Linear filtering techniques for reduction of blockiness

A computationally easy linear filter, namely, the odd harmonic suppression filter, is proposed to reduce blockiness in images. A simpler mapping from 1-D to 2-D is shown to be more effective for this filter, which produces the same or better improvement than a rectangular or circular filter but requires less computation. Also, use of a prefiltered codebook instead of prefiltering the input image is suggested in the context of a vector quantization coder, and is shown to be not only computationally easy but also subjectively superior