Intra coding based on line-based prediction and transform

A novel line-based intra coding method is presented to improve the coding efficiency by both prediction and transform. Firstly, the spatial multi-prediction is performed line by line in horizontal or vertical direction within a macroblock using the pixels of the adjacent column or row as the reference, which improves the prediction accuracy by shortening the distance between the reference and current pixels. Secondly, on the basis of the original 4×4 discrete cosine transform (DCT), a 1×16 one-dimensional DCT is introduced as a candidate, and the transform is selected adaptively at the level of macroblock. Experimental results show that compared with the H.264/AVC, the proposed method reduces the bit rate by 6.7% approximately at the same peak signal to noise ratio (PSNR).