Research On Three-dimensional Holography And Computer Generated Hologram’s Encoding And Reproduction Based On MATLAB

In recent years, three-dimensional display technique has been developing rapidly. Holographic display technique becomes the best way of3D display for its capacity of recording the waves’complete information. Compared with traditional optical holography, computer generated hologram (CGH) has less requirements on the environmental conditions. Therefore, producing hologram and realizing3D reproduction by computer generated technique is becoming the future trends.This paper introduced the computer generated technique development history and the current development in holographic display technology at home and abroad. Three kinds of classification methods of CGH, computer generated technique’s basic theory and two encoding methods of CGH--Detour phase encoding and modified off-axis reference beam encoding method were presented. In this paper, the two encoding methods were used to producing Fourier CGH and Fresnel CGH. The two types of CGH and reconstructed images were obtained by MATLAB programming and simulated by computer. The advantages and disadvantages of the encoding methods mentioned above were analyzed. For Fourier CGH, by using Roman detour phase encoding and Modified off-axis reference beam encoding method (Boqi encoding.. Huang encoding、Lee encoding), we reproduced and simulated the reconstructed images. The calculating time of detour phase encoding and modified off-axis reference beam encoding method (Boqi encoding) was compared under the same conditions. The quality (image brightness and signal to noise ratio) of the three kinds of Modified off-axis reference beam encoding method was analyzed. For Fresnel CGH, two kinds of Fresnel diffraction--Convolution algorithm and Fourier transform algorithm were analyzed in this paper. We produced gray image and color image CGH by Boqi encoding method respectively and reproduced them by Fourier transform algorithm. Good reconstructed images were obtained through filtering processing.By presenting the holographic display methods used to calculate the3D objects, this paper focused on the research of object point scattering, holographic tomography and multi-angle projection methods.3D representation feasibility of holographic tomography was confirmed by simulating simple3D object and reproducing its image with MATLAB. For multi-angle projection, assuming the observing point was immovable, parallel transported object in a one-dimensional plane and obtained multiple perspective projection planes. Synthetic hologram was gained by adding hologram of each projection plane and representation image was gained by MATLAB programming.