The Theoretical And Technical Research Of Produce Hologram Of Real-Existing Objects By Computer-Generated Holography

Holography is a significant 3D display technique for its true 3D display ability. Although the theory of holography is almost perfect, the practical holographic display technique is not even close to what we expect. Study of practical holography has realistic meaning.To produce hologram of real-existing objects such as human beings by optical holography is difficult for its strict requirement such as coherence and stability. The significance of CGH-based 3D display is that it can avoid laser and extremely strict optical setup. What's more, we can produce hologram of real-existing objects and virtual objects by CGH. Therefore, CGH-based 3D display technique has obvious simplicity and flexibility.Color holography is in site for its color 3D display ability. We have chosen color portrait as research objective based on two reasons. Firstly, color 3D display of portrait is more significant than display of other color objectives. Secondly, the color change of portrait can cause strong visual sensitivity, it will help us to judge the validity of color matching and establish the foundation for making high-quality color hologram.There are mainly four parts in this paper.Firstly, we have summarized of 3D display development. We review the history and current situation of 3D display research detailedly, and analyze the influence of optical holography, computer-generated holography (CGH) and digital holography on 3D display and its developmental trend. In addition, we illustrate in detail the basic ideas and method of this paper. Secondly, we have studied the algorithms of color CGH. We have analyzed in detail the sampling problem of computer-generated Fresnel holograms (CGFH). In addition, we have studied the algorithm of computer-generated rainbow holograms (CGRH). It mainly contains interrelationships between monochrome hologram and color hologram, reproduction of color hologram and elimination of color crosstalk.Thirdly, we have studied color matching problem of color CGH. We have researched the color transfer process in detail. In addition, we rounded analysis the color matching problem based on the calculated wavelength and spectrum of reconstructed image. The color display ability of CGFH and CGRH are illustrated.Fourthly, technique for color CGH of real-existing objects is illustrated. It mainly contains three parts:firstly, we use color 3D scanner to obtain the color 3D data of real-existing objects. Secondly, we calculate the object light distribution based on the propagation principle of light wave. The calculate parameters are determined based on algorithm of combined CGH and optical holography. We obtain the CGFH by simulating the principle of holographic interference. Thirdly, we output the CGFH by a self-made CGH microfilming system on a holographic plate, and the color hologram of real-existing object is obtained by combing CGH and optical holography.In this paper, based on the algorithms and color matching problem of color CGH, we propose a practical method for color holographic display of real-existing objects. We demonstrate the viability of the proposed method theoretically and turn the holographic display of real-existing objects true by CGH, which establishes the foundation of practical use of CGH display technique.