基于反向映射的元素图像生成算法

Elemental Image Generation Algorithm Based on Reverse Mapping

传统方法是建立从光场到显示面的映射计算生成元素图像,但会存在很多冗余映射。针对这一问题,提出沿光路逆向迭代的算法,建立从元素图像显示面到重建光场的单射,使元素图像中的每个像素只对应唯一的光场像素,这可以提高像素的匹配精度,消除深度阶跃处的空洞。所提算法的核心是以元素图像显示面每一点为始点,经过透镜的光心作射线,通过迭代搜索求出射线与光场曲面距离观察者最近的交点,并作为元素图像的匹配点。所提算法的时间复杂度主要受控于元素图像阵列的像素总和,元素图像的计算生成速率是现有算法的8倍以上,图像中的像素总数越大,所提算法的速率优势越明显,且实验结果验证理论推导的正确性。

The traditional method is to establish a mapping calculation from the light field to the display surface to generate elemental images,but there will be a lot of redundancy.To solve this problem,an iterative algorithm along a mapped light path is proposed so that a single shot from an elemental image display surface to a reconstructed light field can be established.Each pixel in an elemental image only corresponds to a unique light-field pixel,which can improve the pixel matching accuracy and eliminate a depth void at a step.The core of the proposed algorithm is based on each point on a display surface of an elemental image as the starting point,passing through the optical center of a lens as a ray through an iterative search to find the intersection of the ray and light field surface closest to an observer.Such an intersection is used as the matching point of the elemental image.The time complexity of the proposed algorithm is mainly controlled by the sum of pixels of an elemental image array.Calculation and generation rates of elemental images using the proposed algorithm are usually more than eight times those of the existing algorithm.An advantage of the proposed algorithm is that the total number of pixels in the image is directly proportional to the speed of the algorithm.The experimental results verify the correctness of the theoretical statements emphasized in this study.