question on ippiRGBToYCbCr411LS_MCU_8u16s_C3P3R function?

[nyryder]

The function ippiRGBToYCbCr411LS_MCU_8u16s_C3P3R creates 4:1:1 MCUs, my question is how it is creating 4:1:1 MCUS?. Is it done by 4:1 horinzontal downsampling(taking 4 samples horizontally and average it to one value)or by 2:1 horizontal downsampling and 2:1 vertical downsampling (taking a 2x2 matrix on cb and cr and average it to one value)

[Chao_Y_Intel]

Quoting - nyryder

The function ippiRGBToYCbCr411LS_MCU_8u16s_C3P3R creates 4:1:1 MCUs, my question is how it is creating 4:1:1 MCUS?. Is it done by 4:1 horinzontal downsampling(taking 4 samples horizontally and average it to one value)or by 2:1 horizontal downsampling and 2:1 vertical downsampling (taking a 2x2 matrix on cb and cr and average it to one value)

Hi

The Cb and Cr are reduced 2:1 horizontally and 2:1 vertically. The Figure 6-13 'MCU Structure for Different JPEG Sampling Formats' in the ippi manual (ippiman.pdf) can provide more information.

Thanks,
Chao