多视点视频加深度(MVD,multi-view video plus depth)的编码格式包含多个纹理视频序列及其对应的深度图,深度图与对应的纹理视频具有相似的边缘信息。传统的编码模式不考虑两者的联系,单独编码导致复杂度高、编码时间过长。因此,合理利用深度图与纹理图的相似性进行编码,可以有效降低编码复杂度,同时应该确保编码质量不受影响。本文利用深度图的这一特点辅助纹理视频的编码,提出一种帧间快速模式选择算法,充分利用深度图与纹理图之间的相似性,建立一种联合复杂度模型,根据模型得到每个宏块的复杂度。对于复杂度低的宏块,在计算率失真代价之前跳过编码中一些不必要的模式,从而降低编码复杂度。实验表明,本文提出的快速模式选择算法,在保证率失真性能基本不变的情况下,能减少60.57%的编码复杂度,并最高能减少80.64%的编码时间。
Multi-view video plus depth format includes several texture videos and corresponding depth maps. Depth maps play an important role in depth image based rendering (DIBR) and have similar edges with texture videos. Conventional coding methods have high complexity and long coding time because of ignoring the similarity between the depth and texture images. At the same time, it should be ensured that the quality of coding can not be declined. This paper proposes a fast mode decision algorithm for inter mode decision utilizing this characteristic of depth maps. By establishing a model which is named as joint mode complexity, each macro-block will have its own complexity. If the complexity is smaller than a cer- tain value, this macro-block can adopt fast mode decision by skipping some unnecessary modes. The pro- posed method determines to skip some unnecessary modes in the macro-blocks which have low complexi- ty before calculating rate-distortion cost in order to reduce the coding complexity. Experimental results demonstrate that the proposed method reduces 60. 57% computational complexity of encoder with al- most the same R-D performance. The time of coding is declined to a large degree along with the reducing of computational complexity.