Compression-related properties of color spaces

In modem color imaging a variety of color spaces are used to represent an image. It has been well established in literature that the choice of color space has an impact on the achievable compression. The purpose of this research is to investigate compression related properties of various color spaces. We investigated what we considered to be the most popular color spaces used today, namely, RGB, YIQ, YUV, YCbCr, HSI, CMYK, XYZ and CIELab. The following properties of color spaces that influence compressibility have been studied: energy distribution among color planes, plane bandwidth, DCT energy compaction, and impact of gamma correction. We also compared the compressibility of low resolution images (512x512), which have been used for most of the compression results reported in literature, with high resolution images (2048x2560), which are becoming increasingly important for modern imaging applications. The findings of this research have been illustrated by comparing the actual JPEG compression results for YCbCr and CIELab spaces.