Irregular and optimized representations for image based rendering

基于图像的绘制是计算机图形学中一个很有前途的创新领域。在基于图像的渲染中，从输入的图像集或视频序列开始。然后对这些数据进行某种程度的处理，以获得中间表示。这个中间表示法然后被用在交互式计算机图形设置中。这些交互式用途包括但不限于：从输入序列中不可用的新颖视角查看场景，使用输入序列中不可用的虚拟灯光重新照亮场景，以及几何操纵构成场景的对象。这种功能极大地扩大了数字照片的用途，并为交互式计算机图形学的使用引入了丰富的内容来源。对于基于图像的渲染，我们计划关注Lumigraph表示，它是场景中光线沿着传播的采样表示。特别地，静态场景的视觉信息由五维辐射函数表示。该函数描述每个3D空间位置（x; y; z）处每个2D方向的光的强度和颜色。如果我们只考虑离开凸船体有界物体（或等效地进入有界空间的空区域）的光的子集，则辐射沿着任何射线保持恒定1的事实允许我们将辐射函数的感兴趣域从5维减少到4维。

ABSTRACT0203932Gortler, StevenHarvard UniversityImage based rendering is a promising area of innovation in computer graphics. In image based rendering,one starts with an input set of images or a video sequence. One then applies some degree of processingto this data to obtain an intermediate representation. This intermediate representation is then used in aninteractive computer graphics setting. These interactive uses include but are not limited to: viewing thescene from novel points of view that were not available in the input sequence, relighting the scene usingvirtual lights that were not available in the input sequence, and geometrically manipulating the objects thatmake up the scene. This functionality greatly enlarges the uses of digital photographs, and introduces a richsource of content for use in interactive computer graphics.For image based rendering, we plan to focus on lumigraph representations, which are a sampled repre-sentation of the light that travels along the rays in the scene. In particular, the visual information of a static scene is represented by the five dimensional radiance function. This function describes the intensity and color of light for every 2D direction at every 3D spatial position (x; y; z). If we consider only thesubset of light leaving the convex hull bounded object (or equivalently entering a bounded empty region ofspace), the fact that radiance along any ray remains constant 1 allows us to reduce the domain of interest ofthe radiance function from five to four dimensions.