This paper presents a new adaptive post-processing algorithm for ringing artifact reduction after image interpolation (upsampling). The algorithm is based on the concept of total variation (TV) for ringing control. It uses known TV of the blocks of the low-resolution image. Conditional gradient, subgradient and projection subgradient methods for this algorithm are considered and analyzed. A test set of 181300 overlapping 11x11 blocks of real images was used for local algorithm optimization and analysis. Local conditional gradient method shows the best objective and subjective results.
Andrey S. Krylov, Andrey V. Nasonov