基于空间频率分析的计算全息信息压缩研究

Information Compression of Computer-generated Hologram Based on spatial frequency analysis

针对计算全息图信息量大,对电子设备的内存、分辨率要求高的问题,研究了计算全息图的信息量与空间频率的关系,通过降低空间频率,压缩计算全息的信息量。基于光学全息理论,用最高空间频率分析法对全息图的空间频率进行研究,确定了计算全息的最大空间频率,给出了频谱分布;在此基础上,利用计算机去除计算全息的冗余频谱,消除了零级衍射像,降低了空间频率,压缩了信息量;设置相关参数,使计算全息各频谱刚好相互分离不重叠。通过实验进行验证,给出了理论推导与实验结果。

Computer generated hologram （CGH） in general have large amount of information, which need elec- tronic equipments such as computer to have large memory and high resolution to match it, and this make it difficult for CGH to be generalized. In order to solve this problem, the relationship of spatial frequency of CGH to amount of information of CGH is studied, and the method to compress the amount of information of CGH through reducing the spatial frequency of CGH is introduced. Firstly, based on the theory of optical holography, spatial frequency of CGH is analyzed, the maximum spatial frequency of CGH is calculated and the spatial spectral distribution of CGH is obtained. Then, taking advantage of the flexibility of computer generated holography, the redundant frequency spectrum of CGH that results in zero-order diffraction is eliminated, thus the spatial frequency as well as the amount of information of CGH is reduced greatly. In the same time, the parameters of CGH are set accurately to just separate different spectra. An experiment is made to verify the theory, the principle and experiment result are given.