Abstract: Aiming at the problem of holes, resampling and overlapping generated in the Double-sided Depth-Image Based Rendering technology, in order to improve the quality of virtual viewpoint, an improved forward and reverse wraping DIBR technology is proposed. The technology has four contributions mainly. A depth difference estimation algorithm is proposed firstly. Secondly, the improved OPFD algorithm based on Z-buffer is used in 3D-warping, and the problem of resampling and overlapping is resolved effectively. The improved background-based holes filling algorithm is used for depth virtual image to eliminate holes thirdly. Forthly the forward and reverse wraping process is improved, through judging the consistency of background of blocked information of projected image and auxiliary color reference image. The different holes filling algorithms are selected to fill the holes in the color virtual image so as to achieve a better holes filling effect. Experimental results indicate that the improved technology significantly reduces the complexity of the algorithm, at the same time, enhancing the quality of picture, PSNR and SSIM compared with traditional FR-DIBR technology.

Key words: depth-image based rendering, 3D-warping, Double-sided Depth-Image Based Rendering（DIBR）, Forward and Reverse warping-Depth-Image Based Rendering（FR-DIBR）, resampling, hole, virtual view synthesis

摘要： 针对基于双向深度图像绘制技术（Double-sided Depth-Image Based Rendering，Double-sided DIBR）中产生的空洞、重采样、重叠问题，为提高虚拟图像的合成质量，提出一种改进的正反向映射技术。该技术主要有四点贡献。（1）提出一种深度差值估计法。（2）在3D-warping过程中使用改进的基于Z-buffer的OPFD算法，有效解决重采样和重叠问题。（3）对深度虚拟图像运用改进的基于背景空洞填补算法消除空洞。（4）改进反向映射过程，通过判断投影后的图像和辅助彩色参考图像被遮挡信息背景的一致性，选择不同的空洞填补算法填补彩色虚拟图像中的空洞，从而达到更好的填补效果。实验结果表明，改进技术在降低算法复杂度的同时，主观图像质量与客观峰值信噪比（Peak Signal to Noise Ratio，PSNR）以及结构相似（Structural SIMilarity，SSIM）都有所提高。

关键词: 基于深度图像的绘制, 三维图像映射, 双向深度图像绘制技术, 正反映射DIBR, 重采样, 空洞, 虚拟视点合成