JPEG压缩MRI图像对其图像边缘的影响

Effect of lossy JPEG compression on edge of MRI image

简要分析了有损JPEG压缩算法和几种经典的边缘提取算法;经对原始的和有损JPEG压缩的MRI图像的编程实验,分析了图像边缘的视觉效果和相异率,说明MRI图像经有损JPEG压缩后对图像的边缘和噪声都有所平滑改变和丢失;由于有损JPEG具有低通滤波的性质和本文所分析的几种经典的边缘提取算法具有高通滤波的性质,使MRI图像的边缘和噪声在JPEG压缩前后的差异随门限值的增大而变小。

This paper analyzes lossy JPEG compressing method and several classical algorithms of edge extraction in brief. The original MRI image and the compressed one with JPEG method are analyzed on their optical impressions and ratio of dissimilitude and the results show that the edges and the noises of the MRI image are smoothed and lost after being compressed. The JPEG method is lowpass and the edge extraction algorithms are anti-lowpass so the difference of the edges and noises between the original image and the compressed one diminishes with the augmentation of the threshold value.