Bandwidth-enhanced depth priority integral imaging using a band-limited diffusing illumination technique.
TL;DR: A bandwidth-enhanced depth priority integral imaging (DPII) technique is proposed and demonstrated and it is found that only a part of the input display bandwidth is used efficiently to present the 3D image in the traditional DPII system.
Abstract: The display bandwidth and display mechanism determine the performance of the three-dimensional (3D) display system. In this paper, a bandwidth-enhanced depth priority integral imaging (DPII) technique is proposed. Information transmission efficiency (ITE) defined as the output display bandwidth divided by the input display bandwidth is used to assess the II system. By analyzing the ITE, we find that only a part of the input display bandwidth is used efficiently to present the 3D image in the traditional DPII system. The DPII system sacrifices the ITE for depth enhancement. The low ITE that fundamentally limits the 3D performance of the DPII system is ascribed to the diffusing illumination mechanism of the display system. To enhance the 3D performance, a collimated illumination DPII system as a special case of band-limited diffusing illumination technique has been proposed and demonstrated first. The bandwidth and ITE of such a DPII system are increased. The depth of field (DOF) of the system is doubled. The resolution of the 3D image is increased to the level of the resolution priority II system without sacrificing the viewing angle. A more general case, band-limited illumination DPII system is also demonstrated. By modulating the divergence angle of the illumination system, the 3D image’s resolution and DOF can be controlled. The bandwidth and ITE of the DPII system using band-limited illumination are also higher than that of the traditional DPII system. Experiments are presented to prove the bandwidth-enhanced mechanism of the DPII system.
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TL;DR: In this article, a quantitative beam analysis approach is proposed, and a diffusing model is established to analyze the influence of the position and diffusing-angle of the holographic diffuser on different reconstruction points.
9 citations
TL;DR: A method to enhance the performance of an integral imaging system is demonstrated using the time-multiplexed convergent backlight technique, which increases the space bandwidth of the integral Imaging system and increases the resolution, depth of field, and viewing angle simultaneously.
Abstract: A method to enhance the performance of an integral imaging system is demonstrated using the time-multiplexed convergent backlight technique. The backlight increases the space bandwidth of the integral imaging system. As a result, the resolution, depth of field, and viewing angle of the integral imaging system are increased simultaneously. The cross-talk noise is also decreased without using any optical barrier. One part of the added space bandwidth comes from the optimized illumination. The other part is converted from the time bandwidth of the system by time-multiplexing. The time-multiplexed convergent backlight modulates the direction of the backlight in time sequence to illuminate the elemental images. Then, the elemental images synthesize the 3D images using a microlens array. An elemental images rendering method using a conjugate pinhole camera and pinhole projector model is designed to dynamically match the illumination direction. The rendering method eliminates the distortion and maximizes the viewing angle and viewing zone. A field programmable gate array (FPGA)-based controller is used to manage and synchronize the time sequence of the backlight and the display devices. Using this technique, high-performance 3D images are realized. Comparison experiments of the integral imaging system using diffused backlight and convergent backlight are performed. The results show the effectiveness of the proposed technique.
6 citations
TL;DR: In this article, a 3D display system consisting of a collimated backlight source, a 31.5-inch LCD with the resolution of 3840 × 2160, an aspherical cylindrical compression lens (ACCL) array and a holographic functional screen (HFS) is demonstrated.
4 citations
TL;DR: To reduce the view-flipping effect and enhance the viewing resolution, the modulation characteristics of the hogel based holographic stereogram is constructed and validated and the results indicate that decreasing the size of hogel is beneficial to the reduction of the view flipping, however, which will result in significant diffraction effect which can degrade the reconstruction quality.
Abstract: To reduce the view-flipping effect and enhance the viewing resolution, the modulation characteristics of the hogel based holographic stereogram is constructed and validated. The performance of the view-flipping effect is analyzed, and the results indicate that decreasing the size of hogel is beneficial to the reduction of the view flipping, however, which will result in significant diffraction effect which can degrade the reconstruction quality. Furthermore, a diffraction-limited imaging model of the hogel based holographic stereogram is established, where both the limited aperture of the hogel and the defocused aberration of the object point are introduced, and the effective resolvable size of the reconstructed image point is simulated. The theory shows that there is an optimal hogel size existed for the certain depth of scene. Both the numerical and optical experiments are implemented, and the results are well agreed with the theoretical prediction, which demonstrates that the view-flipping reduction and reconstruction visualization enhancement for EPISM based holographic stereogram can be achieved when the proper size of hogel is utilized.
3 citations
TL;DR: In this article, a tomographic display with integral imaging (InIm) technology is proposed to generate a high-resolution volumetric scene, and InIm makes it possible for the scene to be reconstructed on a large screen through a projection.
Abstract: We introduce a projection-type light field display featuring effective light modulation. By combining a tomographic display with integral imaging (InIm) technology, a novel optical design is capable of an autostereoscopic light field projector. Here, the tomographic approach generates a high-resolution volumetric scene, and InIm makes it possible for the volumetric scene to be reconstructed on a large screen through a projection. Since all the processes are realized optically without digital processing, our system can overcome the performance limitations associated with the number of pixels in the conventional InIm displays. We built a prototype display and demonstrated that our optical design has the potential of massive resolution with a full-parallax in a single device.
3 citations
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TL;DR: A new super multi-view (SMV) display system that enables the number of views to be increased is proposed that was used to construct a SMV display having 256 views.
Abstract: A new super multi-view (SMV) display system that enables the number of views to be increased is proposed. All three-dimensional (3D) images generated by multiple multi-view flat-panel displays are superimposed on a common screen using a multi-projection system. The viewing zones of the flat-panel 3D display are produced in the pupils of the projection lenses and then imaged to the observation space by a screen lens. Sixteen flat-panel 3D displays having 16 views were used to construct a SMV display having 256 views. The 3D resolution was 256 x 192. The screen size was 10.3 inches. The horizontal interval of the viewing zones was 1.3 mm.
254 citations
TL;DR: An integral imaging method to enhance the depth of a three-dimensional image by displaying it throughout real and virtual image fields by maximizing the product of depth and resolution square of the displayed three- dimensional image.
Abstract: We present an integral imaging method to enhance the depth of a three-dimensional image by displaying it throughout real and virtual image fields. When the product of depth and resolution square of the displayed three-dimensional image is used as a figure of merit in integral imaging systems, our method can maximize this merit especially when three-dimensional images with large depth of focus are displayed. The feasibility of our method is experimentally demonstrated by generation of elemental images by a computer.
164 citations
TL;DR: This work manufactured a lens array for the display device, and here it is presented experimental results on using two SXGA projectors to create a high-resolution image and project the resultant image onto a small screen by using long-zoom-lens projection optics.
Abstract: Integral videography (IV) is an animated extension of integral photography. Despite IV's many advantages, the quality of its spatial images has thus far been poor; the pixel pitch of the display and the lens pitch are considered to be the main factors affecting the IV image format. Our solution for increasing pixel density is to use multiple projectors to create a high-resolution image and project the resultant image onto a small screen by using long-zoom-lens projection optics. We manufactured a lens array for the display device, and here we present experimental results on using two SXGA projectors. The pixel pitch and lens pitch of the new display are 85 mum and 1.016 mm, respectively. The multiprojector IV display device has a spatial resolution of approximately 1, 2, and 3 mm for image depths of 10, 35, and 60 mm, respectively, in front of and behind the lens array.
156 citations
TL;DR: In this article, a time-multiplexed integral-imaging method that enhances both the depth of focus and the resolution of a 3D image by displaying it with an array of lenslets with different focal lengths and aperture sizes was proposed.
Abstract: Conventional integral-imaging systems utilize lenslet arrays with fixed focal lengths and aperture sizes. We propose a time-multiplexed integral-imaging method that enhances both the depth of focus and the resolution of a three-dimensional image by displaying it with an array of lenslets with different focal lengths and aperture sizes. The nonuniform lenslet parameters (focal lengths and aperture sizes) for our method are calculated. Our theoretical analysis indicates that significant improvements in both depth of focus and resolution can be obtained with the proposed technique.
133 citations
04 Feb 2011
TL;DR: It is demonstrated that either laser or light-emitting diode (LED) illumination is feasible, and Multi-SLM designs, especially over curved surfaces, relieve high bandwidth requirements, and therefore, are strong candidates for futuristic holographic video displays.
Abstract: Holography aims to record and regenerate volume filling light fields to reproduce ghost-like 3-D images that are optically indistinguishable from their physical 3-D originals. Digital holographic video displays are pixelated devices on which digital holograms can be written at video rates. Spatial light modulators (SLMs) are used for such purposes in practice; even though it is desirable to have SLMs that can modulate both the phase and amplitude of the incident light at each pixel, usually amplitude-only or phase-only SLMs are available. Many laboratories have reported working prototypes using different designs. Size and resolution of the SLMs are quite demanding for satisfactory 3-D reconstructions. Space-bandwidth product (SBP) seems like a good metric for quality analysis. Even though moderate SBP is satisfactory for a stationary observer with no lateral or rotational motion, the required SBP quickly increases when such motion is allowed. Multi-SLM designs, especially over curved surfaces, relieve high bandwidth requirements, and therefore, are strong candidates for futuristic holographic video displays. Holograms are quite robust to noise and quantization. It is demonstrated that either laser or light-emitting diode (LED) illumination is feasible. Current research momentum is increasing with many exciting and encouraging results.
126 citations