The histogram equalization (HE) is one of the most popular methods for image contrast enhancement. However, HE algorithm has two main disadvantages. To solve these problems, this paper presents an improved image contrast enhancement based on histogram equalization, which is especially suitable for multiple-peak images. Firstly, the input image is convolved by a Gaussian filter with optimum parameters. Secondly, the original histogram can be divided into different areas by the valley values of the image histogram. Thirdly, using of our proposed method processes images. This method outperforms others on the aspects of simplicity and adaptability. We have applied the proposed algorithm on a database which includes 160 normal images and compared our proposed method with HE and BHE. The result demonstrates that the proposed algorithm has good performance in the field of image enhancement. This method can also be realized by simple hardware and consumer electronics, efficiently.