在图像平滑处理过程中,如何设计保持图像边缘和纹理细节的数字图像去噪滤波器一直是人们关注的热点问题。本文在统一描述数字全变差滤波算法(DTV)和数字双边全变差算法(DBTV)的滤波机制的基础上,利用图像像素间的近一远程相关性,分别定义近程相关性和远程相关性两个度量,建立了一种非局部图像滤波自适应双边加权机制,提出一种同时适合高斯噪声和脉冲噪声的非局部数字全变差滤波算法(NLTV)。实验验证了新算法在抑制噪声的同时具有较好的边缘细节和纹理保持性能。
How to design digital image denosing filters with good ability of preserving edge and texture information is an international and popular issue in image processing. The unified filtering mechanism of digital TV filter (DTV) and digital bilateral TV filter (DBTV) is described firstly, and then a novel non-local adaptive bilateral filtering mechanism is established. The definition of pixel' s short dependence and long dependence measures are given, and a new non-local digital TV filter (NLTV) is proposed which can deal with Gaussian noise and impulse noise respectively. Experiments show that our proposed algorithm has quite good ability of noise suppressing as well as edge and texture preserving.