A Hybrid JPEG & JPEG 2000 Image Compression Scheme for Gray Images

Image compression method is trying to reduce number of bits per pixel for sufficient representation of image, so memory needed for storing necessary information is reduced and communication efficiency is upgraded. The goal of compression algorithms is to gain best compression ratio with acceptable visual quality, the proposed compression satisfy this goal. Transform with DCT (Discrete Cosine Transform) and DWT (Discrete Wavelet Transform) is most commonly used. DCT has high energy compaction property and requires less computational resources. On other hand, DWT multiresolution Transformation. In this paper, we propose a Hybrid DWT-DCT algorithm for image compression and reconstruction taking benefit from the advantages of both algorithms. The simulation results show that the proposed Hybrid DWT-DCT algorithm performs much better than standalone JPEG based DCT, and JPEG 2000 based DWT in terms of BPP (bits per pixel) and CR (compression ratio).