Intra Coding With Adaptive Partial Reconstruction

Intra prediction improves coding performance by reducing inter pixel redundancy. However, to accommodate the use of block transforms, not all pixels can be predicted from reconstructed pixels that are located close to themselves. This causes prediction performance to suffer as pixel values further apart are less correlated. This paper presents additional intra coding modes designed with the goal of improving prediction performance. Experimental results show an average gain of about 2% in the key technical area software when the new modes are incorporated in the current 8×8 prediction modes. Since the new coding modes (8×8) are designed with transform size smaller than coding block size, the modes can also be useful when the source block is larger than the maximum transform size.