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Computer generated hologram|8 Article(s)
Holographic display based on compressive sensing (Invited Paper)
Mozhou Sha, Juan Liu, Xin Li, and Yongtian Wang
We propose a method to improve the quality of the reconstructed images based on compressive sensing principles. The pseudo-inverse matrix and the total variation minimization algorithms are combined to reduce the sampling number of the computer generated hologram. Numerical simulations are performed and the results indicate that the peak signal to noise ratio is increased and the sampling ratio is decreased at the same time for holographic display. We propose a method to improve the quality of the reconstructed images based on compressive sensing principles. The pseudo-inverse matrix and the total variation minimization algorithms are combined to reduce the sampling number of the computer generated hologram. Numerical simulations are performed and the results indicate that the peak signal to noise ratio is increased and the sampling ratio is decreased at the same time for holographic display.
Chinese Optics Letters
- Publication Date: Jan. 01, 2014
- Vol. 12, Issue 6, 060023 (2014)
Theoretical bounds on Fresnel compressive holography performance (Invited Paper)
Adrian Stern, and Yair Rivenson
During the last years the theory of compressive sensing has found significant utility in the digital holography realm. In this letter we summarize and extend our previous theoretical results which determine the relation between the number of Fresnel samples required on the object illumination type, illumination wavelength, imaging geometry and sensor's size and resolution. During the last years the theory of compressive sensing has found significant utility in the digital holography realm. In this letter we summarize and extend our previous theoretical results which determine the relation between the number of Fresnel samples required on the object illumination type, illumination wavelength, imaging geometry and sensor's size and resolution.
Chinese Optics Letters
- Publication Date: May. 30, 2014
- Vol. 12, Issue 6, 060022 (2014)
Fast calculation of wave front amplitude propagation: a tool to analyze the 3D image on a hologram (Invited Paper)
J. -S., and D. P.
A simple approach to calculate the amplitude component of a wave front propagating in space from a hologram is proposed. It is able to calculate the amplitude distribution on a plane at any distance rapidly using a standard GPU. This is useful for analyzing and reconstructing the 3D image encoded on a hologram. A simple approach to calculate the amplitude component of a wave front propagating in space from a hologram is proposed. It is able to calculate the amplitude distribution on a plane at any distance rapidly using a standard GPU. This is useful for analyzing and reconstructing the 3D image encoded on a hologram.
Chinese Optics Letters
- Publication Date: May. 30, 2014
- Vol. 12, Issue 6, 060021 (2014)
One step hologram calculation for multi-plane objects based on nonuniform sampling (Invited Paper)
Chenliang Chang, Jun Xia, and Wei Lei
The nonuniform sampling method in hologram plane is proposed to reconstruct objects on multi-plane simultaneously. The hologram is nonuniformly sampled by decomposing it into several parts with various sampling rates. The hologram is calculated based on the nonuniform fast Fourier transform (NUFFT) algorithm. In the experiment, we load this nonuniformly sampled hologram on phases-only spatial light modulator (SLM), and by illumination with collimated light objects with different sampling rates are reconstructed at different distant planes simultaneously. Both of the numerically simulation and optical experiments are performed to demonstrate the feasibility of our method. The experiment also shows that our proposed nonuniform sampled hologram for multi-plane objects is calculated by only one step, better than conventional method that needs several steps of calculation proportional to the numbers of object planes. The nonuniform sampling method in hologram plane is proposed to reconstruct objects on multi-plane simultaneously. The hologram is nonuniformly sampled by decomposing it into several parts with various sampling rates. The hologram is calculated based on the nonuniform fast Fourier transform (NUFFT) algorithm. In the experiment, we load this nonuniformly sampled hologram on phases-only spatial light modulator (SLM), and by illumination with collimated light objects with different sampling rates are reconstructed at different distant planes simultaneously. Both of the numerically simulation and optical experiments are performed to demonstrate the feasibility of our method. The experiment also shows that our proposed nonuniform sampled hologram for multi-plane objects is calculated by only one step, better than conventional method that needs several steps of calculation proportional to the numbers of object planes.
Chinese Optics Letters
- Publication Date: May. 20, 2014
- Vol. 12, Issue 6, 060020 (2014)
Bounding box extraction from spherical hologram of elementary object to synthesize hologram of arbitrary three-dimensional scene with occlusion consideration (Invited Paper)
Jae-Hyeung Park, and Hong-Gi Lim
A novel method to extract a bounding box that contains the three-dimensional object from its spherical hologram is proposed. The proposed method uses the windowed Fourier transform to obtain the angular distribution of the quasi-collimated beams at each position in the spherical hologram and estimates the bounding box by accumulating the quasi-collimated beams in the volume inside the spherical hologram. The estimated bounding box is then used to realize occlusion effect between the objects in the synthesis of the three-dimensional scene hologram. A novel method to extract a bounding box that contains the three-dimensional object from its spherical hologram is proposed. The proposed method uses the windowed Fourier transform to obtain the angular distribution of the quasi-collimated beams at each position in the spherical hologram and estimates the bounding box by accumulating the quasi-collimated beams in the volume inside the spherical hologram. The estimated bounding box is then used to realize occlusion effect between the objects in the synthesis of the three-dimensional scene hologram.
Chinese Optics Letters
- Publication Date: May. 28, 2014
- Vol. 12, Issue 6, 060019 (2014)
Computer generated hologram from full-parallax 3D image data captured by scanning vertical camera array (Invited Paper)
Masahiro Yamaguchi, Koki Wakunami, and Mamoru Inaniwa
Full-parallax light-field is captured by a small-scale 3D image scanning system and applied to holographic display. A vertical camera array is scanned horizontally to capture full-parallax imagery, and the vertical views between cameras are interpolated by depth image-based rendering technique. An improved technique for depth estimation reduces the estimation error and high-density light-field is obtained. The captured data is employed for the calculation of computer hologram using ray-sampling plane. This technique enables high-resolution display even in deep 3D scene although a hologram is calculated from ray information, and thus it makes use of the important advantage of holographic 3D display. Full-parallax light-field is captured by a small-scale 3D image scanning system and applied to holographic display. A vertical camera array is scanned horizontally to capture full-parallax imagery, and the vertical views between cameras are interpolated by depth image-based rendering technique. An improved technique for depth estimation reduces the estimation error and high-density light-field is obtained. The captured data is employed for the calculation of computer hologram using ray-sampling plane. This technique enables high-resolution display even in deep 3D scene although a hologram is calculated from ray information, and thus it makes use of the important advantage of holographic 3D display.
Chinese Optics Letters
- Publication Date: May. 30, 2014
- Vol. 12, Issue 6, 060018 (2014)
Data-embedded-error-diffusion hologram (Invited Paper)
P. W., and T.-C. Poon
This paper describes a method for converting a complex Fresnel hologram into a phase-only hologram that can be embedded with large amount of data. Briefly, each row of pixels in the hologram is scanned sequentially in a left-to-right direction. The magnitude of each visited pixel is set to a constant, and its phase is embedded with the data. Subsequently, the error is diffused to the neighborhood pixels. The phase hologram realized with such means, which is referred to as the data-embedded-error-diffusion (DEED) hologram, is capable of preserving high fidelity on the content of the hologram and the embedded data. This paper describes a method for converting a complex Fresnel hologram into a phase-only hologram that can be embedded with large amount of data. Briefly, each row of pixels in the hologram is scanned sequentially in a left-to-right direction. The magnitude of each visited pixel is set to a constant, and its phase is embedded with the data. Subsequently, the error is diffused to the neighborhood pixels. The phase hologram realized with such means, which is referred to as the data-embedded-error-diffusion (DEED) hologram, is capable of preserving high fidelity on the content of the hologram and the embedded data.
Chinese Optics Letters
- Publication Date: May. 28, 2014
- Vol. 12, Issue 6, 060017 (2014)
Acceleration method for computer generated spherical hologram calculation of real objects using graphics processing unit (Invited Paper)
Gang Li, Keehoon Hong, Jiwoon Yeom, Ni Chen, Jae-Hyeung Park, Nam Kim, and Byoungho Lee
Graphics processing unit (GPU) based fast calculation method for computer generated spherical hologram (CGSH) of a real-existing object is proposed. Three-dimensional (3D) point cloud is constructed by capturing a real-existing object from multiple directions using a depth camera. The GPU based calculation is used in both hologram generation part and numerical reconstruction part of the CGSH. The improved calculation efficiency is verified by comparing the computation speed between central processing unit (CPU) based and GPU based implementation. Graphics processing unit (GPU) based fast calculation method for computer generated spherical hologram (CGSH) of a real-existing object is proposed. Three-dimensional (3D) point cloud is constructed by capturing a real-existing object from multiple directions using a depth camera. The GPU based calculation is used in both hologram generation part and numerical reconstruction part of the CGSH. The improved calculation efficiency is verified by comparing the computation speed between central processing unit (CPU) based and GPU based implementation.
Chinese Optics Letters
- Publication Date: May. 28, 2014
- Vol. 12, Issue 6, 060016 (2014)
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