减少分形编码方块效应的一种解决方案

分形图像编码方法通常把输入图像分割成小块,这在图像中引入了人为边缘,从而产生了恼人的块效应(特别是高压缩率下).这种块效应限制了基于块的编码方法的广泛应用,因此必须探索减少块效应的方法.目前已有2种方法,一种是构造分形变换时使用块重叠方案,另一种是结合小波分解方法.这里提出一种新的可选方法,主要利用双线性插值方法和分形编码的分辨率独立性,即解码可以按高于或低于原图像分辨率进行.实验表明,该方法能够减少方块效应.

A New Solution to Reduce Blocking Artifacts Introduced by Standard Fractal Methods

Fractal image coding techniques usually partition the input image into small range blocks. This artificially introduces boundaries into the image resulting in the unpleasant blocking artifacts in the decoded images especially at high compression rate. Because the effect is especially responsible for the restrictions of the block-based coders, the solutions must be sought to reduce this blockiness. Recently two possible schemes have been proposed by other researchers: One may try to use overlapping blocks in the fractal transform, and the other to employ the combined fractal wavelet approach. An alternative solution is proposed, which employs the bilinear interpolation techniques and the resolution independence of fractal coding, in the sense that an image can be decoded at higher or lower resolutions than the original. Experiments show that the proposed scheme can eliminate the blocking artifacts.