Reduction of blocking artifacts by a modeled lowpass filter output
This paper proposes an algorithm for the reduction of blocking artifacts in the transform coded images and videos. The algorithm is based on the filtering of block boundaries. But, the proposed technique is not the actual filtering in the sense that the output is not obtained by multiplying the pixel values with the filter coefficients. Instead of filtering the pixel values through the filter coefficients, the output of the filter is modeled as a typical step response function of the lowpass filter or a functions with similar shapes. Then the blocky signal is just replaced by the modeled output signal which is generated by the library function such as exp or sin. The algorithm can be easily implemented by a lookup-table and very few multiplications, while the objective and subjective performance is comparable to those of other algorithms based on the conventional filtering and POCS (projection onto convex sets).