One Dimensional Transform For H.264 Based Intra Coding

Two dimensional (2D) discrete cosine transform (DCT) are widely used as the transform method in most of video and image coding area. In general, 2D separable DCT is effective for smoothed regions of which components are highly correlated. When the block to be transformed has directional edges or a few values, however, 2D transform can yield worse performance than 1D transform. This drawback is taken care of by 1D transform with line prediction this paper proposed. Line prediction between each coefficient ahead of 1D transform can reduce the repetitive residue. If it is applied with an appropriate scan order, therefore, it can bring additional bit saving of transform coefficients in entropy coding. By experiments, it is shown that the proposed framework including 1D transform and line prediction improves the overall rate-distortion (R-D) coding performance up to nearly 8% in comparison with H.264. Index Terms – video coding, directional one dimensional transform, line prediction