Model-based Lagrangian multiplier derivation method for depth map coding

Rate-distortion optimisation (RDO) is the key technology that is used to choose the optimal coding parameters in video coding. As the Lagrangian multiplier plays a vital role in RDO, a model-based Lagrangian multiplier derivation method is proposed for depth map coding. This method is based on the analysis of the relationships among the Lagrangian multiplier, the coding distortion, the coding bitrate and the quantisation step. Experimental results demonstrate that the proposed method can achieve an average 3.42% bitrate saving compared with the method in HTM 16.0 reference software, and an average 0.41% bitrate saving compared with a state-of-art method.