template <J_COLOR_SPACE colorSpace> void setPixel(ImageFrame& buffer, ImageFrame::PixelData* pixel, JSAMPARRAY samples, int column)
{
JSAMPLE* jsample = *samples + column * (colorSpace == JCS_RGB ? 3 : 4);
switch (colorSpace) {
case JCS_RGB:
buffer.setRGBARaw(pixel, jsample[0], jsample[1], jsample[2], 255);
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.setRGBARaw(pixel, jsample[0] * k / 255, jsample[1] * k / 255, jsample[2] * k / 255, 255);
break;
}
}
