三维场景相息图快速生成研究

Research on Fast Kinoform Generation for Three-dimension Scene

相息图以其衍射效率高,无共轭像等优点而被广泛应用于全息三维动态显示中,然而相息图计算量大,生成速度慢而影响了它的实时动态显示;鉴于此,提出了一种三维场景相息图快速生成方法;采用OpenGL进行物点离散采样,逐点计算的优化查表算法进行相息图计算,将相位因子拆成水平方向和竖直方向因子的乘积,离线制作的查找表只需存储水平方向和竖直方向因子,从而使存入GPU纹理内存的查找表空间大大减少,并利用CUDA架构合理设计并行计算方案,使相息图的运算速度进一步加速;实验表明:采用此方法能正确生成所需的相息图,且计算速度比基于CPU的计算方法提高了40倍左右。

Kinoform, with the advantage of high efficient diffraction and non-conjugate image and so on, is widely used in three-dimension dynamic display of holography, however, the kinoform, with large calculation and slow generation speed, affects its real-time dynamic display. According to this, a kind of fast kinoform generation method for three-dimension scene is proposed. By using OpenGL to conduct discrete object point sample collection, by performing kinoform calculation through optimized look-up table algorithm of pointwise calculation, phase factor is decomposed into the product of horizontal direction and vertical direction, offline-made search table only needs to store the factors of horizontal direction and vertical direction, so that the space of search table stored in CPU texture memory is largely reduced, CUDA framework is rationally used to design and calculate the scheme to further speed up the calculation rate of the kinoform. The experiment shows that this method can correctly generate the demanded kinoform and can make the calculation speed increase 40 times or so more than the calculation method based on CPU.