Video signal decoding apparatus with artifact reduction

Claim 2

A video signal decoding apparatus for decoding a coded video signal produced by encoding an input video signal with an input video signal with an encoding apparatus comprising: a partitioning means for partitioning each frame of said input video signal into smaller blocks of pixel data; a transform coding means for transforming said partitioned blocks into blocks of transformed coefficients, a quantization means for quantizing said transformed coefficients to produce transformed coefficients; and a run-length and variable coding means for run-length and variable length coding said quantized coefficients to produce a coded bit, said video signal decoding apparatus comprising: a variable length and run-length decoding means for decoding said coded bit to reconstruct said blocks of quantized coefficients; an inverse quantization means for inverse quantizing said blocks of reconstructed quantized coefficients; an inverse coding means for transforming said inverse quantized blocks of reconstructed quantized coefficients to produce a decoded block; an edge block detection means for determining whether said decoded block is classified as an edge block or not; and an adaptive edge enhancement filter means for removing the distortion from said decoded block when said decoded block is determined as an edge block by said block edge detection means.

Claim 3

A video signal decoding apparatus as claimed in Claim 2, wherein said edge block detection means comprises: a first calculating means for calculating an average value of said decoded block, a second calculating means for calculating a maximum value and a minimum value of said decoded block, a third calculating means for calculating a first absolute difference value between said average value and said maximum value; a fourth calculating means for calculating a second absolute difference value between said average value and said minimum value; and a determining means for determining that said decoded block is an edge block when either of said first and second absolute difference values is greater than a predetermined value, and otherwise determine that said decoded block is a non-edge block.

Claim 4

A video signal decoding apparatus as claimed in Claim 2, wherein said adaptive edge enhancement filter means performs convolution on a pixel by pixel bases on the decoded edge block with an adaptive averaging filter mask by comparing a difference between every neighboring pixel of said pixel and said pixel to be convolved with a second predetermined value; and averaging by said neighboring pixel when said difference is judged as smaller than said second predetermined value.

Claim 5

A video signal decoding apparatus as claimed in Claim 2, wherein said encoding apparatus further compares a first motion compensation means for removing the temporal redundancy and likewise in said partitioned blocks before being transformed by said transform coding means; and said video decoding apparatus further comprising a second motion compensation means for performing an inverse motion compensation of said reconstructed block before being processed by said edge block detection means.

Claim 6

A video signal decoding apparatus for decoding a coded video signal, said removing ringing noise in a decoded image pixel data comprising: a decoding means for decoding said coded video signal to reconstructed image pixel data and partitioning said reconstructed image pixel data into blocks of pixels; a ringing noise source detection means for comparing said reconstructed image pixel data with a predetermined value to detect the source and location of the ringing noise in a block by block basis in said reconstructed image pixel data and to produce a status signal; a memory means for said status signal therein; and a ringing noise filter means for filtering the ringing noise from said reconstructed image pixel data based on said status signal.