Keita Tahahashi
IEEE Transactions on Image Processing, Vol. 21, Issue 2, pp. 718--732, 2012
Abstract: A problem of view interpolation from a pair of rectified stereo images with inaccurate depth information is addressed. Errors in geometric information greatly affect the quality of the resulting images since inaccurate geometry causes mis-correspondences between the input images. A new theory for quantitatively analyzing the effect of depth errors and providing a principled optimization scheme based on the mean squared error metric is proposed. The theory clarifies that if the probabilistic distribution of the depth errors is given, an optimized view interpolation scheme that outperforms conventional linear interpolation can be derived. It also reveals that under specific conditions, linear interpolation is acceptable as an approximation of the optimized interpolation scheme. Furthermore, band limitation combined with linear interpolation is also analyzed, leading to an optimal cut-off frequency, which achieves better results than the anti-alias scheme proposed in previous studies. Experimental results using real scenes are also presented to confirm this theory.
Keita Takahashi
Abstract: Depth inaccuracy greatly affects the quality of free-viewpoint image synthesis. A theoretical framework for a simplified view interpolation setup to quantitatively analyze the effect of depth inaccuracy and provide a principled optimization scheme based on the mean squared error metric is proposed. The theory clarifies that if the probabilistic distribution of disparity errors is available, optimal view interpolation that outperforms conventional linear interpolation can be achieved. It is also revealed that under specific conditions, the optimal interpolation con- verges to linear interpolation. Furthermore, appropriate band-limitation combined with linear interpolation is also discussed, leading to an easy algorithm that achieves near-optimal quality. Experimental results using real scenes are also presented to confirm this theory.
Keita Takahashi, Takeshi Naemura
Abstract: This paper discusses a view interpolation problem where a new view would be synthesized at the midst of two parallel views. We first introduce a new theoretical model that describes the relation between accuracy of disparities and the quality of the interpolated view. Then, we derive the optimal prefilter that minimizes the power of errors on the interpolated view. Our approach is inspired by the rate-distortion theory for video coding, and can be also regarded as an attempt to reconsider the plenoptic sampling theory. Finally, we present numerical simulations and experimental results to validate our theory.