• Journal of information and communication convergence engineering
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• v.11 no.4
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• pp.282-287
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• 2013

A real-time digital holographic display is the core technology for the next-generation 3DTV. Holographic display requires a considerably large amount of calculation. If generating a large number of digital holograms is intended, the amount of calculation and the time required increase exponentially. This is a significant obstacle in a real-time hologram service. This paper proposes an algorithm that increases the speed of generating a Fresnel hologram by using a recursive addition operation covering the entire coordinate array of a digital hologram. The 3D object designed to calculate the digital hologram uses a depth-map image produced by computer graphics. The proposed algorithm is a technique that performs the computer-generated holography (CGH) operation with only recursive addition of all of the hologram's coordinates by analyzing the regularity between the 3D object and the digital hologram coordinates. The experimental results show that the proposed algorithm increases the operation speed by 70% over the technique using the conventional CGH equation and by more than 30% over the previously proposed recursive technique.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.1
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• pp.129-139
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• 2013

In this paper, we proposed a new hardware architecture for calculating digital holograms at high speed, and verified it with field programmable gate array (FPGA). First, we rearranged memory scheduling and algorithm of computer generated hologram (CGH), and then introduced pipeline technique into CGH process. Finally we proposed a high-performance CGH processor. The hardware was implemented for the target of FPGA, which calculates a unit region of holograms, and it was verified using a hardware environment of NI Inc. and a FPGA of Xilinx Inc. It can generate a hologram of $16{\times}16$ size, and it takes about 4 sec for generating a hologram of a $1,024{\times}1,024$ size, using 6K point sources.

• Current Optics and Photonics
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• v.6 no.1
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• pp.51-59
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• 2022

Holographic display technology is one of the promising 3D display technologies. However, the large amount of computation time required to generate computer-generated holograms (CGH) is a major obstacle to the commercialization of digital hologram. In various systems such as multi-depth head-up-displays with hologram contents, it is important to transmit hologram data in real time. In this paper, we propose a rapid CGH computation method by applying an arraying of a down-scaled hologram with the multiplication of a shifted concave lens function array. Compared to conventional angular spectrum method (ASM) calculation, we achieved about 39 times faster calculation speed for 3840 × 2160 pixel CGH calculation. Through the numerical investigation and experiments, we verified the degradation of reconstructed hologram image quality made by the proposed method is not so much compared to conventional ASM.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.5
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• pp.548-554
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• 2009

We propose an automatic inspection system for hologram with multiple patterns. The system hardware consists of illuminations, camera, and vision processor. Multiple illuminations using LEDs are arranged in different directions to acquire each image of patterns. The system software consists of pre-processing, pattern generation, and pattern matching. The acquired images of input hologram are compared with their reference patterns by developed matching algorithm. To compensate for the positioning error of input hologram, reference patterns of hologram for different position should be generated in on-line. We apply a frequency transformation based CGH(computer-generated hologram) method to generate reference images. For the fast pattern matching, we also apply the matching method in the frequency domain. Experimental results for hologram of Korean currency are then presented to verify the usefulness of proposed system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5C
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• pp.386-394
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• 2008

For digital holographic video system, it is important to generate digital hologram as fast as possible. This paper proposed a fixed-point method and fast generation method that can calculate the Fresnel hologram using operation of whole-coordinate recursive addition. To compute the digital hologram, 3D object is assumed to be a collection of depth-map point generated using a PC. Our algorithm can compute a phase on a hologram by recursive addition with fixed-point format at a high speed. When we operated this algorithm on a personal computer, we could maximally compute digital hologram about 70% faster than conventional method and about 30% faster than of [3]'s method.