چكيده فارسي :
Nowadays, the development and progress of multimedia product grows increasingly fast, and it is needed to adapt with insufficient bandwidth of network and storage of memory device. Therefore, the theory of data compression becomes more and more important for reducing the data redundancy to use less hardware space and transmission bandwidth. So many image compression methods is proposed to decrease image size with minimum information loosing. This paper describes a color image compression technique based on Discrete Wavelet Transform (DWT) and Cat Swarm Optimization (CSO). High degree of correlation between the RGB planes of a color image is reduced by transforming them to more suitable space by using the CSO. This optimization method would enable us to find a transform that maximize the energy of one dimension in comparison with other dimensions. After RGB transformation, wavelet transform is applied to each components 3 times. Then thresholding, quantization, two rule and arithmetic encoding are applied to resulted image and compressed image is resulted. The result of the proposed method is compared with previous similar published methods and the former is found superior in terms of quality of the reconstructed image. Further, proposed method is efficient in compression ability.
