Total variation for the removal of blocking effects in DCT based encoding
Annapoorani Gothandaraman, Ross Whitaker, Jens Gregor · 2002
Quantization in block DCT based codecs can produce noticeable image artifacts. Anisotropic diffusion has been proposed as a remedy for removing such undesirable blocking effects. The main disadvantage of that approach is that artifacts near high-contrast image features are not adequately reduced. We propose an alternative non-linear method that reduces artifacts by minimizing the total variation of the reconstructed image in the vicinity of DCT block boundaries. This minimization is achieved via a level set formulation. Our experimental results indicate that the proposed method removes the blocking artifact effectively, producing an image with smooth level sets in the region interiors as well as near the true edges of the image.