Research On Polygon-based Method Of Computer-generated Hologram Algorithm And Imaging Quality

Information digitization is the inevitable trend of current era,the application of digital three-dimensional display in culture,medical,military and other important fields play a very important role;where holographic three-dimensional display technology has the ability to truly reconstruct the depth of light wave information.Although traditional holography using photochemical recording media can achieve true color,high resolution and large field of view reconstruction,but it still does not have the flexibility and anti-interference corresponding to the digital trend.In contrast,computer-generated holography has ability to simultaneously reconstruct the light field of real and virtual objects,which ensures its flexibility;and the digital computation of the light field ensures the anti-interference of the data;thus making the digitization of holography possible.However,the digitalization of holography inevitably leads to a sharp increase in the amount of data,how to use less computation to reconstruct the light field distribution of the corresponding object and ensure the reconstruction quality of the light field has become a key issue in the realization of holographic digital 3D display.The computer-generated holographic polygon-based method is the most promising computer-generated algorithm because it uses fewer geometric primitives to describe the 3D scene shape,and can combine with light modeling,texture mapping and other computer graphics techniques to effectively improve the quality of holographic reconstruction.Based on this,we first use the sampling theorem to derive the expressions for the sampling parameters of the holographic plane,and determine the minimum number of samples and the minimum non-under-sampling distance;to ensure that the final computational results will not be impaired by under-sampling.The mathematical expressions of the spectrum of the light field distribution in any non-parallel plane are also derived using the frequency domain properties of the Dirac function,which provides a theoretical basis for the calculation of the light field in any 3D scene.Based on this,the problem of computational inefficiency in the algorithm of texture mapping for computing holographic polygon-based algorithm to improve the reconstruction quality is analyzed;and the FFT based algorithm based on linear mapping and the fully analytical texture rendering algorithm using parallelogram approximation are targeted,both of which can reduce the computational effort by 40% and 50%while maintaining the reconstruction quality,and the objective evaluation indexes such as SSIM proved their feasibility.The above work achieves the reduction of the corresponding computation while maintaining the reconstruction quality of the computer-generated hologram light field,and lays the foundation for the popularization of holographic digital 3D display in the future.