Abstract: Regardirer the problem of varying lighting in industrial Image processing pipeline system,this paper(introduces) a brightness normalization method of image by using conics fitting and statistical moments of histogram.First,it used conics fitting method to equalize the image’s brightness of each section,and then adjusted different illumination images to the same brightness level by applying the histogram statistics method.Thus,the strength of illumination no longer affects the test result.

Key words: image pipeline； varying lighting； conics fitting； statistical moments of histogram； brightness normalization；