Blocking artifact reduction in frequency domain

A novel frequency domain technique for image blocking artifact reduction is presented in this paper. For each block, its DC and AC coefficients are recalculated for artifact reduction. To achieve this, a closed form representation of the optimal correction of the DCT coefficients is produced by minimizing a novel enhanced form of the Mean Squared Difference of Slope (MSDS), for every frequency separately. This correction of each DCT coefficient depends on the eight neighboring coefficients in the subband-like representation of the DCT transform and is constrained by the upper and lower bound of the quantized DCT coefficients. Experimental results illustrating the performance of the proposed method are presented and evaluated.