摘要:
该文提出了一种新的保边缘滤波算法,该算法根据图像区域的局部方差大小动态调整滤波器的支撑集的大小。方差越大的区域,说明其高频分量越多,支撑集就越小。为了能在滤波的同时尽量保护图像边缘,该算法还根据像素点和中心点的方向矢量同支撑集内的平均梯度的夹角把支撑集内的像素点分成不同的集合,并给予沿着图像边缘的集合以较大的加权值以及垂直边缘方向的集合小的加权值,从而保证了边缘不模糊。从滤波结果看,经该算法处理过的图像的峰值信噪比(PSNR)明显高于中值滤波器处理过的图像,对细节比较丰富的图像,高于近 3dB。
Abstract:
In this paper, a new edge-reserve filtering algorithm is presented. It adaptively adjusts the size of the filters supporting area according to the local variance of the interested area. The bigger the local variance is, which means the more high frequency texture information is contained in this area, the smaller the support area will be. In order to protect the edges of the image when it is filtered, this algorithm will divide the pixels in its supporting area into several groups according to the angle between its direction and the mean gradient of this area. By this way, pixels along the content edges will be given a bigger weight factors than pixels that are vertical to the image edge. Thus protect the edges from being blurred by the filtering process. The simulation results show that this algorithm is better than median filter both in terms of PSNR values and subjective image qualities. For pictures that are rich in texture information, the PSNR gain could reach 3dB higher.