Munkh-Uchral Erdenebat

High speed image space parallel processing for computer-generated integral imaging system

In an integral imaging display, the computer-generated integral imaging method has been widely used to create the elemental images from a given three-dimensional object data. Long processing time, however, has been problematic especially when the three-dimensional object data set or the number of the elemental lenses are large. In this paper, we propose an image space parallel processing method, which is implemented by using Open Computer Language (OpenCL) for rapid generation of the elemental images sets from large three-dimensional volume data. Using the proposed technique, it is possible to realize a real-time interactive integral imaging display system for 3D volume data constructed from computational tomography (CT) or magnetic resonance imaging (MRI) data.

Real-time 3D display system based on computer-generated integral imaging technique using enhanced ISPP for hexagonal lens array

This paper proposes an open computer language (OpenCL) parallel processing method to generate the elemental image arrays (EIAs) for hexagonal lens array from a three-dimensional (3D) object such as a volume data. Hexagonal lens array has a higher fill factor compared to the rectangular lens array case; however, each pixel of an elemental image should be determined to belong to the single hexagonal lens. Therefore, generation for the entire EIA requires very large computations. The proposed method reduces processing time for the EIAs for a given hexagonal lens array. By using the proposed image space parallel processing (ISPP) method, it can enhance the processing speed that generates the 3D display of real-time interactive integral imaging for hexagonal lens array. In our experiment, we implemented the EIAs for hexagonal lens array in real-time and obtained a good processing time for a large of volume data for multiple cases of lens arrays.

Resolution-enhancement for an orthographic-view image display in an integral imaging microscope system.

Due to the limitations of micro lens arrays and camera sensors, images on display devices through the integral imaging microscope systems have been suffering for a low-resolution. In this paper, a resolution-enhanced orthographic-view image display method for integral imaging microscopy is proposed and demonstrated. Iterative intermediate-view reconstructions are performed based on bilinear interpolation using neighborhood elemental image information, and a graphics processing unit parallel processing algorithm is applied for fast image processing. The proposed method is verified experimentally and the effective results are presented in this paper.

Resolution enhancement of integral‐imaging three‐dimensional display using directional elemental image projection

— A new approach to resolution enhancement of an integral-imaging (II) three-dimensional display using multi-directional elemental images is proposed. The proposed method uses a special lens made up of nine pieces of a single Fresnel lens which are collected from different parts of the same lens. This composite lens is placed in front of the lens array such that it generates nine sets of directional elemental images to the lens array. These elemental images are overlapped on the lens array and produce nine point light sources per each elemental lens at different positions in the focal plane of the lens array. Nine sets of elemental images are projected by a high-speed digital micromirror device and are tilted by a two-dimensional scanning mirror system, maintaining the time-multiplexing sequence for nine pieces of the composite lens. In this method, the concentration of the point light sources in the focal plane of the lens array is nine-times higher, i.e., the distance between two adjacent point light sources is three times smaller than that for a conventional II display; hence, the resolution of three-dimensional image is enhanced.

Development of a real-time integral imaging display system based on graphics processing unit parallel processing using a depth camera

Abstract. 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.

Real-time interactive display for integral imaging microscopy

A real-time interactive orthographic-view image display of integral imaging (II) microscopy that includes the generation of intermediate-view elemental images (IVEIs) for resolution enhancement is proposed. Unlike the conventional II microscopes, parallel processing through a graphics processing unit is required for real-time display that generates the IVEIs and interactive orthographic-view images in high speed, according to the user interactive input. The real-time directional-view display for the specimen for which 3D information is acquired through II microscopy is successfully demonstrated by using resolution-enhanced elemental image arrays. A user interactive feature is also satisfied in the proposed real-time interactive display for II microscopy.

Integral imaging microscopy with enhanced depth-of-field using a spatial multiplexing.

A depth-of-field enhancement method for integral imaging microscopy system using a spatial multiplexing structure consisting of a beamsplitter with dual video channels and micro lens arrays is proposed. A computational integral imaging reconstruction algorithm generates two sets of depth-sliced images for the acquired depth information of the captured elemental image arrays and the well-focused depth-slices of both image sets are combined where each is focused on a different depth plane of the specimen. A prototype is implemented, and the experimental results demonstrate that the depth-of-field of the reconstructed images in the proposed integral imaging microscopy is significantly increased compared with conventional integral imaging microscopy systems.

Integral-floating Display with 360 Degree Horizontal Viewing Angle

A three-dimensional integral-floating display with 360 degree horizontal viewing angle is proposed. A lens array integrates two-dimensional elemental images projected by a digital micro-mirror device, reconstructing three-dimensional images. The three-dimensional images are then relayed to a mirror via double floating lenses. The mirror rotates in synchronization with the digital micro-mirror device to direct the relayed three-dimensional images to corresponding horizontal directions. By combining integral imaging and the rotating mirror scheme, the proposed method displays full-parallax three-dimensional images with 360 degree horizontal viewing angle.

Advanced 360-Degree Integral-Floating Display Using a Hidden Point Removal Operator and a Hexagonal Lens Array

An enhanced 360-degree integral-floating three-dimensional display system using a hexagonal lens array and a hidden point removal operator is proposed. Only the visible points of the chosen three-dimensional point cloud model are detected by the hidden point removal operator for each rotating step of the anamorphic optics system, and elemental image arrays are generated for the detected visible points from the corresponding viewpoint. Each elemental image of the elemental image array is generated by a hexagonal grid, due to being captured through a hexagonal lens array. The hidden point removal operator eliminates the overlap problem of points in front and behind, and the hexagonal lens array captures the elemental image arrays with more accurate approximation, so in the end the quality of the displayed image is improved. In an experiment, an anamorphic-optics-system-based 360-degree integral-floating display with improved image quality is demonstrated.

Integral floating-image display using two lenses with reduced distortion and enhanced depth

— An integral floating display (IFD) with a long depth range without floating lens distortion is proposed. Two lenses were used to reduce barrel distortion of the floating lens and three-dimensional (3-D) image deformation from object-dependent longitudinal and lateral magnifications in the floating-display system, combined with an integral imaging display. The distance between the floating lenses is the sum of their focal lengths. In the proposed configuration, lateral and longitudinal magnifications are constant regardless of the distance of the integrated 3-D images, so the distortions from the distant-dependent magnifications of the floating lens do not occur with the proposed method. In addition, the proposed floating system expands the depth range of the integral imaging display. As a result, the display can show a correct 3-D floating image with a large depth range. Experimental results demonstrate that the proposed method successfully displays a 3-D image without floating lens distortions across a large depth range.