Ringing reduction in low bit-rate image subband coding using projection onto a space of paraboloids

摘要

This paper considers the well known problem of ringing distortion in subband coded images. Exploiting the fact that ringing artifacts are masked by edges and textures we propose a new method designed to remove all ringing distortion within the smooth image areas. The original image is used for classification purposes and the subband coded image is postprocessed using blockwise paraboloid fitting algorithms in the smooth image areas. Experimental results comparing subband coded images with and without application of the proposed method are presented. The results indicate that significant visual improvements can be made at the expense of a very small increase in bit-rat.