• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.121-125
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• 1990

Optical Hough transform technique is introduced to obtain the straight line features in parallel from the input scene images. Experimental results are also provided to demonstrate the advantage of such optical parallel processor over the digital one. Peaks in optical Hough space are free from quantization noise and thus easy to detect.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.66-67
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• 2001

We explain a method to obtain optical Hough transform filters by use of multiplexed holograms and how they are used for optical pattern recognition.

• Korean Journal of Optics and Photonics
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• v.9 no.5
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• pp.321-325
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• 1998

We explain that a holographic filter of the generalized Hough transform can be easily obtained by use of rotational multiplexing in hologram recording. To show the feasibility of our approach experimentally, we recorded the Hough transform filter of both line and circle parameterization by combined use of rotational and angle multiplexing. Experimental results on the Hough transform for a few input patterns are presented.

• Proceedings of the Optical Society of Korea Conference
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• 1997.08a
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• pp.6-6
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• 1997

• International Journal of Control, Automation, and Systems
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• v.1 no.1
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• pp.119-126
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• 2003

The problem of tracking moving objects in a video stream is discussed in this pa-per. We discussed the popular technique of optical flow for moving object detection. Optical flow finds the velocity vectors at each pixel in the entire video scene. However, optical flow based methods require complex computations and are sensitive to noise. In this paper, we proposed a new method based on the Hough transform and on voting accumulation for improving the accuracy and reducing the computation time. Further, we applied the Boo-lean based edge detector for edge detection. Edge detection and segmentation are used to extract the moving objects in the image sequences and reduce the computation time of the CHT. The Boolean based edge detector provides accurate and very thin edges. The difference of the two edge maps with thin edges gives better localization of moving objects. The simulation results show that the proposed method improves the accuracy of finding the optical flow vectors and more accurately extracts moving objects' information. The process of edge detection and segmentation accurately find the location and areas of the real moving objects, and hence extracting moving information is very easy and accurate. The Combinatorial Hough Transform and voting accumulation based optical flow measures optical flow vectors accurately. The direction of moving objects is also accurately measured.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.3
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• pp.39-47
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• 2000

In this paper, we propose a new method of finding the true length of the line and long axis of the ellipse at the $\theta$=$\theta$o＋ 90$^{\circ}$ and short axis of the ellipse at the $\theta$ = $\theta$o from the Hough transform (HT) results. Through the simulations, we showed that the true length of the line and ellipse could be obtained with 98 % accuracy by using the distance from the maximum envelope to the minimum envelope. To compare the simulation results with the experimental results, we performed optical experiments by using a HT CGH filter. Through the experiments, we showed that our results were very similar to those of the simulation.

• Korean Journal of Optics and Photonics
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• v.12 no.1
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• pp.55-60
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• 2001

We propose a method to extract features optically from the input pattern by use of an array of Hough transfOllli filters. Here the subparts of the input pattern are Hough-transformed by. their cOlTesponding elements of the filter array independently and simultaneously. Compared with the conventional method, in which the whole input pattern is Hough-transformed by a single optical filter, the proposed method not only provides the improved optical transform results when the input pattern becomes complex but also extracts the approximate position information of the line segment features. To show the feasibility of this approach, we fabricated a $5\times5$ filter array and performed preliminary experiments.iments.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.11
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• pp.64-69
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• 1997

We have shown that the Hough transform filter can be easily obtained by repeatedly recording one line segment pattern holographically by use of rotational multiplexing. With this filter, one can get resutls of the hough transform in the time of light propagation. To demonstrate our method experimentally, the hough transform filter for 18 different rottion angles was recorded, and experimental transform results were compared with simulated ones for a few input patterns. By introducing a compensation process for the non-uniformity of both the input plane wav eand the diffraction efficiency of each hologram. It is possible to get more precise transform results.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.301-304
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• 1999

In this paper, we proposed the new method of extracting the position and the length of the input-line by using only two parameters ($\theta$, $\rho$) from the HT(Hough Transform) data. The computer simulations and the optical experiments by using the HT CGH(Computer Generated Hologram) filter is perfermed. The results are very similar to those of the computer simulation results.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.931-934
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• 2000

입력영상의 Hough 변환(Hough Transform; HT) 영상으로부터 입력영상인 원호의 중심각의 크기, 반지름의 길이 및 양 끝점의 위치 정보를 구하는 방법을 제안하였다. HT 영역에서 포락선의 정보로부터 원호영상의 외접사각형의 가로 및 세로 길이와 회전 각도를 구한 다음 이로부터 원호영상 정보를 계산하였다.