Rotated Orthogonal Transform (ROT) for Motion-Compensation Residual Coding

• Published in: IEEE transactions on image processing Vol. 21; no. 12; pp. 4770 - 4781
• Main Authors: Gu, Zhouye, Lin, Weisi, Lee, Bu-Sung, Lau, Chiew Tong
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-12-2012; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Coding, codes; Detection, estimation, filtering, equalization, prediction; Discrete cosine transforms; Exact sciences and technology; Image coding; Image processing; Information, signal and communications theory; L1-norm minimization; Minimization; motion-compensation residual (MC-residual); orthogonal constraints; Signal and communications theory; Signal processing; Signal, noise; Sparse matrices; Telecommunications and information theory; transform coding; Vectors; Video coding; Video coding; Performance evaluation; L1-norm minimization; Orthogonal matrix; Image processing; Data compression; L1 approximation; motion-compensation residual (MC-residual); orthogonal constraints; Image compression; Video codecs; Video signal processing; Orthogonal transformation; Constrained optimization; Image coding; Transform coding; Residual impurity; Signal processing; Motion compensation; Discrete cosine transforms
• ISSN: 1057-7149; 1941-0042
• DOI: 10.1109/TIP.2012.2206045

Discrete cosine transform (DCT) is the orthogonal transform that is most commonly used in image and video compression. The motion-compensation residual (MC-residual) is also compressed with the DCT in most video codecs. However, the MC-residual has different characteristics from a nature image. In this paper, we develop a new orthogonal transform-rotated orthogonal transform (ROT) that can perform better on the MC-residual than the DCT for coding purposes. We derive the proposed ROT based on orthogonal-constrained L1-Norm minimization problem for its sparse property. Using the DCT matrix as the starting point, a better orthogonal transform matrix is derived. In addition, by exploring inter-frame dependency and local motion activity, transmission of substantial side information is avoided. The experiment results confirm that, with small computation overhead, the ROT is adaptive to change of local spatial characteristic of MC-residual frame and provides higher compression efficiency for the MC-residual than DCT, especially for high- and complex-motion videos.