A New Preprocessing Algorithm Used in Color Image Compression

Still image compression algorithms have been long aiming at gray-scale image compression, in this paper we exploit a new method to improve coding efficiency of color image compression. Firstly, the combination of color space transform and wavelet transform is examined and found out the best one. Then a weighting scheme is proposed to improve objective quality of reconstruction image further. Experimental results show that the proposed scheme not only outperforms JPEG2000 lossy transform scheme and JPEG2000 lossless transform scheme in objective quality by 1–2 db. By conservative estimation, the proposed algorithm outperforms JPEG2000 lossy algorithm from 0.2BPP to 6 BPP and can be used in most practical compression situations.