Enhancement of surface defect images on copper plates under non-uniform illumination
摘要
Aiming at the problem that the image of defects on the surface of copper plate is easily affected by non-uniform illumination, which results in reflections and brightness distortion and makes it difficult to apply the image to detection, an enhancement method for the image of defects on the surface of copper plate under non-uniform illumination scenario is proposed. Firstly, the light components in the image are extracted, chunked and then optimized according to the brightness of different chunks. Based on the chunking, adaptive gamma correction is performed to adjust the overall brightness of the image. Then, Top-Hat transform is used to enhance the defective regions in the image, and finally the images before and after Top-Hat transform are fused to obtain the final image. The experimental results show that the information entropy of the enhanced image is improved by 10.51%, 5.29%, and 2.89% in three types of defects, namely scratches, scratches, and holes, respectively. Compared with other image enhancement algorithms, the proposed algorithm can effectively inhibit the reflection of the defects on the surface of the copper plate, improve the quality of the image and enhance the defective regions in the image.