Convert YCCK to CMYK (JPEG)
SSE2
| FwStatus | fwiYCCKToCMYK_JPEG_8u_P4R | ( | const Fw8u * const pSrcYCCK[4], int srcStep, Fw8u * pDstCMYK[4], int dstStep, FwiSize roiSize ); | |
| FwStatus | fwiYCCKToCMYK_JPEG_8u_P4C4R | ( | const Fw8u * const pSrcYCCK[4], int srcStep, Fw8u * pDstCMYK, int dstStep, FwiSize roiSize ); |
| dstStep | Destination buffer step size (width of the buffer in bytes). | |
| pDstCMYK | Pointer to destination image ROI for CMYK image format. | |
| pDstCMYK[4] | Pointer to destination image ROI for CMYK image format (four-channel planar). | |
| pSrcYCCK[4] | Pointer to source image ROI for YCCK image format (four-channel planar). | |
| roiSize | Specifies the height and width of an ROI. | |
| srcStep | Source buffer step size (width of the buffer in bytes). |
These function step through an ROI in a source buffer, convert source data from the YCCK color space to the CMYK color model, and write the converted data to a destination buffer.
The following formulas are used to convert luminance and chrominance values to red, green, and blue values.
R = Y + 1.402*Cr - 179.456 G = Y - 0.34414*Cb - 0.71414*Cr + 135.45984 B = Y + 1.772*Cb - 226.816
The following formulas are used to convert red, green, and blue values to cyan, magenta, and yellow values.
C = 255 -R M = 255 -G Y = 255 -B
The black (K) channel value remains the same during conversion.