针对目前图像增强算法应对非均匀光照环境的局限性, 提出了一种同时保持低照度区域和正常照度区域细节信息的图像亮度均衡算法。算法利用像素相邻频率和位置关系生成光照滤波器, 有效分离图像光照信息和反射细节信息。通过光照阈值划分光照亮暗区域进行低照度亮度补偿, 从而均衡图像亮度。实验结果显示, 相对于经典 NPEA算法, 图像平均峰值信噪比提升 15.4%、平均增强度提升 245.0%、平均亮度阶差下降 25.4%。因此, 本文算法能够在保持不同照度区域的细节信息的同时均衡亮度, 获得较好的视觉效果。

In order to overcome the limitation of current image enhancement algorithms for non-uniform illuminationimages, a brightness equalization algorithm is proposed to preserve the detail information in low illumination region and normal illumination region at the same time. The algorithm uses the adjacent frequency and position of pixels to generate illumination filter, so it can effectively separate illumination information and reflection information with de-tails. The illumination threshold is used to divide different illumination areas to compensate for low illumination brightness, so as to balance the image brightness. The experimental results show that compared with the classical naturalness preserved enhancement algorithm (NPEA), the average peak signal to noise ratio of the image in-creases by 15.4%, the average enhancement degree increases by 245.0%, and the average brightness step dif-ference decreases by 25.4%. The results of the proposed algorithm can maintain the details of different illumination areas while balancing the brightness and obtain a better visual effect.