Research On Fast Generation Algorithm Of Calculating Hologram Based On Depth Of Focus

The holographic three-dimensional display uses computer coding technology to encode three-dimensional object information,and then loads the corresponding display device to display three-dimensional object information.As a true three-dimensional display technology,it has been widely used in recent years.In holographic three-dimensional display application research,how to quickly generate high-quality computational holograms is one of the key issues,and it is also one of the factors that currently limit the real-time display of holographic three-dimensional video.At present,the method of segmenting and sampling a three-dimensional object in a holographic calculation process mainly includes a point source segmentation method and a face element segmentation method.Therefore,this paper studies the two-dimensional object segmentation sampling method corresponding to the fast generation algorithm of the computational hologram.Based on the depth of focus analysis of the holographic imaging system,the fast generation algorithm of the computed hologram corresponding to point source segmentation and face element segmentation of the three-dimensional object is improved,and good results are obtained.The main research work is summarized as follows:1.The scalar diffraction theory is the basis for obtaining the optical wave field of matter.Therefore,the basic theory of scalar diffraction and the numerical solution method of light diffraction are analyzed.On this basis,the phase holographic coding method used for the related theory of computational holography and holographic display is analyzed.2.Analyze the impulse response characteristics of the spatial light modulator(LCOS)imaging system,and obtain the energy distribution range of the LCOS reconstruction light field and the relationship between the reconstruction ideal image and the actual defocus image.Based on this,the fast generation algorithm of point source model computational hologram based on LCOS is studied,and a fast computation method based on the WRP projection hologram of point source 3D object in the depth of focus range is proposed,and the fast projection of 3D object layered projection with long depth of field is fast.The calculation method is compared with the imaging quality and calculation speed of the traditional WRP method.Through actual simulation calculations and optical-optical representations,it can be shown that the above method can quickly calculate the point cloud-generated three-dimensional object hologram and the quality of the reproduced three-dimensional image is high.3.Study the fast generation algorithm of computational hologram using the model of triangular facet segmentation object,and correct the core theory of facet method: Based on the affine transformation theory,calculate and calculate in detail the spectrum of the triangle from 2D plane primitives to the spectrum of an arbitrary triangle.,and thus transition to the calculation method of any triangle spectrum in three-dimensional space,correcting the integral transformation and the complex form of the primitive triangle solution and the solution of the Jacobian determinant in previous work,eliminating the problem of loss of the triangular spectrum during the solution,Simplify calculations and increase the speed of hologram generation.4.Based on the point source 3D object projection algorithm in the in-focus depth range,a projection method for the area depth within the computational hologram depth range is proposed.The affine transformation theory is used to establish the spatial relationship between the arbitrary space triangle and the primitive triangle,and the detailed derivation from the primitive triangle to arbitrary The method of calculating the triangular projection transformation improves the calculation speed of the computational surface element method,confirms the positive determination of the bin projection method through simulation calculation and photoelectric reconstruction,and discusses its acceleration characteristics and compares it with the affine analytic surface element method.