提出能同时消除亮度和反差分布不均匀现象的分块均值方差变换法, 重点对插值匀光法、MASK 匀光 法、同态滤波匀光法、Retinex 匀光法以及分块均值方差变换法的校正效果进行了实验比较。研究表明: 分块均值 方差变换法既能消除亮度分布不均匀现象, 又能消除反差分布不均匀现象, 而MASK 匀光法、插值匀光法、Retinex 匀光法只能解决亮度分布不均匀问题, 同态滤波匀光法仅能减弱亮度分布不均匀现象; 在匀光效果方面, 分块均 值方差变换法最好, MASK 匀光法次之, 插值匀光法紧随其后, 接下来是Retinex 匀光法, 同态滤波匀光法最差。

After the brief introduction of existing dodging methods, the piecewise mean-variance adjustment is presented for both brightness and contrast homogenization. Then, the focus of the paper is put on the experimental comparison among the results obtained by the following five algorithms: MASK dodging, interpolation dodging, homomorphic filtering dodging, retinex dodging, and piecewise mean-variance adjustment. The experiments indicate that the piecewise mean-variance adjustment can deal with non-uniform brightness and contrast in an image. MASK dodging, interpolation dodging and retinex dodging can eliminate the phenomenon of non-uniform brightness. However, homomorphic filtering dodging can only weaken the phenomenon of non-uniform brightness. The dodging performance ranks piecewise mean-variance adjustment, MASK dodging, interpolation dodging, retinex dodging, and homomorphic filtering dodging from the best to the worst, respectively.