Adaptive postprocessors with DCT-based block classifications

Abstract

In this paper, an adaptive postprocessor figured with discrete cosine transform (DCT)-based block classification to effectively remove the so-called blocky effect from compressed video sequences is proposed. The proposed DCT-based detection algorithms for both intraframes and interframes require much lower computation complexity than the spatial-domain approaches. In order to preserve the edge information, the adaptive postprocessor is also designed with a DCT-based edge detection mechanism such that a one-dimensional median filter can be adaptively adjusted to match with the edge orientation. Simulation results show that the proposed DCT-based detection algorithms accurately classifies smooth, edge, or nonsmooth blocks to help the adaptive postprocessor to effectively remove the blocky effect and sharply preserve the edge information.Index Terms-Adaptive median filter, transform coding, video coding, video signal processing.

Unified deblocking for discrete cosine transfer compressed images

“…10 The spatial adaptive filtering is probably the most thoroughly studied deblocking method, and various algorithms have been proposed. 7,11,15,17,[39][40][41][42][43][44][45][46][47] Obviously, the filtration of image can be performed in transform domain ͑either the DCT, discrete wavelet transform ͑DWT͒, or OWE domain͒. The algorithms in Refs.…”