A novel image enhancement technique suitable for low light level image, dualistic sub image enhancement based on two dimensional histogram analysis and histogram equalization, is presented. Firstly, the low light level image is segmented to two sub images according to the correlation between the neighboring pixels, which is based on the two dimensional histogram analysis. Then each sub image is enhanced based on histogram equalization. Finally, the processed sub images are composed into one image. The result indicates that the algorithm can not only enhance image information effectively but also keep the fine part of original low light level image well. And this algorithm eliminates the drawback of traditional histogram that the fine part is not easy to control and protect. This is meaningful for low light level night vision technology.