Template matching methods have been shown to offer hit rate savings of up to 15% when used for in-loop prediction in compression. Yet the required nearest-template search process results in prohibitive complexity. Hen...
详细信息
ISBN:
(纸本)9780992862633
Template matching methods have been shown to offer hit rate savings of up to 15% when used for in-loop prediction in compression. Yet the required nearest-template search process results in prohibitive complexity. Hence, in this paper we use approximate nearest neighbor search methods to successfully address this drawback of template matching methods. Our approach uses a template index that is updated during the decoding process, yet the incurred overhead pays off in reduced nearest-template search complexity, resulting in a significant gain in template search complexity. Rate-distortion experiments further indicate that there is no rate-distortion penalty resulting from our proposed approximate template search method, and in fact a small gain of 0.1 dB is observed.
Context-based adaptive variable length coding (CAVLC) for the H.264/advanced video coding (AVC) standard was originally designed for lossy video coding, and as such does not yield adequate performance for lossless vid...
详细信息
Context-based adaptive variable length coding (CAVLC) for the H.264/advanced video coding (AVC) standard was originally designed for lossy video coding, and as such does not yield adequate performance for lossless video coding. In this paper, we propose an improved CAVLC for lossless intra-coding by considering the statistical differences in residual data between lossy and lossless coding. From experimental results, we confirm that the proposed method provides approximately 9% bit saving in terms of a compression ratio compared with the current H.264/AVC fidelity range extensions high profile.
intra-coding plays an important role in video coding schemes and it has become a hot research topic of the next generation video coding standard. In this paper, we propose two techniques to improve the efficiency of t...
详细信息
ISBN:
(纸本)9781424479948
intra-coding plays an important role in video coding schemes and it has become a hot research topic of the next generation video coding standard. In this paper, we propose two techniques to improve the efficiency of the prediction and the transform, respectively, for intra-coding. First, we introduce an overlapped block intra-prediction (OBIP) method, which makes use of the intra directional prediction modes of neighboring blocks as well as the mode of the current block. A position dependent weighted sum of several possible predictors will be treated as the final prediction. Second, we propose a multiple-model Karhunen-Loeve transform (MMKLT) technique to further improve the mode dependent directional transform (MDDT) method. More than one KLT will be trained offline for each intra-prediction mode based on residual variances. Experimental results indicate that the proposed two methods together can achieve an average bit-rate reduction about 11% compared with H. 264 or 5% compared with MDDT in all-intracoding.
Rate control in H.264/AVC aims to achieve the best trade-off between encoding quality and bandwidth while satisfying the buffer restriction. Due to the improving efficiency of infra-only rate control, we propose an ef...
详细信息
ISBN:
(纸本)9781424456536
Rate control in H.264/AVC aims to achieve the best trade-off between encoding quality and bandwidth while satisfying the buffer restriction. Due to the improving efficiency of infra-only rate control, we propose an effective rate control scheme for intra-only encoding. The proposed scheme employs a novel Rate-Distortion (RD) model, a new complexity measure, a precise Quantization Parameter (QP) calculation method, and a simple but effective model adaptation mechanism for intra-frames. Experimental results demonstrate that, compared with JVT-W042, the proposed algorithm achieves higher precise bit estimation, provides more robust buffer control, and improves coding quality.
暂无评论