Reducing JPEG distortion

Reducing JPEG distortion

http://adage.berkeley.edu/~amnon/ EncodingEnhance/EncodingEnhance.html

Filtering and edge enhancement have been applied to restoring images that have been distorted due to lossy image compression. But these techniques have ignored a feature of digital compression--the fact that the sender has access to both the original and the distorted images, enabling the encoder to transmit information specifying the regions where the enhancement was successful. On this Web page, Amnon Silverstein and Stanley Klein focus on methods for reducing the distortion introduced by the JPEG compression system and illustrate the techniques visually.