![]() ![]() E-DBS is based on the same pixelwise evaluation strategy of DBS, but the diffraction field of a single pixel is precomputed as a lookup table. In this paper, we proposed an enhanced DBS (E-DBS) method to speed up the hologram computation. However, DBS is a time-consuming algorithm and thus is impractical for the generation of high-definition computer-generated holograms. Therefore, both the quality and diffraction efficiency of the generated binary hologram are better among various algorithms of the binary hologram. DBS performs quality evaluation on every pixel. The direct binary search (DBS) algorithm was originally invented for the synthesis of a binary Fourier hologram, and was applied for the generation of a binary Fresnel hologram recently. Numerical experiments conducted at increasing degree of pincushion distortion proved its insignificant influence on the reconstructed images in all practical cases by using a peak signal-to-noise ratio and the structural similarity as an image quality metrics. #STEREOGRAM HD SIMULATOR#By tracking all steps from acquisition to recording, the simulator allows for analysis of radial distortions caused by the optical elements used at the recording stage. #STEREOGRAM HD FULL#This study presents a simulator which builds a full parallax and full color white light viewable holographic stereogram from the perspective images captured by a virtual recentering camera with its further numerical reconstruction for any viewer location. A holographic stereogram encodes 2D images of a 3D scene that are incoherently captured from multiple perspectives and rearranged before recording. Successful commercialization of holographic printers based on holographic stereograms requires a tool for their numerical replaying and quality assessment before the time-consuming and expensive process of holographic recording. Because the table size is very small, the computing time of SDLUT method can be nearly 80 times faster than that of conventional LUTs in the spatial domain, while the image quality is comparable. In our demonstration, the table size of SDLUT is only 0.44% that of the look-up table (LUT). In the computing of the hogels, the field superposition is conducted in the spectrum domain by using the elemental tables. Because the signal energy always concentrates in a small spectrum region, these regions are cropped as the elemental tables. Subsequently, the fields are Fourier transformed to the spectrum domain. In SDLUT, diffraction fields on the hogel plane of selected reference points in the object space are calculated. Here, we proposed a fast calculation scheme of DA-CGHS by the spectrum-domain look-up table (SDLUT) method. However, its computing cost is extremely high because numerous scenes together with depth information must be calculated. High-definition depth-added computer-generated holographic stereogram (DA-CGHS) is superior in its high quality, easy realization, and auto-shading effect. ![]() Thus, a strategy for efficient intensity accumulation is suggested. Finally, there is an upper-quality limit of the reconstructed image by intensity accumulation. In addition, if the computational efficiency is a concern, the CGH calculated with iterations is not recommended for intensity accumulation display. Using this model, we have confirmed that the randomness induced by random phase is equivalent to that induced by random down-sampling for the generation of binary CGHs. In this paper, we propose an empirical formula of the average noise based on the speckle phenomenon in a laser projector. However, there is no simple method to predict the dependence of the average noise and accumulation number, and we can only know the results after finishing the full computation. Intuitively, the quality of the reconstructed image should be proportional to the number of intensity accumulation. If enough randomness is added to the CGHs, the speckle noise can be mostly averaged out. Thanks to the fast frame rate of the binary spatial light modulator, the speckle can be significantly suppressed by intensity accumulation, i.e., the sequential display of multiple CGHs of the same scene. The image generated by binary computer-generated holograms (CGHs) always suffers from serious speckle noise. ![]()
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