Image Compression using Cosine – Slant Hybrid Wavelet Transform with Assorted Color Spaces

Gigantic size of multimedia data and images being generated stored and transmitted across the digital web today, which has raised new research concerns in computing field. One of such concerns is compression of such data with minimal quality distortion. In recent work, the hybrid wavelet transforms (HWT) are proven to be better in image compression as compared to the constituent transforms considered individually [1, 2]. Then further the proportion wise performance comparison of the constituent transforms considered for generation of HWT is also studied [3, 4]. Here the paper presents the performance appraise of various color spaces along with the conventional RGB color space in image compression using cosine-slant HWT with varying proportions of constituent cosine and slant transforms. The experimentation is done on a test-bed having 15 images of various sizes and varied compression ratios. The results show that LUV color space with 1:4 proportion of cosine-slant transform in HWT gives better quality of compression for higher compression ratios (90% and 95%). For 85% compression ratio, LUV color space with 1:1 proportion of cosine-slant transforms in HWT gives better compression quality. While in lower compression ratios (60% to 80%), the RGB color space gives better compression with 1:1 proportion of cosine-slant transforms in HWT. General Terms Image Compression.