The intensity distribution of most original remote sensing images concentrated in a narrow range

resulting in unclear image details and low contrast of the image. Histogram equalization is commonly used to distribute the gray levels of an image uniformg which can increase the contrast of images and enhanced the details. Through the elaboration of the definition of comentropy

we draw forth the image enhancement algorithm of histogram equalization. Then

we put forward an improved algorithm of ideal histogram equalization

which is based on piecewise mapping thoughts through the analysis of the defects existing in the traditional histogram equalization. In addition

we relate and analyze the implementation of the improved algorithm in this paper. Meanwhile

in order to do the quantitative analysis and comparison between the traditional algorithm and the modified algorithm

we use synthetic average contrast

and details evaluation parameters

which are based on simultaneous contrast

the contrast resolution limit

and fuzzy mathematics.Finally

we use simultaneous contrast

synthetic average contrast

and details evaluation parameters as the indexes of quantitative evaluation and quantitative evaluation of the improved algorithm. The results of quantitative evaluation show that the image enhancement effect of the improved algorithm proposed in this paper is better than the algorithm of traditional histogram equalization.