Analysis of Application of Arithmetic coding on DCT and DCT-DWT Hybrid Transforms of Images for Compression

摘要

The main aim of image compression is to represent the image at minimum amount of bytes. This paper presents a new algorithm that reduces number of bytes required to represent images. The proposed system divides the color image into RGB components, CMY components, YCbCr components separately and DCT and DWT are applied to each component and arithmetic coding is applied to the resultant and then their compression ratios are calculated. The results of DCT based arithmetic encoder and DCT-DWT hybrid arithmetic encoder is compared. It is observed that DCT-DWT hybrid arithmetic encoder approach outperforms DCT-based arithmetic encoder approach. It is also observed that the performance of the DCT-DWT hybrid arithmetic encoder based image compression system is best when the YCbCr components are evaluated. RGB and CMY component based compression provides similar results. This approach is also compared with Colour image compression algorithm based on the DCT transform using difference lookup table.