Patent ID: 8942467
Filing Date: 2015-01-27
Classification: H04N

Abstract:
1. A method for reducing blocking artifacts, comprising: projecting each patch obtained from an input image onto a set of bases vectors to determine multiple representations for each patch, wherein the set of bases vectors are learned from a training image, and the bases vectors include a full basis vector, and one or two subspace bases vectors, wherein the training image is a step image; determining an optimal basis vector in the set of bases vectors for each patch according to the projection; applying a threshold to coefficients of the optimal basis vector to determine a filtered representation for each patch; generating a reconstructed patch using the filtered representation; and aggregating the reconstructed patches to produce an output image, wherein the steps are performed in a processor, further comprising: (a) initializing the set of bases vectors as a current set of bases vectors with the patches obtained from the training image; (b) determining a representation of each patch using the current set of basis vectors; (c) computing an error matrix for each current basis vector by using all other current basis vectors in the set of current bases vectors; (d) decomposing the error matrix only for the patches that use the set of current basis vector to obtain a truncated error matrix; (e) computing a largest eigenvalue and a corresponding eigenvector of the truncated error matrix; (f) assigning the eigenvector as an updated basis vector to be used as the current basis vector in a next iteration; and iterating the steps (a) through (f) for each basis vectors until a termination condition is reached.