• Journal of the Optical Society of Korea
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• v.19 no.1
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• pp.102-111
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• 2015

This paper proposes an algorithm for recovering the colors of objects from multiple near-infrared (near-IR) images. The International Commission on Illumination (CIE) color coordinates of objects are recovered from a series of gray images captured under multiple spectral near-IR illuminations using polynomial regression. The feasibility of the proposed algorithm is tested experimentally by using 24 color patches of the Color Rendition Chart. The experimental apparatus is composed of a monochrome digital camera without an IR cut-off filter and a custom-designed LED illuminator emitting multiple spectral near-IR illuminations, with peak wavelengths near the red edge of the visible band, namely at 700, 740, 780, and 860 nm. The average color difference between the original and the recovered colors for all 24 patches was found to be 11.1. However, if some particular patches with high value are disregarded, the average color difference is reduced to 4.2, and this value is within the acceptability tolerance for complex image on the display.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.8
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• pp.625-632
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• 2002

We propose an outsole measurement/inspection system to improve the quality of the shoe product. It uses the Divide-and-Conquer technique to measure the length of shoes'outsole. First, it detects edge positions of outsole's toe and heel from each image frame using an unique scale block we defined and calculates the outsole's length as the distance of two edge positions. Then it compensates the total length of outsole using the side image of outsole. Next, it classifies the outsole as inferior goods if the measurement error is bigger than 5.8mm. As a result of testing with the various kinds of outsoles, it was shown that the 95% accuracy was acquired within 1mm allowable error range. In conclusion, the proposed inspection system is effective and useful in the measurement/inspection process of shoe product and any material object as well.

• International Journal of Fluid Machinery and Systems
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• v.8 no.2
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• pp.73-84
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• 2015

Aerating hydroturbines have recently been proposed as an effective way to mitigate the problem of low dissolved oxygen in the discharge of hydroelectric power plants. The design of such a hydroturbine requires a precise understanding of the dependence of the generated bubble size distribution upon the operating conditions (viz. liquid velocity, air ventilation rate, hydrofoil configuration, etc.) and the consequent rise in dissolved oxygen in the downstream water. The purpose of the current research is to investigate the effect of location of air injection on the resulting bubble size distribution, thus leading to a quantitative analysis of aeration statistics and capabilities for two turbine blade hydrofoil designs. The two blade designs differed in their location of air injection. Extensive sets of experiments were conducted by varying the liquid velocity, aeration rate and the hydrofoil angle of attack, to characterize the resulting bubble size distribution. Using a shadow imaging technique to capture the bubble images in the wake and an in-house developed image analysis algorithm, it was found that the hydrofoil with leading edge ventilation produced smaller size bubbles as compared to the hydrofoil being ventilated at the trailing edge.

• Journal of Navigation and Port Research
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• v.28 no.3
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• pp.233-238
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• 2004

Comer point is a very important information to a pattern recognition of image processing. And so, many researchers develope various detecting comer point algoritms. But, there are some problems to get comer points by 8 directional chain code when the degree of edge line is not integer multiplication of 45 degree. So, we propose a new algorithm which is combined with morphology and human visual conception for optimal comer points without the above defects. We get a good simulation result by this proposed algorithm Ana so, we think this algorithm is very useful to FA(factory automation} and ship's radar system to know some coastal area from its image.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.167-170
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• 2010

In this paper, we proposed a novel algorithm to detect the center of pupil in frontal view face. This algorithm, at first, extract an eye region from the face image using integral projection function and variance projection function. In an eye region, detect the center of pupil positions using circular hough transform with sobel edge mask. The experimental results show good performance in detecting pupil center from FERET face image.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.10
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• pp.703-713
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• 2004

This paper presents the new obstacle avoidance method that is composed of vision and sonar sensors, also a navigation algorithm is proposed. Sonar sensors provide poor information because the angular resolution of each sonar sensor is not exact. So they are not suitable to detect relative direction of obstacles. In addition, it is not easy to detect the obstacle by vision sensors because of an image disturbance. In This paper, the new obstacle direction measurement method that is composed of sonar sensors for exact distance information and vision sensors for abundance information. The modified splitting/merging algorithm is proposed, and it is robuster for an image disturbance than the edge detecting algorithm, and it is efficient for grouping of the obstacle. In order to verify our proposed algorithm, we compare the proposed algorithm with the edge detecting algorithm via experiments. The direction of obstacle and the relative distance are used for the inputs of the fuzzy controller. We design the angular velocity controllers for obstacle avoidance and for navigation to center in corridor, respectively. In order to verify stability and effectiveness of our proposed method, it is apply to a vision and sonar based mobile robot navigation system.

• Journal of the Korea Society of Computer and Information
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• v.9 no.4 s.32
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• pp.13-18
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• 2004

In this paper, we proposed a new digital watermarking technique. It uses frequency domain of discrete wavelet transform(DWT). watermarking technique is one of the most important tools for DRM(Digital Right Management) We proposed a new algorithm watermark insertion and detection. This technique cleats the watermark sequence using the edge image, spread spectrum technique and DWT. We tested the technique with various attacks. and found that it satisfies the watermarking evaluation criteria. Cox similarity measurement value is more than 6 on the Lena image and PSNR is more than 40dB on JPEG, Collusion. Clopping and Scatting. By the result, we proved that the new technique satisfies the requirement of Digital contents distribution, which are undeletablility tenacity, statistical undetectablility.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.598-604
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• 2012

Image signal is corrupted by various noises in image processing, many studies are being accomplished to restore those images. In this paper, we proposed a cascade filter algorithm for removing random valued impulse noise. The algorithm consists two steps that noise detection and noise elimination. Variance of filtering mask and center pixel variance are calculated for noise detection, and the noise pixel is replaced by estimated value which first apply switching self adaptive weighted median filter and finally processed by modified weight filter. Considering the proposed algorithm only remove noise and preserve the uncorrupted information that the algorithm can not only remove noise well but also preserve edge.

• Journal of Sensor Science and Technology
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• v.10 no.5
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• pp.286-291
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• 2001

We propose a new saliency map model for selecting an attended location in an arbitrary visual scene, which is one of the most important characteristics of human vision system. In selecting an attended location, an edge information can be considered as a feature basis to construct the saliency map. Edge filters are obtained from the independent component analysis(ICA) that is the best way to find independent edges in natural gray scenes. In order to reflect the non-uniform density in our retina, we use a multi-scaled pyramid input image instead of using an original input image. Computer simulation results show that the proposed saliency map model with multi-scale property successfully generates the plausible attended locations.

• Journal of the Korean Society for Heat Treatment
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• v.30 no.5
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• pp.222-226
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• 2017

Recently sapphire wafer has expected as smart phone cover material, however, brittle nature of sapphire needed edge grinding processes to prevent early initiation of cracks. Electro-deposited multi-layered groove tools with $35{\mu}m$ diamond particles were studied for sapphire wafer grinding. Solid particle flow behaviors in agitated electrolyte was studied using PIV(Particle Image Velocimetry), and uniform particle distribution in Ni bond were obtained when agitating impeller was located lower part of electrolyte. Hardness values of $400{\pm}50Hv$ were maintained for retention of diamond particles in electro-deposited bond layer. Sapphire wafer edge grinding test was carried out and multi-layered $160{\mu}m$ thick diamond tool showed much greater grinding capabilities up to 2000 sapphire wafers than single-layered $50{\mu}m$ thick diamond electro-deposited tools of 420 wafers. The reason why 3 times thicker multi-layered tools than single-layered tools showed 5 times longer tool lives in grinding processes was attributed to self-dressed new diamond particles in multi-layered tools, and multi-layered diamond tools could be promising for sapphire grinding.