COLOR SPACE SELECTION FOR JPEG IMAGE COMPRESSION

The Joint Photographic Experts Group's image compression algorithm has been shown to provide a very efficient and powerful method of compres sing images. However, there is little substantive information about wh ich color space should be utilized when implementing the JPEG algorith m. Currently, the JPEG algorithm is set up for use with any three-comp onent color space. The objective of this research is to determine whet her pr not the color space selected will significantly improve the ima ge compression. The RGB, XYZ, YIQ, CIELAB, CIELUV, and CIELAB LCh, col or spaces were examined and compared. Both numerical measures and psyc ho-physical techniques were used to assess the results. The final resu lts indicate that the device space, RGB, is the worst color space to c ompress images. In comparison, the nonlinear transforms of the device space, CIELAB and CIELUV, are the best color spaces to compress images . The XYZ, YIQ, and CIELAB LCh color spaces resulted in intermediate l evels of compression.