全景视频双环带映射算法

Double ring mapping projection for panoramic video

针对全景视频映射过程中局部区域变形过大、冗余数据量极高的问题,提出了一种双环带映射算法(DRP)。首先,根据球面视频的几何特点,结合人眼视度(HVS)这一视觉特性,用两个相互正交的环形区域,将球面视频分割成14个大小相近的区域;然后根据空域采样定理,采用兰索斯插值法,将这14个区域对应的球面视频内容映射为14个大小相等的矩形视频;最后,根据最新视频编码标准的特点,重新排列这14个矩形视频,得到符合编码器标准的紧凑的全景视频。实验结果表明,与经纬图映射算法(ERP)、八面体映射算法(OHP)、二十面体映射算法(ISP)相比,DRP算法在视频压缩性能方面有良好的表现;其中同最流行的ERP算法相比,码率平均降低8.61%,明显提升了视频编码效率。

To solve the problem that some area deforms too large and large volume of redundant data in the process of panoramic video mapping, a Double-Ring mapping Projection （DRP） algorithm was proposed. Firstly, according to the geometric characteristics of spherical video and the visual characteristics of Human Visual System （HVS）, the spherical video was divided into 14 equal-sized regions by two mutually orthogonal ring areas regions. Then, according to the space domain sampling theorem, the 14 regions corresponding to the spherical video content were mapped to 14 rectangular videos with the same size by Lanczos interpolation method. Finally, according to the characteristics of the latest video coding standard, the 14 rectangular videos were rearranged to get a compact panoramic video in keeping with coding standards. The experimental results show that the DRP algorithm achieve a higher compression efficiency compared with the EquiRectangular mapping Projection （ERP） algorithm, OctaHedral mapping Projection （OHP） algorithm and IcoSahedral mapping Projection （ISP） algorithm. Specifically, compared with the most popular ERP algorithm, the proposed method reduces the bit rate by 8.61% which obviously improves the coding efficiency.