• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2280-2286
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• 2012

In this paper, we propose a novel nonlinear 3D image correlator using a fast computational integral imaging reconstruction (CIIR) method. In order to implement the fast CIIR method, the magnification process was eliminated. In the proposed correlator, elemental images of the reference and target objects are picked up by lenslet arrays. Using these elemental images, reference and target plane images are reconstructed on the output plane by means of the proposed fast CIIR method. Then, through nonlinear cross-correlations between the reconstructed reference and the target plane images, the pattern recognition can be performed from the correlation outputs. Nonlinear correlation operation can improve the recognition of 3D objects. To show the feasibility of the proposed method, some preliminary experiments are carried out and the results are presented by comparing the conventional method.

• Korean Journal of Optics and Photonics
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• v.19 no.4
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• pp.270-275
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• 2008

This paper addresses occluded object reconstruction and recognition with computational integral imaging (II). Integral imaging acquires and reconstructs target information in the three-dimensional (3D) space. The reconstruction is performed by averaging the intensities of the corresponding pixels. The distance to the object is estimated by minimizing the sum of the standard deviation of the pixels. We adopt principal component analysis (PCA) to classify occluded objects in the reconstruction space. The Euclidean distance is employed as a metric for decision making. Experimental and simulation results show that occluded targets are successfully classified by the proposed method.

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.181-182
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• 2008

In this paper, we propose a volumetric computational reconstruction method by use of smart pixel mapping technique in the computational integral imaging in order to overcome the problem of resolution degradation. The experimental results are presented to show the usefulness of our proposed technique.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.7
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• pp.1369-1375
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• 2016

In this paper, we present a depth extraction method of integral imaging using correlation between elemental images with phase only filter. Integral imaging is a passive three-dimensional (3D) imaging system records ray information of 3D objects through lenslet array by 2D image sensor, and displays 3D images by using the similar lenslet array. 2D images by lenslet array have different perspectives. These images are referred to as elemental images. Since the correlation can be calculated between elemental images, the depth information of 3D objects can be extracted. To obtain high correaltion between elemental images effectively, in this paper, we use phase only filter. Using this high correlation, the corresponding pixels between elemental images can be found so that depth information can be extracted by computational reconstruction technique. In this paper, to prove our method, we carry out optical experiment and calculate Peak Sidelobe Ratio (PSR) as a correlation metric.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2571-2578
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• 2014

In this paper, we propose a computational generation method of elemental images for time-multiplexed 3D integral imaging display based lens division. In the proposed method, we analyze the image formation between 3D object and elemental images based on ray optics. Based on the analyzed formation, we generate the elemental image set for time-multiplexed display. Positions of an object point picked up in proposed method is shifted for half size of lens divided from those in conventional method when generating elemental images. To show the usefulness of the proposed method, we carry out the preliminary experiments and present the results.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.251-252
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.113-114
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• 2008

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.191-192
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• 2008

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.280-280
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• 2006

• Journal of the Optical Society of Korea
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• v.17 no.6
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• pp.494-499
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• 2013

In this paper, we present an optical encryption and information authentication of 3D objects considering wireless channel characteristics. Using the optical encryption such as double random phase encryption (DRPE) and 3D integral imaging, a 3D scene with encryption can be transmitted. However, the wireless channel causes the noise and fading effects of the 3D transmitted encryption data. When the 3D encrypted data is transmitted via wireless channel, the information may be lost or distorted because there are a lot of factors such as channel noise, propagation fading, and so on. Thus, using digital modulation and maximum likelihood (ML) detection, the noise and fading effects are mitigated, and the encrypted data is estimated well at the receiver. In addition, using computational volumetric reconstruction of integral imaging and advanced correlation filters, the noise effects may be remedied and 3D information may be authenticated. To prove our method, we carry out an optical experiment for sensing 3D information and simulation for optical encryption with DRPE and authentication with a nonlinear correlation filter. To the best of our knowledge, this is the first report on optical encryption and information authentication of 3D objects considering the wireless channel characteristics.