Image compression using wavelet transform and vector quantization with variable block size

Abstract

We introduced discrete wavelet transform (DWT) to vector quantization (VQ) for image compression. DWT is multi-resolution analysis, and a signal energy concentrates to specific DWT coefficients. This characteristics is useful for image compression. DWT coefficients are compressed using VQ with variable block size. To perform effective compression, blocks are merged by the algorithm proposed in this paper. Results of computational experiments show that our algorithm is effective compared with the performance of the previous proposed algorithm.