基于结构的无窗口图像滤波器及其应用  

A structure based windowless image filter and its applications

作　　者：宋焕生[1] 王养利[2] 吴成柯[2] 

机构地区：[1]长安大学信息工程学院,陕西西安710064 [2]西安电子科技大学通信工程学院,陕西西安710071

出　　处：《西安电子科技大学学报》2005年第5期813-817,共5页Journal of Xidian University

基　　金：国家自然科学基金资助项目(60272050)

摘　　要：无窗口非线性图像滤波器利用阈值分解将灰度图像分解为一组二值图像,然后在二值图像上直接进行不涉及窗口的滤波操作,二值图像中的图像结构可以很容易地分割开来,因此,图像滤波就可针对相对独立的图像结构,而不是单独的图像像素.该滤波器的直接实现需要很大计算量,无法满足实用要求.为此,文中提出两个实现方案,一个是利用灰度直方图减少阈值分解中二值图像的数量,另一个是利用灰度图像的等高线描述阈值分解后二值图像中的图像结构,从而省去了图像阈值分解和图像层叠重建的过程.将无窗口非线性图像滤波器用于汽车牌照识别中的牌照定位,获得了较好效果.The realization and application of a windowless nonlinear image filter are studied. In the windowless nonlinear image filter, an input gray-scale image is transformed into a group of binary parts by threshold decomposition, and then nonlinear windowless filter operation is performed on these binary images. As it is usually very easy to segment image structures in a binary image, so we can handle the image based on meaningful image structures instead of distinct image pixels. But the original windowless filter algorithm needs very heavy computation, so it is unpractical. To overcome this drawback, two solutions are given： 1 ）by reducing the amount of the binary images of threshold decomposition, one can cut down a lot of computation of threshold decomposition and reconstruction; 2）in image structure analysis, instead of the binary images, the contour lines are used, so the complex threshold decomposition and reconstruction process are bypassed. As a real application, the results of car license plate location by the new filter are reported.

关 键 词：图像滤波 非线性滤波 图像窗口 汽车牌照识别 

分 类 号：TN919.8[电子电信—通信与信息系统]