Abstract: The TV system of opto-electric tracking and measuring device, affected by natural conditions, often cannot capture focused images. It is prone to extremely low contrast image. This paper presents a gray-scale transform method with the difference of neighbor pixel to determine the segment points. First, by calculating the difference between the gray scale pixel 55 neighborhoods, ND is taken as the sum of the minimum 12 values. Then, on the basis of a large number of experiments, the appropriate threshold T is determined, with which the ND is compared to determine the edge pixel in the image range. Finally, according to the scope, the segment points of segmentation gray-scale transform formula are determined. The results show that after processed by this algorithm, the contrast is 18.79 times of the original image which is 1.19%, 6.97 times of the histogram equalization and 41.41 times of the histogram specification. The contrast has reached 22.36%, and the image histogram is also highlighted by the single peak to a more balanced state. The algorithm has obtained good data and visual effects, and met the requirements of TV system, which has been used in optical tracking device. The algorithm has good practical value.