Fast Mode Decision Based on Gradient Information in 3D-HEVC

Abstract

The 3D extension of High Efficiency Video Coding (3D-HEVC) introduce Depth Modeling Mode (DMM) and 35 conventional intra modes to enhance the quality of coding, while bringing unacceptable computational complexity during the process of rough mode decision (RMD) and most probable mode (MPM). In this paper, we proposed a fast mode decision algorithm for texture map and depth map coding based on gradient information. Firstly, analyzing the characteristics of predict units (PU) in different intra mode applications that obtain the lowest RD-cost,then extracting the gradient information of PU to classify the PU into three types of gradient blocks and selecting appropriate candidate modes for the PU,thereby avoiding search each mode in coding process and skip the process of RMD and MPM early. Experimental results show that the proposed algorithm can achieve average 30.6% time saving with negligible reduction of coding performance.

A Fast and Efficient 3D-HEVC Method for Complexity Reduction Based on the Correlations of Inter-View, Spatio-Temporal, and Texture-Depth

“…In addition to HTM, the proposed overall method is also compared with state-of-the-art works for an objective comparison. These algorithms include FDML [32], FDTFD [33], FDTC [35], OLCR [37], FMDR [38], FMDG [40], and FMCC [41], which are the fast and efficient algorithms for 3D-HEVC. Note that, the FDTC and OLCR method are designed for texture coding only in 3D-HEVC; the FDML and FDTFD method are designed for depth coding only in 3D-HEVC.…”

“…To evaluate the performance of proposed overall method, the proposed fast scheme is implemented on recent 3D-HEVC encoder (HTM 16.1 [40]). We have tested eight MVD sequences in two resolutions (1024×768 and 1920×1088) recommended by JCT-3V Group from common test condition (CTC) [41].…”

“…In these sequences, the "Shark", "Undo_Dancer", and "GT_Fly" are synthetic video sequences with high precision depth map, the "Kendo", "Balloons", "Newspaper", "Poznan_Hall2", and "Poznan_Street" are natural video sequences with estimated depth map. Test conditions are used as follows: three-view case: center view -left view -right view (in coding order), QP are set as (25,34), (30,39), (35,42) and (40,45), the maximum coding unit is 64×64 pixels, a max partition depth is 4. In this section, we compare the proposed fast method with HTM16.1 and the state-of-the-art fast methods [33], [35], [36], [38], where the compression efficiency is measured by BDBR [42], and " TS " means the entire encoding time saving compared with 3D-HEVC, which is defined as follow, (10) where proposed Time and origional Time denote encoding time of the proposed scheme and original 3D-HEVC for same test video, respectively.…”

“…An efficient CU partition process method is employed in [39] to save coding time for real-time applications. A fast mode decision method is introduced in [40] to save the coding time of 3D-HEVC by using the gradient information. In our previous work [41], a fast MVD coding scheme including fast motion and mode size selection is presented for 3D-HEVC, where about 60.1% complexity reduction is achieved with only 0.57% BD-rate loss.…”

Fast Texture Coding Based on Spatial, Temporal and Inter-View Correlations for 3D Video Coding

“…The fast algorithms to accelerate the coding of 3D-HEVC has been investigated lastingly [11]- [14]. Several mechanisms have been proposed for fast color texture coding.…”