The problem of the reconstructed of different scene depth was analyzed in single-step holographic stereogram printing based on effective perspective images’ segmentation and mosaicking (EPISM). The reconstructed quality of short scene depth is bad. the causes of flipping effect in holographic stereogram are studied in detail, and the influence of flipping effect on image quality is alleviated by reducing the size of holographic element (Hogel). The curvature distortion of holographic stereogram is analyzed. The effect of curvature distortion on the reconstructed quality of holographic stereogram is verified by changing the distance of object protruding sampling plane. The theoretical analysis was verified experimentally with different scene depth. The reconstructed image of high quality and short scene depth was obtained, and the practicability of EPISM was improved.
Producing of conventional optical reflection hologram can be classified into one-step method and two-step method. In one-step method, only the diverging light of the object could be recorded, and the reconstructed scene is a virtual one behind the recording medium. In two-step method, the diverging light or the converging light could be recorded alternatively. However, the process is complicated considering double exposures. We propose a novel method of one-step reflection hologram. The object is first imaged by a 4f optical system, then the interference fringes are recorded by single exposure. The reconstructed image can be either a virtual image behind the recording medium, or a real image in front of the recording medium. The ideal imaging properties of 4f optical system have been demonstrated theoretically and the proposed method has been verified experimentally.
A spatial frequency index method is proposed to cull the occlusion in computer generated hologram. The object points with the same spatial frequency are put into a set, and only the point closest to the hologram is contributed to the hologram because of their mutual occlusion. The phases of corresponded spatial frequency are precomputed and stored in a table. The phases on the hologram are obtained from the table according to the spatial frequency of object point. Experiments are performed and the results demonstrate that the proposed method can cull the hidden surfaces of 3-D scene correctly. The occlusion effect can be well reproduced along with the speeding up of the calculation.