基于视觉特性的Riemann-Liouville分数阶图像增强

为了解决Grünwald-Letnikov分数阶微分算法对彩色图像增强容易产生色彩失真以及传统方法增强效果不明显的问题，在分数阶微分视觉模型的基础上提出了一种基于Riemann-Liouville(R-L)分数阶微分的数字图像增强算法。首先讨论了数字图像的分数阶微分视觉模型；接着在R-L分数阶微分方程的基础上构造了8个方向上的分数阶微分增强模板；并讨论了这些微分增强模板的数值运算规则；并在HSI色彩空间对I分量进行分数阶微分实现彩色图像的增强处理。实验表明本文方法具有非线性特性，对图像增强效果明显，且增强

A Riemann-Liouville Fractional Differential Image Enhancement Algorithm Based on Human Visual Characteristics

In order to overcome the defects that enhancement effects of classical approaches are not obvious and the Grünwald-Letnikov(G-L) fractional differential operator could make color image distortion, a fractional differential image enhancement algorithm based on fractional-order receptive field model for gray and color image enhancment was presented.First, fractional-order receptive field of digital image was discussed.Next, a fractional-order differential convolution mask for image enhancement was constructed according to R-L fractional partial differential equation and its numerical implementation on eight directions was discussed in detail. This algorithm was applied in HSI color space and only the Intensity(I) component was processed for color image enhancement.The experiments showed that the proposed algorithm is non-linear and it can obviously enhance gray and color images.The enhanced images have no color distortion.