光子学报, 2014, 43 (5): 0509001, 网络出版: 2014-06-03
三维点云物体频谱获取方法
A Method for Spectrum Extraction of 3D Object with Object Points
全息 计算全息 三维频谱 傅里叶变换 三维点云物体 视图 Holography Computer-generated hologram 3D spectrum Fourier transform 3D object with object points Perspectives
摘要
为了简化三维物体计算全息数据和加快计算时间,提出了一种三维点云物体频谱获取方法.在分析频谱获取方法模型的基础上,由不同视角的投影图像(视图)与对应的平面波因子相乘积分的方法得到了三维点云物体频谱;介绍了视图获取算法,使用Matlab并行计算得到了一个三维‘鸟’的视图序列;根据实际物体频谱分布情况,采用高阶高斯概率分布减少视图获取数量;通过视图序列得到三维物体的频谱,采用傅里叶逆变换得到物空间内一个平面的复振幅分布,将其衍射一段距离,编码为菲涅尔全息,并进行了模拟再现和实验验证.模拟再现和实验结果表明:只需要原总视图的17.75%可以获得高质量的再现效果,验证了频谱获取方法的可行性及视图获取简化模型的正确性.所获取的三维物体频谱可以通过一定方式编码成多种全息进行三维显示,拓宽了该频谱获取方法的应用范围.
Abstract
To simplify the calculation of three-dimensional objects and accelerate the computation time about holographic data, a method for spectrum extraction of 3D object with object points was presented. The spectrum method for model was analyzed and the spectrum could be derived from the integration of a perspective image multiplied by a factor of a specific plane wave. The algorithm for perspectives generation of an object was discussed in detail. The parallel computation with Matlab language was used to reduce the computational burden. And a 3D bird was tested with this method to generated perspectives. Based on the spectrum distribution of real object, a simplified extraction model with high order Gauss probability distribution was proposed which could hugely reduce the number of perspectives needed to form 3D spectrum. The inverse Fourier transform was used to get complex amplitude distribution in a plane of object field and the result was diffracted and added a reference wave in order to code as Fresnel hologram. The numerical reconstruction and experiment indicate that only 17.75% of the total original views can get high-quality reconstructed image and validity of the proposed method. The 3D spectrum can be coded as different kind of holograms for 3D display and it extends the application of 3D spectrum.
简献忠, 周海, 杨鑫, 侯乐鑫, 郭强. 三维点云物体频谱获取方法[J]. 光子学报, 2014, 43(5): 0509001. JIAN Xian-zhong, ZHOU Hai, YANG Xin, HOU Le-xin, GUO Qiang. A Method for Spectrum Extraction of 3D Object with Object Points[J]. ACTA PHOTONICA SINICA, 2014, 43(5): 0509001.