void WEBPImageDecoder::applyColorProfile(const uint8_t* data, size_t size, ImageFrame& buffer)
{
int width;
int decodedHeight;
if (!WebPIDecGetRGB(m_decoder, &decodedHeight, &width, 0, 0))
return; // See also https://bugs.webkit.org/show_bug.cgi?id=74062
if (decodedHeight <= 0)
return;
if (!m_haveReadProfile) {
readColorProfile(data, size);
m_haveReadProfile = true;
}
ASSERT(width == scaledSize().width());
ASSERT(decodedHeight <= scaledSize().height());
for (int y = m_decodedHeight; y < decodedHeight; ++y) {
uint8_t* row = reinterpret_cast<uint8_t*>(buffer.getAddr(0, y));
if (qcms_transform* transform = colorTransform())
qcms_transform_data_type(transform, row, row, width, QCMS_OUTPUT_RGBX);
uint8_t* pixel = row;
for (int x = 0; x < width; ++x, pixel += 4)
buffer.setRGBA(x, y, pixel[0], pixel[1], pixel[2], pixel[3]);
}
m_decodedHeight = decodedHeight;
}
void setPixel(ImageFrame& buffer, ImageFrame::PixelData* currentAddress, JSAMPARRAY samples, int column)
{
JSAMPLE* jsample = *samples + column * (colorSpace == JCS_RGB ? 3 : 4);
switch (colorSpace) {
case JCS_RGB:
buffer.setRGBA(currentAddress, jsample[0], jsample[1], jsample[2], 0xFF);
break;
case JCS_CMYK:
// Source is 'Inverted CMYK', output is RGB.
// See: http://www.easyrgb.com/math.php?MATH=M12#text12
// Or: http://www.ilkeratalay.com/colorspacesfaq.php#rgb
// From CMYK to CMY:
// X = X * (1 - K ) + K [for X = C, M, or Y]
// Thus, from Inverted CMYK to CMY is:
// X = (1-iX) * (1 - (1-iK)) + (1-iK) => 1 - iX*iK
// From CMY (0..1) to RGB (0..1):
// R = 1 - C => 1 - (1 - iC*iK) => iC*iK [G and B similar]
unsigned k = jsample[3];
buffer.setRGBA(currentAddress, jsample[0] * k / 255, jsample[1] * k / 255, jsample[2] * k / 255, 0xFF);
break;
}
}