In the process of image compression

the discrete cosine transform (DCT)makes the image blurry. With the frequency warping

the warped discrete cosine transform (WDCT)overcomes this shortcoming. However

it is difficult for traditional algorithms to select the frequency warping parameters. Therefore

in this paper

we present a new WDCT image compression algorithm based on an evolutionary algorithm (EAWDCT)to select the parameters with the global optimization of the evolutionary algorithm. To improve the convergence speed and to gain the best parameters quickly and accurately

a heuristic method is used to design the chromosome coding methods and evolutionary operators according to the parameters characteristics. The experiments show that the new algorithm (EAWDCT)improves the peak signal to noise ratio and signal to noise ratio while reducing the root-mean-square error effectively.