Study On The Fast Algorithm Of Computer-Generate Hologram

With the rapid development of display technique, the traditional two-dimensional display technology has been unable to meet the requirements of people and three-dimensional display technology has gradually become a new research topic. As a true3D display technology, holographic3D display has the advantages of viewing with the naked eye and providing wide color gamut and full depth cues. Computer-generated hologram is a new holographic imaging technique, which simulates the physical process of holographic record by means of using a computer. Comparing to the traditional optical holography and digital holography, it has the advantages of low requirement on environment, flexible and repeatability. However, there still exists some problems to impede the further development of CGH, it is necessary to develop some new algorithms that can greatly reduce the computation time.In order to improve the computational efficiency of computer generated hologram(CGH), a novel algorithm was proposed to obtain multiple-type reconstruction images of CGH based on spectrum diffraction theory. The reconstruction images can be rotated, sheared and inversed by just transforming the coordinates of the Fourier spectrum so that the calculation amount is reduced a lot.For the calculation of triangle mesh object, the Fourier spectrum information of the triangle mesh is expressed as an analytic function by using affine transform theory in this paper. It can solve the problem of doing a Fourier transform operation on each triangle mesh and reduce the amount of computation and improves the computational efficiency.Finally, several methods of calculating3D objects are brief discussed. First, the disadvantages and problems of point algorithm are analyzed. Then, how to calculate the distribution on the hologram plane of a triangle in space is discussed. Last,the paper try to bring the conformal geometry theory in the calculation of3D holography and the feasibility of the algorithm is analyzed from a theoretical point.All the algorithms above are the research of fast CGH algorithms; they can reduce the amount of computation and improve the computational efficiency. They have an impact on the application and development of CGH.