将CCD(电荷耦合器件)单元等效成一个变阻RC积分电路，使图像中的光照效应分解为对光电势的影响和对光敏电阻的影响。当tτ时认为光照强度只影响光电势。而对于不满足这一条件的光照强度进行调整，使非均匀照度图像中的低照度部分得以恢复，而正常照度部分和高光部分基本保持不变。将该模型应用于增强非均匀照度图像的常规算法之前，可收到较好的效果。

The CCD cell is equalized as a variable resistance RC integral circuit, the lighting effect on the image is decomposed into pair impact of photoelectric potential and photosensitive resistance. When t>>τ, the illumination affects only the photoelectric potential, otherwise to be adjusted, so that, the parts of low illumination can be restored, the normal and high-light parts can be maintained almost. It can achieve good results, this model is applied to the conventional method of uneven illumination enhancement before.