基于小波和分块同态滤波的变光照图像增强方法

Method of Variable Illumination Image Enhancement Based on Wavelet and Block Homomorphic Filtering

为提高变光照情境下图像质量,针对部分图像存在亮度不均、对比度低的问题,提出了基于小波与分块同态滤波的图像特征增强算法.首先将图像从原始色彩空间转换为HSV空间,以图像亮度分量V作为增强对象;然后利用小波变换代替分块同态滤波中的传统傅里叶变换对亮度分量分解,并对小波分解的子图像进行分块后进行高通滤波处理,对滤波后的图像进行合并、重构从而实现特征增强.实验结果表明,本文算法对变光照情境下的图像增强效果明显,有效校正了图像的整体亮度,显著提高了图像的细节对比度.

In order to improve the image quality under variable lighting conditions, an image enhancement algorithm based on wavelet and block homomorphic filtering is proposed to solve the problems of uneven brightness and low contrast of some images under variable lighting conditions. First, the image is converted from the original color space to HSV space and the component of image brightness V is used as the enhancement object. Then, the wavelet transform is adopted to replace the traditional Fourier transform in the block homomorphic filtering to decompose the luminance component, and the decomposed sub-images are divided into blocks and processed by high-pass filtering. Meanwhile, the filtered images are merged and reconstructed to achieve the characteristics enhancement. The experimental results show that the proposed algorithm in this paper has a significant effect on image enhancement under variable lighting conditions, the overall brightness of the image is corrected, and the detail contrast of the image is improved significantly.