Post-processing coding artefacts for JPEG documents

International audienceCoding artifacts, including ringing and blocking artifacts, are often introduced when compressing document images by using the JPEG standard. Theseartifacts can make the documents annoying and severely impact the visual perception of document content. Although a number of methods have been presented to deal with coding artifacts, most of them are dedicated to natural images. A few works have been investigated to work on document content. The current work is an attempt to fill this lack. In contrast to all the approaches taken by previous works, we propose to post-process the coding artifacts by compensating quantization noise for the decoder. To this aim, an iterative algorithm is presented to estimate the quantization noise. The estimated noise is then used to reconstruct the image with better quality. A number of experiments have been conducted to show the efficiency of the proposed methodin comparison with the state-of-the-art methods