关键词: 路面病害, 图像阴影, 图像增强, 自动检测

Abstract: In pavement distress automatic detecting，there exist many problems to disturb the result of measurement.The main factor is the shadow of image，which is caused by the measure car or mountain，trees.How to eliminate the shadow from the images is the key step for automatic pavement distress detection system.This paper introduces an algorithm to remove the shadow from the pavement images.The algorithm is based on difference threshold.Firstly set up an illuminative background subset for the image.Then can get the whole background of the image by interpolation and binarization.By the aid of the background image，can remove the shadow from the pavement images easily.Analyze the validity and rationality by an example.But only discuss the regular shadow images，and those like the shadow image caused by trees etc，for which the shape is irregular，are needed to be studied further more.

Key words: pavement distress, image shadow, image enhancement, automatic detection