• Proceedings of the KIEE Conference
• /
• 1999.11c
• /
• pp.674-676
• /
• 1999

본 연구에서는 시각센서를 이용하여 CAD데이터와 측정치와의 오차를 실시간으로 판정하여 다양한 형태의 불량검사 및 부품분류를 할 수 있는 2D 측정용 Machine Vision System을 개발하였다. 또한, 본 시스템은 품질검사 및 수율 관리를 하여 제품의 품질을 향상시킬 수 있도록 하기 위한 품질관리 제어시스템이다. 이를 위하여, 고성능 카메라와 서브픽셀, 레이블링, 켈리브레이션등의 최첨단 영상처리 기술을 개발하여 고속 온-라인 상에서 가공물의 치수를 정확하게 측정(10 ${\mu}m$ 단위)할 수 있도록 하였다.

• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.5
• /
• pp.493-498
• /
• 2007

In this paper, a 2-dimensional accurate edge-based matching algorithm using subpixel edges is proposed that combines the Generalized Hough Transform(GHT) and the Chamfer matching to complement the weakness of either method. First, the GHT is used to find the approximate object positions and orientations, and then these positions and orientations are used as starting parameter values to find more accurate position and orientation using the Chamfer matching with distance interpolation. Finally, matching accuracy is further refined by using a subpixel algorithm. Testing results demonstrate that greater matching accuracy is achieved using subpixel edges rather than edge pixels.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.17 no.1
• /
• pp.94-99
• /
• 2007

In this paper, a 2-dimensional edge-based matching algorithm is proposed that combines the generalized Hough transform (GHT) and the Chamfer matching to complement weakness of either method. First, the GHT is used to find approximate object positions and orientations, and then these positions and orientations are used as starling parameter values to find more accurate position and orientation using the Chamfer matching. Finally, matching accuracy is further refined by using a subpixel algorithm. The algorithm was implemented and successfully tested on a number of images containing various electronic components.

• Journal of Advanced Marine Engineering and Technology
• /
• v.20 no.4
• /
• pp.90-100
• /
• 1996

To maintain high spacial accuracy and rapid CPU time in interpolating data from grid to random position or inversely in PIV, proposed many technuques are compared and discussed mainly in terms of interpolating error and computing time. And artificial PIV atmosphere data is furnished by CFD result. First, for interpolation from grid to random position, multiquadric method gives the highest accuracy with the longest CPU time and Taylor series expansion methods give reasonable accuracy with less calculating load. Secondly, the sub-pixel resolution analysis in estimating the coordinates of the maximum correlation coefficients essential in the grey level correlation PIV reveal that 8-neighbours 2nd-order least square interpolation gives utmost accuracy in terms of the real flow conditions.

• Journal of Advanced Marine Engineering and Technology
• /
• v.20 no.4
• /
• pp.412-412
• /
• 1996

To maintain high spacial accuracy and rapid CPU time in interpolating data from grid to random position or inversely in PIV, proposed many technuques are compared and discussed mainly in terms of interpolating error and computing time. And artificial PIV atmosphere data is furnished by CFD result. First, for interpolation from grid to random position, multiquadric method gives the highest accuracy with the longest CPU time and Taylor series expansion methods give reasonable accuracy with less calculating load. Secondly, the sub-pixel resolution analysis in estimating the coordinates of the maximum correlation coefficients essential in the grey level correlation PIV reveal that 8-neighbours 2nd-order least square interpolation gives utmost accuracy in terms of the real flow conditions.

• Journal of Korea Game Society
• /
• v.20 no.3
• /
• pp.65-74
• /
• 2020

In the shadow map method, if the shadow map is magnified, the shadow has a jagged silhouette. Herein, we propose a soft shadow method that filters reshaped silhouettes analytically. First, the shadow silhouette is reshaped through sub-texel edge detection, which is based on linear or quadratic curve models. Second, an integral shadow filtering algorithm is used to accurately obtain the average shadow intensity from a definite integral estimation. The implementation demonstrates that our solution can effectively eliminate jagged aliasing and efficiently generate soft shadows.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.135-136
• /
• 2015

일반적으로 머신비전을 이용한 위치 추정 정밀도는 카메라의 화소 수에 비례한다. 머신비전 카메라의 경우 화소가 많을수록 카메라 가격이 크게 증가하므로 화소 수만을 늘려서 정밀도를 높이는 하드웨어적 방법은 활용이 제한적이다. 이런 문제를 해결하기 위해서 적은 화소 수로 높은 위치 추정 정밀도를 얻을 수 있는 다양한 소프트웨어 알고리즘에 대한 연구가 진행되어 왔다. 본 논문에서는 위치 추정 정밀도를 높이기 위한 서브 픽셀 위치 추정 알고리즘을 구현하고 이를 반도체 칩 검사용 고정밀 스테이지에 적용하였다.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.38 no.5
• /
• pp.70-78
• /
• 2001

We have developed a novel driving system of 5' true color FED using voltage controlled PWM method which has current control effect. The proposed method has the advantage of voltage controlled pulse width modulation method and current control method. Also, we propose a new circuit model of FED subpixel for circuit simulation of FED driving circuits, considering some parasitic effects, i.e., cross talk, line coupling effect and leakage current to the adjacent cathode lines. Output stage of the data driving circuit is optimized using the proposed circuit model. In video data processing, FED controller uses the parallel processing of R.G.B input data, so duty ratio is maximized and brightness of FED increases. With this results, no noise and high quality performance is achieved in display of 5' true color FED.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.10
• /
• pp.135-141
• /
• 2013

In this paper, we installed three high brightness red, green, and blue LED in one socket and made one pixel unit. And we also developed the full-color display board module and control unit which can express various images such as text, graphics, video image with the combination of pixel units and a number of modules. LED display driver module have a driver circuit within the combination of the RGB pixel dot on unit area. These modules of the existing form can be high priced because of implementation a fixed resolution in specific space and installation space. To overcome these shortcomings, we developed a LED driver and LED pixel modules free in array at random pitch intervals. Display board module of this paper enabled to display smoothly video image which have many data processing quantity through dragging data speed up 36 frames per second. Also there are an effect which is provided more clear image because of improving the flickering of the existing display board.

• Korean Journal of Remote Sensing
• /
• v.31 no.2
• /
• pp.85-99
• /
• 2015

TDI CCD sensors are being used for most of the electro-optical camera mounted on the low earth orbit satellite to meet high performance requirements such as SNR and MTF. However, the CMOS sensors which have a lot of implementation advantages over the CCD, are being upgraded to have the TDI function. A few methods for improving the issue of motion blur which is apparent in the CMOS sensor than the CCD sensor, are being introduced. Each pixel can be divided into a few sub-pixels to be read more than once as is the same case with three or four phased CCDs. The fill factor can be reduced intentionally or even a kind of mask can also be implemented at the edge of pixels to reduce the blur. The motion blur can also be reduced in the TDI CMOS sensor by reducing the integration time from the full line scan time. Because the integration time can be controlled easily by the versatile control electronics, one of two performance parameters, MTF and SNR, can be concentrated dynamically depending on the aim of target imaging. MATLAB simulation has been performed and the results are presented in this paper. The goal of the simulation is to compare dynamic MTFs affected by the different methods for reducing the motion blur in the TDI CMOS sensor.