An all-zero block detection algorithm based on linear classifiers is proposed to reduce the complexity of the H.264 video encoder and to improve the lower detection rate of common all-zero block detection methods. Five effective features are selected according to the characteristics of the encoder. Then the algorithm uses two different linear classifiers to separate all-zero blocks from non-all-zero blocks based on the encoding situation of the reference block. The training samples are selected from different videos
and the weights of the features and the thresholds of all-zero block detection under different quantization parameters are trained using the Fisher criterion. The thresholds under different quantization parameters are fitted into a quadratic polynomial of the quantization parameter using the least square method. Experimental results show that the proposed algorithm achieves better detection rate than that of other algorithms
and can effectively shorten the encoding time while maintaining the video quality.
关键词
Keywords
references
XIE Zhengguang,LIU Yong,LIU Wenjun,et al.A general method for detecting all-zero blocks prior to DCT and quantization [J].IEEE Transactions on Circuits and Systems for Video Technology, 2007, 17(2):237-241.
PAN Feng, LIN Xiao, RAHARDJA S, et al.Fast mode decision algorithm for intraprediction in H. 264/AVC video coding [J].IEEE Transactions on Circuits and Systems for Video Technology, 2005, 15(7):813-822.
WU Dajun,PAN Feng,LIM K P,et al.Fast intermode decision in H. 264/AVC video coding [J].IEEE Transactions on Circuits and Systems for Video Technology, 2005, 15(7):953-958.
ZHU Ce,LIN Xiao,CHAU L,et al.Enhanced hexagonal search for fast block motion estimation [J].IEEE Transactions on Circuits and Systems for Video Technology, 2004,14(10):1210-1214.
HUANG Hua,CHENG Hui,LIU Dingding.A fast motion estimation algorithm for motion complexity decision [J].Journal of Xi'an Jiaotong University,2009,43(10):81-84.
SOUSA L A.General method for eliminating redundant computations in video coding [J].Electronics Letters, 2002, 36(4):306-307.
MOON Y H,KIM G Y,KIM J H.An improved early detection algorithm for all-zero blocks in H. 264 video encoding [J].IEEE Transactions on Circuits and Systems for Video Technology, 2005, 15(8):1053-1057.
ZHANG Maojun,ZHOU Tao,WANG Wei.Adaptive method for early detecting zero quantized DCT coefficients in H. 264/AVC video encoding [J].IEEE Transactions on Circuits and Systems for Video Technology, 2009, 19(1):103-107.
CHANG Y, KIM M,HAHM A, et al.Fast all-zero block detection based on classification approach [C]∥ Proceedings of 9th Biennial Conference of the Australian Pattern Recognition Society on Digital Image Computing Techniques and Applications. Los Alamitos, CA, USA: IEEE Computer Society,2007:267-273.
王嵩,薛全,张颖.基于 H. 264/AVC 整数变换的全零块检测方法 [J].计算机工程与应用, 2004, 40(19):75-77.
WANG Song,XUE Quan,ZHANG Ying.All-zero block detection based on H.264/AVC integer transform [J].Computer Engineering and Applications, 2004, 40(19):75-77.