• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1689-1692
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• 2003

본 논문에서는 홍채인식 시스템에서 효율적인 영상을 획득을 위한 이미지 기반 자동초점 계산방법을 제안한다. 제안된 방법은 동공 영역을 중심으로 Block단위로 이미지 기반 초점 계수를 조합하여 Out-of-Focusing 현상이나 노이즈의 간섭을 줄여줄 수 있다. 22800장의 홍채 영상을 이용한 실험 결과를 통해 제안하는 방법이 약 95%의 효율성을 가짐을 증명하였다.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05d
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• pp.882-885
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• 2002

디지털 영상의 소유권을 보호하기 위해 웨이블렛 변환을 이용하여 시각적으로 인식할 수 없는 부분에 워터마크를 삽입하는 알고리즘을 제안하였다. 본 논문에서는 잡음의 분산이 커질수록 유사도는 감소했으나 분산이 100으로 상당히 큰 범위임에도 불구하고, 제안한 방법의 경우 87%이상의 유사도를 검출해냈다. 이에 비해 Cox 방법의 경우 54%정도로 낮은 유사도를 검출해 내고 있다. 결과적으로 제안한 방법이 COX의 방법보다 잡음에 대한 워터마크의 견고성이 향상되었음을 알수 있었다.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.179-185
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• 2001

In this study, a visual sensor system for weld seam tracking the I-butt weld joints in GMA welding was constructed. The sensor system consists of a CCD camera, a diode laser with a cylindrical lens and a band-pass-filter to overcome the degrading of image due to spatters and arc light. In order to obtain the enhanced image, quantitative relationship between laser intensity and iris number was investigated. Throughout the repeated experiments, the shutter speed was set at 1-milisecond for minimizing the effect of spatters on the image, and therefore most of the spatter trace in the image have been found to be reduced. Region of interest was defined from the entire image and gray level of searched laser line was compared to that of weld line. The differences between these gray levels lead to spot the position of weld joint using central difference method. The results showed that, as long as weld line was within $^\pm$15$^\circ$from the longitudinal straight fine, the system constructed in this study could track the weld line successful1y. Since the processing time reduced to 0.05 sec, it is expected that the developed method could be adopted to high speed welding such as laser welding.

• Journal of Mechanical Science and Technology
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• v.19 no.10
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• pp.1856-1863
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• 2005

In this study, a visual sensor system for weld seam tracking the I-butt weld joints in GMA welding was constructed. The sensor system consists of a CCD camera, a diode laser with a cylindrical lens and a band-pass-filter to overcome the degrading of image due to spatters and arc light. In order to obtain the enhanced image, quantitative relationship between laser intensity and iris opening was investigated. Throughout the repeated experiments, the shutter speed was set at 1/1000 second for minimizing the effect of spatters on the image, and therefore the image without the spatter traces could be obtained. Region of interest was defined from the entire image and gray level of the searched laser stripe was compared to that of weld line. The differences between these gray levels lead to spot the position of weld joint using central difference method. The results showed that, as long as weld line is within $\pm15^{o}$ from the longitudinal straight line, the system constructed in this study could track the weld line successfully. Since the processing time is no longer than 0.05 sec, it is expected that the developed method could be adopted to high speed welding such as laser welding.

• The Journal of the Korea Contents Association
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• v.14 no.4
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• pp.1-8
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• 2014

The virtual avatar is a principal way as media for communicating language and affective feelings in virtual environment. As similar purpose, this study evaluates user's visual feeling according to the changes of iris color and pupil size of virtual avatar which is considered as new factors for representing realistic avatar. Virtual avatars were configured by pupil accommodation and iris color(green, brown). After presenting above image to 32 participants, a questionnaire(18 items) based on previous studies was created, and reported as a 5-point scale. Experimental result showed that the case of adopting pupil accommodation induced more realistic visual feeling of subjects. This result can be regarded as a basis for designing realistic virtual avatar by confirming the effectiveness of pupil accommodation of avatar in terms of representing visual presence.

• The Journal of the Korea Contents Association
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• v.6 no.1
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• pp.143-150
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• 2006

Recently, the fields such as internet banking and electronic commerce are more and more growing due to the growth of practical use of personal computer and the progress of communication technology, So importance of information security has been increased. In fact, traditional identification systems are inherently insecure because the personal identification information can be forgotten, stolen or lost. In this paper, we propose an identification system that can decide whether the user is registered based on iris information using a mouse. The proposed system is mounted a CCD camera and an illumination device on general type mouse. Then it decides whether the user is registered after the acquired image are processed and analyzed. This system gives a PC user the advantage of low-cost and convenience without necessity preparing high-cost equipment for biometrics when using a identification system.

• Korean Journal of Optics and Photonics
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• v.11 no.6
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• pp.390-394
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• 2000

An optical system for iris pattern recognition of the human eye is designed. The lens system is triplet type, and characterized to minimize longitudinal chromatic aberration and Petzval sum. The distance from object to image is 200 mm-300 mm and the effective focal length is 50 mm. Performance of the imaging system is assessed by calculating the ray-fan and spot diagram for Fraunhofer C, d and F line for object height 0 mm, 4 mm and 6 mm. Furthermore, MTFs are calculated. All of the spot sizes are less than 0.05 mm in diameter. The MTF values are higher than 0.5 in the spatial frequency range up to 20 lines/mm for all of the object heights. ights.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.2
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• pp.3-11
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• 2010

In this paper we propose a new algorithm to detect the irises of both eyes from a human face. Using the separability filter, the algorithm first extracts blobs(intensity valleys) as the candidates for the irises. Next, for each pair of blobs, the algorithm computes a cost using Hough transform and separability filter to measure the fit of the pair of blobs to the image. And then, the algorithm selects a pair of blobs with the smallest cost as the irises of both eyes. As the result of the experiment using 150 faces images without spectacles, the success rate of the proposed algorithm was 97.3% for the best case and 95.3% for the worst case.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.526-534
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• 2006

In this paper we propose a new algorithm to detect the irises of both eyes from a human face. Using the separability filter, the algorithm first extracts blobs(intensity valleys) as the candidates for the irises. Next, for each pair of blobs. the algorithm computes a cost usings Hough transform and separability later to measure the fit of the pair of blobs to the image. And then, the algorithm selects a pair of blobs with the smallest cost as the irises of both eyes. As the result of the experiment using 150 faces images without spectacles, the success rate of the proposed algorithm was 97.3% for the best case and 95.3% for the worst case.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.7
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• pp.1291-1300
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• 2008

In this paper, we propose a intelligent system to improve the accuracy of pattern recognition. The proposed intelligent system consist in SOFM, LVQ and FCM algorithm. We are confirmed the effectiveness of the proposed intelligent system through the several experiments that classify Fisher's Iris data and face image data that offered by ORL of Cambridge Univ. and EMG data. As the results of experiments, the proposed intelligent system has better accuracy of pattern recognition than general LVQ.