关键词: 双直方图均衡, 亮度均值, 熵, 均匀化

Abstract: Based on Brightness preserving Bi-Histogram Equalization (BBHE), an improved algorithm of gray image enhancement was proposed. An appropriate threshold, which was selected based on the entropy of the output image and the difference between the mean brightness of input and output images, was selected to cut the image, then BBHE and gray lever homogenization were performed respectively. This method makes the brightness mean error as small as possible and the entropy of output image as large as possible. Meanwhile, it can prevent over-enhancement. The experimental results prove that the new method has better performance on image enhancement.

Key words: histogram equalization, mean brightness, entropy, homogenization