关键词: 随机森林, 快速编码, 离线训练, CU划分, HEVC

Abstract: To reduce the coding computational complexity of the quadtree structured Coding Unit（CU） partition process forintra-framein High Efficiency Video Coding（HEVC）, a fast CU splitting algorithm based on Random Forest Classifier（RFC） is proposed. The algorithm includes two parts: model off-line training and CU fast coding algorithm. In the process of off-line training, a RFC model is constructed, where the optimal partition result of current CU is utilized as class label（+1, －1）, and the contrast, the inverse different moment and the entropy information of current CU are treated as feature vectors. In the process of encoding, characteristic attribute values of current CU are extracted, then, a trained RFC model is used to predict the class label. The experimental results show that the proposed algorithm can save 45.18% coding time on average under the premise of guaranteeing the coding quality compared with HEVC standard algorithm.

Key words: random forest, fast encoding, offline training, CU partition, High Efficiency Video Coding（HEVC）