A pruning algorithm is proposed to reduce the encoding bits for the map information of residual coefficients in H.264. Video sequences are predicted
transformed
quantized
and scanned. Then residual coefficients obtained from scanning are divided into linear groups
and then the groups are pruned out using the rate-distortion optimization(RDO)sense. Furthermore
the pruning results of each macroblock with different quantization steplengths are calculated in a given range. Finally the remaining coefficients with the minimal rate-distortion cost are encoded and transformed. Experimental results show that the proposed algorithm has better RD performance than the residual coding method in H.264 at the relatively high bitrates. The proposed algorithm gains an 0.9 dB increase on the peak signal to noise ratio( PSNR)at the same bitrate
or equivalently
a 17% rate saving at the same PSNR. Moreover
the proposed algorithm does not change the bit-stream structure of H.264
and is compatible with the H.264 standard.
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references
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