Rate Distortion Optimization using SSIM for 3D Video Coding

Coding efficiency can be enhanced through rate-distortion optimization (RDO) that provides a trade-off between bit-rate and distortion. In this paper, we have proposed Structural SIMilarity (SSIM) based RDO for 3D video coding improvement. SSIM index is a quality metric that gives better approximation to visual quality. Most of the existing literature on 3D video coding employs sum-of-squared error (SSE) as a measure of distortion, which does not always correlate to visual quality. In order to overcome this gap, SSIM-based RDO is implemented in this paper. Lagrange multiplier is modified to obtain optimum rate along with a reduction in distortion which improves the perceptual quality of the video. The entropy of macroblock (MB) is also considered in the scaling of Lagrange multiplier to increase RDO performance. The proposed algorithm is implemented in 3DV-ATM reference software. Experimental results show an improvement in the perceptual quality of the synthesized sequences with bitrate reduction of 6 - 15%.