Adaptive Region based Rate Controlat the LCU Level of 3D-HEVC

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3D videos provide viewers strong stereoscopic feeling and telepresence, but it generates a huge amount of data with a hidden issue on data transmission and storage. However, there is few previous work focused on improving the rate control algorithms of 3D videos. Thus, this thesis proposes a rate control algorithm at the LCU level for 3D color video coding. This research is composed of three parts. The first part of this thesis is the weight map design for rate control. Since poor efficiency of rate control often occurs with the mismatch between the actual bitrate and the target bitrate, it easily causes bit starvation especially for regions which needs higher bits for coding. Therefore, this thesis defines a high bitrate cost region as the intra-frame high complexity region, inter-frame variation region, and inter-view variation region. The second part of this thesis is optimal bit allocation. We use recursive Taylor expansion (RTE) to find the optimal bit allocation for each region. In addition, because each frame is encoded from top to bottom and from left to right, the coding units (CU) that are coded later is more prone to bit starvation. In order to achieve better visual quality, the third part of this thesis proposes to adopt the novel concept of retained earnings for rate control. We design a mechanism of retained bits earnings to keep the image quality for the synthesized important regions. In our experiment, the implementation is based on 3D high efficiency video coding (3D-HEVC) software HTM10.0. The results show that our proposed performance is better than HTM10.0 with the R-λ model with 1.24% BDBR decrease, 0.035 dB BDPSNR increase, and 0.56% bitrate error.