Abstract:

JPEG2000 based on wavelet transform is the next generation still image coding standard. It has many advantages. But the two-dimensional wavelet is just the tensor product of one-dimensional wavelet. It can not capture the image direction information well because of its lack of directions. Waveletbased contourlet transform (WBCT) based on directional filter can make up this deficiency. Compared with the wavelet transform, WBCT can more sparsely express image information and is embedded in the JPEG2000 framework. And a new still image compression algorithm, based on optimal decomposition and directional weighting is proposed. The experimental results show that the algorithm has better effect on contours and strong texture information of images in low bit-rate and weak texture information in high bit-rate, and it has better compression performance than JPEG2000 whether on objective evaluation methods or subjective visual feeling.