基于频域滤波的计算机制真彩色彩虹全息图模拟再现

Reconstruction of Computer Generated True Color Rainbow Hologram by Filtering in Frequency Domain

提出了一种计算机制真彩色彩虹全息图模拟再现方法。根据衍射及几何光学的原理,分析了彩色彩虹全息图再现时空间观察窗口与频谱面窗口的对应关系。在计算机中构造照明光(红、绿、蓝三色)的分布,并分别与全息图相乘,采用傅里叶变换对上述结果进行频谱分析,并通过频域滤波获取与特定观察窗口位置对应的频谱信息;然后进行逆傅里叶变换得到全息面上的再现像。将逆傅里叶变换结果衍射一段距离,可得到对应于特定观察窗口、位于不同位置处的再现像。通过计算机模拟得到了与光学再现一致的结果,表明了该方法的可行性。为快速、经济地验证计算机制真彩色彩虹全息图的正确性提供了一种途径。

A method to reconstruct computer generated true color rainbow hologram is presented. Based on the principle of diffraction and geometric optics, the relationship between the observing window in spatial domain and its corresponding window in spatial frequency domain is analyzed. The illumination beams （red, green and blue light） are constructed and multiplied by rainbow hologram respectively. The multiplied results are analyzed in spatial frequency domain with Fourier transform. The spectral information corresponding to a specific perspective window is extracted by filtering in spatial frequency domain. And then the inverse Fourier transform is introduced to obtain the reconstructed image in the hologram plane. The reconstructed images in different positions are obtained from the object wave diffracting a given distance. The experimental results prove the validity of the proposed method. It opens up a new way to evaluate the correctness of computer generated true color rainbow hologram fast and economically.