3D balance quantization encoding based on variable size matrix segmentation

Variable size matrix segmentation and variable size transform are used in the colour image compression methods based on three dimensional matrix widely discrete cosine transform (3DMWDCT). However the coefficients have different statistical properties since different areas of an image and difference size blocks have difference energy centralization. 3D balance quantization based human visual system was proposed in this paper. After dividing the original colour image into variable sized sub-three dimensional matrices according to the activity characteristics of the image, the variable sized 3DMWDCT is applied to the corresponding sized sub three dimensional matrices. DCT coefficients were 3D balance quantized through non-linear scalar quantization and entropy coding. Experimental results show that the compression efficiency of the proposed algorithm is better than that of JPEG. Compared with JPEG, the proposed algorithm improves PSNR at most 2dB, and the quality of the reconstructed image is improved in subject evaluation too.