基于CIELAB空间的开关型矢量中值滤波器

A Switching Vector Median Filter Based on CIELAB Color Space

矢量中值滤波器VMF(Vector median filter)是一种经典和高效的矢量滤波器,主要用于消除彩色图像中的脉冲噪声.然而VMF没有区分细线条和噪声的能力,往往把细线条当成噪声而过滤掉.本文先将彩色图像从RGB空间变换到均匀颜色空间CIELAB中,然后模仿Laplacian算子,提出一个用于检测彩色图像中的脉冲噪声的算法,并结合传统的VMF构造出一个新颖的开关型矢量中值滤波器.实验表明,新的滤波器不仅能有效地保护细线条和边界等细节信息,而且其滤波性能也明显胜过传统的VMF和一些经典的、及最近开发的矢量滤波器.

Vector median filter （VMF） is a kind of traditional and highly effective vector filter which is mainly used to remove impulsive noise from color images. However,it fails to distinguish thin lines and boundaries from impulsive noise, and usually filter them out because it regards them as some noise. In this paper the original RGB-image is first converted to the CIELAB space,then by means of imitating Laplacian operators,a new color impulse detector is presented. Combining this color impulse detector with the traditional VMF,a new kind of switching vector median filter （LABSVMF）,is proposed. The experimental results show that the proposed filter,not only can effectively preserve the fine details,but also provides better filtering performance compared to the traditional VMF and some of the representative vector filters and recently developed vector filters.