In this paper, a uniform multiple wavefront recording planes (UM-WRPs) method for enhancing the image quality of the RGB-depth (RGB-D) image hologram is proposed. The conventional multiple wavefront recording planes (M-WRPs) based full-color computer-generated hologram (CGH) have color uniformity problem caused by intensity distribution. In order to solve the problem, the proposed method generates depth-related wavefront recording planes (WRPs) to enhance the color uniformity and accelerate hologram generation using a fixed active area. Compared with conventional MWRPs methods, the quality of reconstructed images of this method is improved significantly. The image improvement of the proposed method is confirmed by numerical reconstruction
In this paper, we propose a robust 3D image encryption scheme based on computer-generated hologram (CGH) in fractional Fourier domain. The layer-based Fresnel transform is utilized to generate one phase-only CGH, which is then decomposed into two phase-only masks (POMs) by pixel superimposed method. Encryption was realized by using the created POMs in two cascaded fractional Fourier transform domains while two decryption keys are produced in the encryption process. The cryptosystem is asymmetric and high resistance against to the various potential attacks, including chosen-plaintext attack (CPA). The proposal is supported with computer simulation results. Simulation results and security analysis verify the feasibility and effectiveness of the proposed encryption scheme.
In this paper, we focused on the improvement of reconstructed image quality of the mobile three-dimensional display using the computer-generated integral imaging. The three-dimensional scanning method is applied instead of capturing the depth image in the acquisition step, and much more accurate three-dimensional view information (parallax and depth) can be acquired compared with the previous mobile three-dimensional integral imaging display, and the proposed system can reconstruct clearer three-dimensional visualizations of real-world objects. Here, the three-dimensional scanner acquires the three-dimensional parallax and depth information of the real-world object by the user. Then, the entire acquired data is organized and the three-dimensional the virtual model is generated based on the acquired data, and the EIA is generated from the virtual three-dimensional model. Additionally, in order to enhance the resolution of the elemental image array, an intermediate-view elemental image generation method is applied. Here, five intermediateview elemental images are generated between each four-original neighboring elemental image according to the pixel information, at least, the resolution of the generated elemental image array is enhanced almost four times than original. When the three-dimensional visualizations of real objects are reconstructed from the elemental image array with enhanced resolution, the quality can be improved quite comparing with the previous mobile three-dimensional imaging system. The proposed method is verified by the real experiment.
We proposed a fast scheme for computer-generated holography (CGH) to mix 3D scenes. The objects in the proposed include the real and virtual objects. Make a point cloud model of real object, and then converted to a triangular mesh model. And mix the triangular mesh model with virtual 3D object mesh models. Using the angular spectrum method to generated hologram, and it is convenient to accelerating with GPU.
A depth camera has been used to capture the depth data and color data for real-world objects. As an integral imaging display system is broadly used, the elemental image array for the captured data needs to be generated and displayed on liquid crystal display. We proposed a real-time integral imaging display system using image processing to simplify the optical arrangement and graphics processing unit parallel processing to reduce the time for computation. The proposed system provides elemental images generated at a rate of more than 30 fps with a resolution of 1204×1204 pixels , where the size of each display panel pixel was 0.1245 mm, and an array of 30×30 lenses , where each lens was 5×5 mm .