Adaptive orthogonal transform for motion compensation residual in video compression

Abstract

Among the orthogonal transforms used in video and image compression, the Discrete-Cosine-Transform (DCT) is the most commonly used one. In the existing video codecs, the motion-compensation residual (MC-residual) is transformed with the DCT. In this paper, we propose an adaptive orthogonal transform that performs better on the MC-residual than the DCT. We formulate the proposed new transform based on L1-Norm minimization with orthogonal constraints. With the DCT matrix as the starting point, it is guaranteed to derive a better orthogonal transform matrix in terms of L1-Norm minimization. The experimental results confirm that, with little side information, our method leads to higher compression efficiency for the MC-residual. Remarkably, the proposed transform performs better in the high/ complex motion situation. © 2011 Springer-Verlag Berlin Heidelberg.