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