One of the most important reasons of the existence of different types of\nfiles with media (audio or video) content, is achieving compression and less\nsize, while preserving quality. In terms of fast transportation of files\nbetween equipment and networks and decrease of the required storage space,\ncompression have always been under attention and action. Considering what was\nmentioned, in general, the concept of compression can be divided into two\nclasses of lossy and lossless. In the lossy method, a part of data is omitted,\nbut in the lossless methods, no data is omitted for compression. At the end of\nthis article, a lossless compression method is presented using Imperialist\ncompetitive algorithm for compression. The proposed algorithm tries to achieve\na more optimized color for the image color-map, so that it increases the\ncompression rate. The simulation results indicate that the proposed algorithm\ncan perform the compression by 43 percent and show its superiority compared to\nother similar methods.\n