A postprocessing technique for block effect elimination using a perceptual distortion measure

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 widely described in the main section of the paper. Then experimental results are presented for low bit-rate coded sequences ; they show that the postfiltering operation yields significant results with enhanced visual quality.