0 100644 --- a/base/gfx/png_encoder.cc +++ b/base/gfx/png_encoder.cc @@ -5,6 +5,7 @@ #include "base/basictypes.h" #include "base/gfx/png_encoder.h" #include "base/logging.h" +#include "base/scoped_ptr.h" #include "third_party/skia/include/core/SkBitmap.h" extern "C" { @@ -197,9 +198,37 @@ bool PNGEncoder::Encode(const unsigned char* input, ColorFormat format, bool PNGEncoder::EncodeBGRASkBitmap(const SkBitmap& input, bool discard_transparency, std::vector<unsigned char>* output) { - SkAutoLockPixels input_lock(input); - DCHECK(input.empty() || input.bytesPerPixel() == 4); - return Encode(static_cast<unsigned char*>(input.getPixels()), - PNGEncoder::FORMAT_BGRA, input.width(), input.height(), - input.rowBytes(), discard_transparency, output); + static const int bbp = 4; + + SkAutoLockPixels lock_input(input); + DCHECK(input.empty() || input.bytesPerPixel() == bbp); + + // SkBitmaps are premultiplied, we need to unpremultiply them. + scoped_array<unsigned char> divided( + new unsigned char[input.width() * input.height() * bbp]); + + int i = 0; + for (int y = 0; y < input.height(); y++) { + for (int x = 0; x < input.width(); x++) { + uint32 pixel = input.getAddr32(0, y)[x]; + + int alpha = SkColorGetA(pixel); + if (alpha != 0 && alpha != 255) { + divided[i + 0] = (SkColorGetR(pixel) << 8) / alpha; + divided[i + 1] = (SkColorGetG(pixel) << 8) / alpha; + divided[i + 2] = (SkColorGetB(pixel) << 8) / alpha; + divided[i + 3] = alpha; + } else { + divided[i + 0] = SkColorGetR(pixel); + divided[i + 1] = SkColorGetG(pixel); + divided[i + 2] = SkColorGetB(pixel); + divided[i + 3] = alpha; + } + i += bbp; + } + } + + return Encode(divided.get(), + PNGEncoder::FORMAT_RGBA, input.width(), input.height(), + input.width() * bbp, discard_transparency, output); } |