Research On Shadow Removal Algorithm Based On Region Matching

Shadow is caused by objects blocking the light source during shooting.It will degrade the image to varying degrees.For example,it will cause interference to the information extracted from the target image,reduce the optical information contained in the image,have a negative impact on the speed and accuracy of image interpretation,and affect the application and quantitative analysis of the image.Therefore,the study and removal of shadow in the image is of great significance.The main content of this paper is the shadow detection and removal algorithm based on a single image.The basic property of shadow is the theoretical basis for the study of shadow detection algorithm.The premise of shadow removal is shadow detection.The quality of shadow detection algorithm can directly affect the results of shadow removal algorithm.This paper draws on the idea that brightness information is very important when using ratio graph method for shadow detection.Considering that the shadow area of a single image is mostly a large black connected area,which leads to the difference between the brightness value of the shadow area and the non-shadow area,a shadow detection algorithm combining average brightness and region growth is proposed.After the realization of the shadow detection algorithm,the paper mainly introduces the shadow removal based on the region matching algorithm.Different from the traditional shadow removal algorithm,the algorithm proposed in this paper is to segment the image texture before matching.Firstly,the shadow and non-shadow regions are divided into several smaller regions,the texture features and spatial distance between each region are extracted,and then each region is matched.Finally,the shadow image is restored using the light transfer algorithm.This algorithm can not only process the shadow image with complex texture,but also ensure that the information elements in the shadow area return to normal shadow-free effect and ensure that the image is in line with the visual connectivity.