Blocking artifacts reduction in JPEG compressed images using overcomplete wavelet representation

A simple, non-iterative, wavelet-based deblocking algorithm is proposed to reduce both the blocking and ringing artifacts in JPEG compressed images. The algorithm exploits the fact that block discontinuities are constrained by the dc quantization interval of the quantization table, as well as the behavior of the wavelet modulus maxima evolution across scales for singular image structures, to derive appropriate threshold maps at different wavelet scales. Simulation results have shown that the proposed algorithm is able to smooth out both block discontinuities and ringing artifacts while preserving true edges and textural information