Intra Prediction by Averaged Template Matching Predictors

Intra prediction is an effective tool for coding still images and intra pictures in video. The H.264/AVC video compression standard uses extrapolation of the reconstructed pixels surrounding the target block to be coded to form the sample predictor block. Our previous paper augmented this conventional intra prediction method with sample predictor blocks generated using pixel based texture synthesis by template matching methods. This paper describes further improvements and refinements of the sample predictor block creation method. Multiple candidate sample predictor blocks were created using template matching. A weighted average of the multiple candidates then formed the final sample predictor block. Improvements in coding efficiency by more than 15% in bitrates were achieved by this refined method compared to the conventional intra prediction. The impact of the search window and the different template shapes used in the template matching method was also studied and presented.