School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang, Singapore.
IEEE Trans Image Process. 2011 Aug;20(8):2221-8. doi: 10.1109/TIP.2011.2118218. Epub 2011 Feb 22.
Currently, 3-D Video targets at the application of disparity-adjustable stereoscopic video, where view synthesis based on depth-image-based rendering (DIBR) is employed to generate virtual views. Distortions in depth information may introduce geometry changes or occlusion variations in the synthesized views. In practice, depth information is stored in 8-bit grayscale format, whereas the disparity range for a visually comfortable stereo pair is usually much less than 256 levels. Thus, several depth levels may correspond to the same integer (or sub-pixel) disparity value in the DIBR-based view synthesis such that some depth distortions may not result in geometry changes in the synthesized view. From this observation, we develop a depth no-synthesis-error (D-NOSE) model to examine the allowable depth distortions in rendering a virtual view without introducing any geometry changes. We further show that the depth distortions prescribed by the proposed D-NOSE profile also do not compromise the occlusion order in view synthesis. Therefore, a virtual view can be synthesized losslessly if depth distortions follow the D-NOSE specified thresholds. Our simulations validate the proposed D-NOSE model in lossless view synthesis and demonstrate the gain with the model in depth coding.
目前，3D 视频主要针对可调节视差的立体视频应用，其中基于深度图像渲染（DIBR）的视图合成用于生成虚拟视图。深度信息的失真可能会导致合成视图中的几何形状变化或遮挡变化。在实际中，深度信息以 8 位灰度格式存储，而对于视觉舒适的立体对，视差范围通常远小于 256 个级别。因此，在基于 DIBR 的视图合成中，几个深度级别可能对应于相同的整数（或子像素）视差值，使得一些深度失真不会导致合成视图中的几何形状变化。基于此观察，我们开发了一种深度无合成误差（D-NOSE）模型，以检查在不引入任何几何形状变化的情况下渲染虚拟视图时允许的深度失真。我们进一步表明，所提出的 D-NOSE 配置文件规定的深度失真也不会影响视图合成中的遮挡顺序。因此，如果深度失真符合 D-NOSE 指定的阈值，则可以无损地合成虚拟视图。我们的模拟验证了无损视图合成中所提出的 D-NOSE 模型，并展示了该模型在深度编码中的优势。
