• 제어로봇시스템학회논문지
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• 제14권5호
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• pp.426-431
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• 2008

In this paper, an improved AE system for digital still camera is proposed. AE system is auto exposure system to maintain optimized brightness of output image. But there is limitation for mobile devices to get high quality image with the conventional AE algorithm, because of organizational restriction of system. The conventional research has been studied only electronic shutter and AGC on the AE algorithm. In this paper, we suggest new AE algorithm included target setting, frame delay, Gamma Correction as well as electronic shutter and AGC to get high quality image. The proposed algorithm show improved result at control speed and ability of luminance expression.

• 대한기계학회논문집B
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• 제25권11호
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• pp.1535-1542
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• 2001

A high resolution digital cinematic Particle Image Velocimetry(PIV) has been developed. The system consists of a high speed CCD camera, a continuous Ar-ion laser and a computer with camera controller. To improve the spatial resolution, we adopt a Recursive Technique for velocity interrogation. At first, we obtain a velocity vector fur a larger interrogation window size based on the conventional two-frame cross-correlation PIV analysis using the FFT algorithm. Based on the knowing velocity information, more spatially resolved velocity vectors are obtained in the next iteration step with smaller interrogation windows. When the correct velocity vector at the first step is found to be critical, a Multiple Correlation Validation(MCV) technique is applied to decrease the spurious vectors. The MCV technique turns out to improve SNR(Signal to Noise Ratio) of the correlation table. The developed cinematic PIV method has been applied to the measurement of the unsteady flow characteristics of a Rushton turbine mixer. A total of 3,245 instantaneous velocity vectors were successfully obtained with 4 ms time resolution. The acquired spatial resolution corresponds to the conventional high resolution digital PIV system using a 1K ${\times}$ 1K CCD camera.

• 제어로봇시스템학회논문지
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• 제8권12호
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• pp.1036-1040
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• 2002

To process data of digital linescan camera, the frame grabber is essential to handle the data in low-level and in high speed more than 30 MHz stably. Traditional approaches to the development of hardware in vision system for the special purpose are mai y based on PC system, and are expensive and gigantic. Therefore, there are many difficulties in applying those in the field. So we investigate, in this paper, the implementation of FPGA for real-time processing of digital linescan camera. The system is not based on PC, but electronic device such as micropncessor. So it is expected that the use of FPGAs for low-level processing represents a fast, stable and inexpensive system. The experiments are carried out on the web guiding system in order to show the efficiency of the new image processor.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.61-68
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• 2008

A set of modal parameters of a stay-cable have been extracted from a moving picture captured by a digital camera supported by shaking hands. It is hard to identify the center of targets attached on the cable surface from the blurred cable motion image, because of the high speed motion of cable, low sampling frequency of camera, and the shaking effect of camera. This study proposes a multi-template matching algorithm to resolve such difficulties. In addition, a sensitivity-based system identification algorithm is introduced to extract the natural frequencies and damping ratios from the ambient cable vibration data. Three sets of vibration tests are conducted to examine the validity of the proposed algorithms. The results show that the proposed technique is pretty feasible for extracting modal parameters from the severely shaking motion pictures.

• 한국소음진동공학회논문집
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• 제18권12호
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• pp.1229-1236
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• 2008

A set of modal parameters of a stay-cable have been extracted fi:on a moving picture captured by a digital camera supported by shaking hands. It is hard to identify the center of targets attached on the cable surface from the blurred cable motion image, because of the high speed motion of cable, low sampling frequency of camera, and the shaking effect of camera. This study proposes a multi-template matching algorithm to resolve such difficulties. In addition, a sensitivity-based system identification algorithm is introduced to extract the natural frequencies and damping ratios from the ambient cable vibration data. Three sets of vibration tests are conducted to examine the validity of the proposed algorithms. The results show that the proposed technique is pretty feasible for extracting modal parameters from the severely shaking motion pictures.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1565-1567
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• 2004

Various defects are found in FPD (Flat Panel Display) manufacturing process. So detecting these defects early and reprocessing them is an important factor that reduces the cost of production. In this paper, the bare glass inspection system for the FPD which is the early process inspection system in the FPD manufacturing process is designed and implemented using the high performance and accuracy CCD line scan camera. For the preprocessing of the high speed line image data, the Image Processing Part (IPP) is designed and implemented using high performance DSP (Digital signal Processor), FIFO (First in First out), FPGA (Field Programmable Gate Array) and the Data Management and System Control part are implemented using ARM (Advanced RISC Machine) processor to control many IPP and cameras and to provide remote users with processed data. For evaluating implemented system, experiment environment which has an area camera for reviewing and moving shelf is made.

• 한국항공우주학회지
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• 제45권1호
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• pp.30-35
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• 2017

본 연구에서는 디지털 영상 상관 기법을 이용하여 알루미늄 하니콤 샌드위치 보의 고유 진동수를 계측하였다. 고속 디지털 카메라를 이용하여 보의 진동 영상을 획득하고 디지털영상 상관 기법을 이용하여 변위를 계산하였다. 시간 영역에서의 변위 데이터를 고속 퓨리에 변환하여 주파수 영역의 응답으로 변환하였다. 랜덤 가진에 따른 주파수 영역에서의 잡음을 줄이기 위하여 스펙트럼 평균화 기법과 Savitsky-Golay 디지털 필터를 사용하였다. 가속도계를 이용한 기존의 방법 및 유한요소 해석 결과와의 비교를 통하여 방법의 정확성을 확인하였다. 결론적으로 고속 디지털 카메라와 디지털 영상 상관 기법을 이용하는 새로운 방법은 구조물의 진동을 잘 측정할 수 있음을 보였고, 센서를 부착하기 어려운 바이오 구조 등의 진동 계측에 적용할 수 있을 것이다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.536-541
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• 2001

A high resolution digital cinematic Particle Image Velocimetry(PIV) has been developed. The system consists of a high speed CCD camera, a continuous Ar-ion laser and a computer with camera controller. To improve the spatial resolution, we adopt a Recursive Technique for velocity interrogation. At first, we obtain a velocity vector for a larger interrogation window size based on the conventional two-frame cross-correlation PIV analysis using the FFT algorithm. Based on the knowing velocity information, more spatially resolved velocity vectors are obtained in the next iteration step with smaller interrogation windows. The correct velocity vector at the first step is found to be critical, so we apply a Multiple Correlation Validation(MCV) technique in order to decrease the spurious vectors. The MCV technique turns out to improve SNR(Signal to Noise Ratio) of the correlation table. The developed cinematic PIV method has been applied to the measurement of the unsteady flow characteristics of a Rushton turbine mixer. A total of 3,245 instantaneous velocity vectors were successfully obtained with 4 ms time resolution. The acquired spatial resolution corresponds the performance of the conventional high resolution digital PIV system using a $1K{\times}1K$ CCD camera.

• Journal of the Optical Society of Korea
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• 제13권4호
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• pp.464-467
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• 2009

The grating projection method with phase-shifting technique is very useful in measuring the 3-dimensional (3D) shape with high accuracy and speed. In this work, we have developed an ultra high-speed digital laser grating projection system using a high-power laser diode and a highsensitivity CMOS camera. With our system, the optical measurement required to find out the profile of a 3D object could be carried out within 2.6 ms, which is a significant ($\sim$10 times) improvement compared with those of the previous studies.

• 한국콘텐츠학회논문지
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• 제12권12호
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• pp.135-145
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• 2012

네트워크 카메라 영상을 저장하는 DVR(Digital Video Recorder) 디자인 개발 연구 사례이다. 지금까지의 영상저장장치(DVR)는 아날로그 영상을 디지털 방식으로 변환 압축하여 저장하는 방식이었지만 앞으로는 네트워크 카메라를 통해 디지털 영상을 그대로 저장하는 방식으로 발전해 가고 있다. 또한 영상압축방식도 기존방식에서 고화질영상압축효율, 데이터크기 최소화, 네트워크와의 호환성, 제품의 처리속도 등을 고려한 제품들이 개발추세에 있다. 이에 따라 2012년에는 전 세계 네트워크 카메라와 영상처리장치의 판매 비율이 기존의 아날로그 방식의 제품군들을 크게 추월할 것으로 예상되며 이러한 기술 환경과 시장의 요구 변화에 있어서 기능구현, 신뢰성확보 등과 같이 품질 중심의 제품개발과 DVR의 개발 컨셉은 대형화되고 선명한 화질과 압축 기술의 향상으로 인하여 현재와는 다른 새로운 디자인을 요구하고 있으며, 제조사들은 사용자 중심의 제품디자인에 새로운 컨셉 방향으로 연구 개발하는 추세에 있다.