光场相机2.0算法.ppt

Combining depth-based rendering and rendering with blending Calibrating focused plenoptic camera Calibrating focused plenoptic camera Calibrating focused plenoptic camera Calibrating focused plenoptic camera 蓝色，透镜图像，绿色，是传感器图像 Resample the image, rotating and scaling ,lenselet centers fall on pixel centers. 1→2 Calibrating focused plenoptic camera Aligning the lenselet images to an integer pixel grid: The light field is broken into identically sized, overlapping rectangles centered on the lenselet images. k,l→ lenselet, i,j →pixel Calibrating focused plenoptic camera Converting hexagonally sampled data to an orthogonal grid. l. Condat, B. Forster-Heinlein, and D. Van De Ville. H2O: reversible hexagonal-orthogonal grid conversion by 1-D filtering. In Image Processing, 2007, ICIP 2007, IEEE Intl. Conference on, volume 2, pages II-73, IEEE, 2007. 1D scheme interpolating only along k Angle-sensitive pixel 关键：传感器测量强度的不同来获取光场中角度信息 用一对衍射光栅放置在传感器上来获取角度信息。从上面照明，上层的光栅产生周期的衍射图案，下面一个光栅用来选择衍射光线传播到光电探测器的方向。 A wang, P Gill and A Molnar. Applied Optics 48, 5897-5905(2009) P.R. Gill, C Lee, D. G, Lee, A Wang and A Molnar. Optics letters 36,2949-2951(2011) A Wang and A Molnar. IEEE Journal of Solid-State Circuits,1-1(2012) Talbot effect talbot效应是一个近场效应，即要求F大于等于一。在理想情况下，一束平面波通过一个周期性的衍射光栅，由惠更斯原理，我们可以给出经过光栅后光场的分布。考虑Fresnel衍射，得到一个新的近似的光场分布。然后经过傅里叶变换并利用像函数卷积可以发现这个新的光场分布与衍射光栅上的光栅分布只差一个相位。当相位差满足2PI的整数倍的时候就可以得到与衍射光栅上相同的光场分布，这一相位因子只与观察点到光栅的垂直距离有关 Angle-sensitive pixel 要能满足下面两个条件： 探测局部的入射角和入射强度 探测角度的固有周期 可以用8个像素来全面获取局部入射角信息 Angle-sensitive pixel (a)ASP模型 (b1)进入ASP后光线均分 (b2)进入ASP光线的差异反演入射角度 Angle-sensitive pixel w is the opening size of individual pixels. h is the thickness of the top passivation layer. n is the refraction layer index of the passivation layer. W Angle-sensitive pixel The FDTD simulation of the front-side illuminated ASP design with normal incidence(a) and 10 degree incidence(b). The wavelength is chosen to be 550 nm, the center of visible spectrum. Angle-sensit