• Journal of the Optical Society of Korea
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• v.15 no.4
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• pp.357-361
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• 2011

Photon-counting sensing is a widely used technique for low-light-level imaging applications. This paper proposes a distance information extraction method with photon-counting passive sensing under low-lightlevel conditions. The photo-counting passive sensing combined with integral imaging generates a photon-limited elemental image array. Maximum-likelihood estimation (MLE) is used to reconstruct the photon-limited image at certain depth levels. The distance information is extracted at the depth level that minimizes the sum of the standard deviation of the corresponding photo-events in the elemental image array. Experimental and simulation results confirm that the proposed method can extract the distance information of the object under low-light-level conditions.

• KSBB Journal
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• v.26 no.1
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• pp.87-91
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• 2011

Automatic counting of yeast cells in baker's yeast culture was tried using a conventional light microscope equipped with a pc camera. Relatively good binary image was obtained by using white LED as microscope light source, but uneven brightness distribution in original image hindered counting accuracy. A block binarization method using local thresholds proportional to local brightnesses was used to get improved binary images. The brightnesses of the blocks were expressed as the value component in HSV color model. Good quality binary images were obtained by binarization on $8{\times}6$ blocks of original images and connected-component labelling of the binarized images produced reliable counting results in the concentration range $1.4{\times}10^5/mL{\sim}1.4{\times}10^7\;cells/mL$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.556-560
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• 1996

In order to examine thd accuracy of intersection counting method, the fiber orientation distribution of simulation figure platted by PC is measured using image processing. The fiber orientation distribution obtained by an image processing method is compared with those by the intersection counting method. The result shows that the errors of the intersection counting method are large because its measurement is made by the cross point of the scanning line and the fiber.

• East Asian mathematical journal
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• v.34 no.2
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• pp.85-101
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• 2018

The purpose of this paper is to investigate counting-based and collection-based computation of the elementary mathematics textbook in Korea and United States of America. As a results, we will provide some suggestive points through how to use and activity of number line, decomposing number, counting, grouping and so on by analyzing counting and collection-based computation in the elementary mathematics textbook of Korea and United States of America.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11b
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• pp.269-279
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• 2005

In this study, detectors characteristics for simultaneous counting of alpha and beta ray in a pipe were estimated. The detector were composed of thin ZnS(Ag) scintillator and plastic detector. The scintillator for counting alpha particles has been applied a polymer composite sheet, having a double layer structure of an inorganic scintillator ZnS(Ag) layer adhered onto a polymer sub-layer. The other for counting beta particles used a commercially available plastic scintillator. It was confirmed that the detectors were suitable for counting the in-pipe contamination.

• Journal of the Optical Society of Korea
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• v.12 no.2
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• pp.88-92
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• 2008

This paper discusses a photon-counting linear discriminant analysis (LDA) with computational integral imaging (II). The computational II method reconstructs three-dimensional (3D) objects on the reconstruction planes located at arbitrary depth-levels. A maximum likelihood estimation (MLE) can be used to estimate the Poisson parameters of photon counts in the reconstruction space. The photon-counting LDA combined with the computational II method is developed in order to classify partially occluded objects with photon-limited images. Unknown targets are classified with the estimated Poisson parameters while reconstructed irradiance images are trained. It is shown that a low number of photons are sufficient to classify occluded objects with the proposed method.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.231-236
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• 2007

In this paper, we studied the possibility of non-contact bill counting method using optical fiber sensor instead of traditionally used friction counting method. To implement non-contact counting, we designed and made optical fiber sensor and related parts. optical fiber sensor is made of optical fiber of 1mm diameter, photo diode and laser diode. Based on the conclusion which derived from preliminary experiment, instrument part is designed to make unevenness on the surface of bill paper and to stay parallel with optical fiber section. By analyzing the signal of optical sensor, we made counting program. Experimental instrument is composed of sensor part, instrument part, signal handling part. We checked the possibility of non-contact counting method after implementing experiment by using optical fiber sensor and instrument part.

• Journal of the Optical Society of Korea
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• v.20 no.5
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• pp.579-585
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• 2016

Integral imaging combined with photon-counting detection has been researched for three-dimensional information sensing under low-light-level conditions. This paper addresses the extraction of distance information with photon-counting integral imaging. The longitudinal distance to the object is obtained utilizing photon-counting elemental images. The pixel disparity is estimated by maximizing the nonlinear correlation of photocounts. The first- and second-order statistical properties of the nonlinear correlation are theoretically derived. In the experiments, these properties are verified by varying the mean number of photocounts in the scene. The average distance is compared to that from the intensity information, showing the robustness of the proposed system even at low photocounts.

• Journal of Information Processing Systems
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• v.16 no.1
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• pp.113-119
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• 2020

This study proposed the structure of the cluster's cell counting algorithm for cell analysis. The image required for cell count is taken under a microscope. At present, the cell counting algorithm is reported to have a problem of low accuracy of results due to uneven shape and size clusters. To solve these problems, the proposed algorithm has a feature of calculating the number of cells in a cluster by applying a radius change analysis to the existing distance conversion and watershed algorithm. Later, cell counting algorithms are expected to yield reliable results if applied to the required field.

• Journal of information and communication convergence engineering
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• v.19 no.4
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• pp.276-283
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• 2021

In this paper, we propose an effective noise reduction method for photon counting imaging using a discrete wavelet transform. Conventional 2D photon counting imaging was used to visualize the object under dark conditions using statistical methods, such as the Poisson random process. The photons in the scene were estimated using a statistical method. However, photons which disturb the visualization and decrease the image quality may occur in the background where there is no object. Although median filters are used to reduce the noise, the noise in the scene remains. To remove the noise effectively, our proposed method uses the discrete wavelet transform, which removes the noise in the scene using a specific thresholding method that utilizes photon counting imaging characteristics. We conducted an optical experiment to demonstrate the denoising performance of the proposed method.