Color image enhancement based on local spatial homomorphic filtering and gradient domain variance guided image filtering

摘要

Image quality is affected by various factors, especially low illumination. We propose an image color enhancement method to improve the brightness and quality of images. First, we apply local spatial homomorphic filtering to images to improve the brightness and avoid edge block effect as well as image size limitation at the same time. Second, gradient domain variance guided image filtering is proposed for restrain noise amplification in image enhancement, which has better denoising and edge preservation. The above two algorithms are applied to the V-channel in the hue, saturation, value space to form a color image enhancement algorithm. This method not only improves the brightness and quality of low-illumination images but also avoids noise amplification after image enhancement. The experimental results prove that our proposed algorithm is superior to other methods in improving brightness and noise removal of low-illumination images. (C) 2018 SPIE and IS&T