Decoder side motion vector derivation for inter frame video coding

ABSTRACT In this paper, a decoder side motion vector derivation scheme for inter frame video coding is proposed. Using a template matching algorithm, motion information is derived at the decoder instead of explicitly coding the information into the bitstream. Based on Lagrangian rate-distortion optimisation, the encoder locally signals whether motion derivation or forward motion coding is used. While our method exploits multiple reference pictures for improved prediction performance and bitrate reduction, only a small template matching search range is required. Derived motion information is reused to improve the performance of predictive motion vector coding in subsequent blocks. An efficient conditional signalling scheme for motion derivation in Skip blocks is employed. The motion vector derivation method has been implemented as an extension to H.264/AVC. Simulation results show that a bitrate reduction of up to 10.4 % over H.264/AVC is achieved by the proposed scheme

Inter-prediction methods based on linear embedding for video compression

International audienceThis paper considers the problem of temporal prediction for inter-frame coding of video sequences using locally linear embedding (LLE). LLE-based prediction, first considered for intra-frame prediction, computes the predictor as a linear combination of K nearest neighbors (K-NN) searched within one or several reference frames. The paper explores different K-NN search strategies in the context of temporal prediction, leading to several temporal predictor variants. The proposed methods are tested as extra inter-frame prediction modes in an H.264 codec, but the proposed concepts are still valid in HEVC. The results show that significant rate-distortion performance gains are obtained with respect to H.264 (up to 15.31% bit-rate saving)