Hardware and coding efficiency assessment of 3D-HEVC DIS tool using alternative similarity criteria

3D-HEVC is the state-of-the-art standard to compress three-dimensional videos. One of the 3D-HEVC novel tools is the DIS tool, which is used to efficiently compress smooth and homogeneous areas of depth maps by using four different prediction modes. The decision of which DIS mode will be used is done through the SVDC similarity criterion in the DIS original definition. This article proposes the substitution of the complex SVDC criterion for simpler and more hardware friendly criteria as SATD, SSE, and SAD. These alternative criteria were evaluated in terms of encoding efficiency and hardware impacts in comparison with the SVDC. Dedicated DIS hardware were designed using each one of each criterion and these designs were described in VHDL and synthesized for TSMC 40 nm. The best results were found with SAD criteria, with losses of only 0.2% in coding efficiency and with expressive gains of more than 50 times in power and more than 35 times in area, when compared with SVDC. The reached results showed that the use of a simpler similarity criterion is an important alternative to be used in DIS tool, mainly if an efficient hardware design is required.