Title :
A postprocessing technique for block effect elimination using a perceptual distortion measure
Author :
Derviaux, C. ; Coudoux, F.X. ; Gazalet, M.G. ; Corlay, P. ; Gharbi, M.
Author_Institution :
Univ. de Valenciennes, France
Abstract :
One of the drawbacks of the discrete cosine transform (DCT) is visible block boundaries due to coarse quantization of the coefficients. In this paper, an algorithm for the reduction of blocking artifacts is presented. The proposed method allows to produce higher quality reconstructed images by adaptively filtering the video signal according to the noise visibility. A visual model is therefore defined for predicting the block edge visibility across each picture of the coded sequence. This model that accounts for the perceptual characteristics of the block distortion is described. Experimental results are presented for low bit-rate coded sequences. They show that the postfiltering operation yields significant results with enhanced visual quality
Keywords :
adaptive filters; data compression; digital filters; discrete cosine transforms; edge detection; image reconstruction; image sequences; interference suppression; optical noise; transform coding; video coding; adaptive filtering; block distortion; block edge visibility; block effect elimination; blocking artifacts; coarse quantization; coded sequence; discrete cosine transform; low bit-rate coded sequences; noise visibility; perceptual distortion measure; postprocessing technique; reconstructed images; video signal; visible block boundaries; visual model; visual quality; Discrete cosine transforms; Distortion measurement; Finite impulse response filter; Frequency; Humans; Nonlinear distortion; Video sequences; Visual effects; Visual perception; Visual system;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 1997. ICASSP-97., 1997 IEEE International Conference on
Conference_Location :
Munich
Print_ISBN :
0-8186-7919-0
DOI :
10.1109/ICASSP.1997.595423