Chroma Subsampling is reduced color resolution in digital component video signals. To accommodate storage and bandwidth restrictions, the two color components (Cb, Cr) in digital video signals are compressed by sampling them at a lower rate than the brightness (Y). Some color information is discarded. Cb = luminance blue, Cr = luminance red, green is calculated. YCbCr is the YUV color space recorded digitally. Y is brightness (luma), and Cb and Cr are the U and V color difference signals. In chroma subsampling, the colors are compressed, the luma is not compressed because the eye is sensitive to brightness more than it is to color components.