Chroma Subsampling

• How to decimate for chrominance (Fig. 6.30)?

Chroma Subsampling

• 4:2:2 -> Horizontally subsampled colour signals by a factor of 2. Each pixel is two bytes, e.g., (Cb0, Y0)(Cr0, Y1)(Cb2, Y2)(Cr2, Y3)(Cb4, Y4) ...

• 4:1:1 -> Horizontally subsampled by a factor of 4

• 4:2:0 -> Subsampled in both the horizontal and vertical axes by a factor of 2 between pixels as shown in the Fig. 6.30.

• 4:1:1 and 4:2:0 are mostly used in JPEG and MPEG (see Chapter 4).