梯度矢量扩散控制实现边缘保持的彩色图像去噪  

Edge preserving denoising of color image through controlling the gradient vector

作　　者：贾迪[1] 孟祥福[1] 张一飞[2] 董娜[1] 李思慧[1] 

机构地区：[1]辽宁工程技术大学电子与信息工程学院 [2]东北大学信息科学与工程学院

出　　处：《中国图象图形学报》2014年第4期493-501,共9页Journal of Image and Graphics

基　　金：国家自然科学基金项目(61003162);辽宁省教育2013年杰出青年学者成长计划(LJQ2013038)

摘　　要：目的在图像的获取过程中,由于受到噪声等因素影响,可能导致图像质量下降,给后期处理带来困难,为此提出一种梯度矢量扩散控制实现边缘保持的彩色图像去噪方法。方法首先分析了彩色图像因灰度化带来的信息损失,为了更好地利用彩色图像信息,构造了RGB空间下的梯度矢量计算方法。其次分析了噪声邻域梯度矢量与边缘邻域梯度矢量间区域性结构差异,并指出现有扩散方程的不足,给出一种控制扩散矩阵的获取方法。最后通过推导矢量图像的边缘函数,给出了RGB空间下的PM方程,分解该模型去除法向扩散,并结合控制扩散矩阵改进边缘停止函数,以此获得更好的矢量扩散控制。结果实验结果表明,采用这种方法得到的处理结果有较高的信噪比,验证了该方法的有效性。结论本文方法能够在去噪的同时,较好地保持图像对比度与边缘信息,具备一定的实用性。Objective Due to the impact of the equipment and the environment, poor quality images could be generated in- evitably in the process of image acquisition, which makes the later processing more difficult. In this paper, an edge preser- ving denoising method for color images through a controlling gradient vector is proposed. Method In order to make better use of the color image information, information loss is analyzed by transforming color images to gray image in the first step. Furthermore, the calculation method of a gradient vector in RGB space is proposed. Second, by analyzing regional structure differences of the noise gradient vector in a neighborhood and the edge gradient vector in a neighborhood, the in- adequacy with diffusion equation is pointed out, and a method for controlling the diffusion matrix is proposed. Finally, PM equation in RGB space is proposed through the edge function derived by vector images, normal diffusion is removed by de- composition of model and improved edge stopping function with the controlling the diffusion matrix can make better con- trol. Result The results show the proposed method has higher signal to noise ratio, and the effectiveness of it is veri- fied. Conclusion This method can denoise image, and it could keep the image contrast and edge information at the same time, so it has some practicability.

关 键 词：图像去噪 梯度矢量 扩散方程 PM模型 方向扩散 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]