Early DIRECT Mode Decision for MVC Using MB Mode Homogeneity and RD Cost Correlation

Multi-view video coding (MVC) adopts variable size mode decision to achieve high coding efficiency. However, its high computational complexity is a bottleneck of enabling MVC into practical real-time applications. In this paper, an early termination strategy is proposed for DIRECT mode decision of MVC by exploiting mode homogeneity and rate distortion (RD) cost correlation. By comparing the RD cost between DIRECT mode and Inter$16\times 16$ mode, an adaptive threshold is defined based on the MB's mode homogeneity and RD cost so as to early terminate the remaining inter and intra modes. Experimental results show that compared with the original JMVC model, the proposed approach can reduce the total encoding time from 65.08% to 91.45% (80.43% on average). Meanwhile, the Bjontegaard delta peak signal-to-noise ratio only decreases 0.031 dB and Bjontegaard delta bit rate increases 0.97% on average, which is a negligible loss of coding efficiency and superior to the performance of state-of-the-art methods.