Using Different Color Models to Test JPEG and Modified JPEG

Abstract

In this paper, issues of storage and transmission of high quality color images were discussed. JPEG is the most robust algorithm being used for image compression. The cubic spline interpolation (CSI) has previously been used in JPEG1992 to improve its performance for medical images. In current work, CSI was amalgamated with JPEG 1992 standard for color image compression. In addition, different color models were also incorporated into JPEG to compare the performance of JPEG and modified JPEG named as CSI-JPEG. The JPEG was modified at two stages called color space conversion and down sampling stage and was tested by incorporating different color models. The results showed that CSI-JPEG algorithm provided about 30% more compression rate on average for same visual quality as compared to traditional JPEG algorithm. Moreover, CAM02-UCS was found to perform best in terms of compression rate and image quality for both of the algorithms. By statistical significance test, the performance of CAM02-UCS was proved significantly better comparing with non-uniform color spaces and the performance difference of CSI-JPEG and JPEG was also significant. This also implies that CAM02-UCS is a more visually uniform color space than CIELAB and CIELUV. Psychophysical experiments were also conducted that validated the test results.