• Korean Journal of Remote Sensing
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• v.21 no.6
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• pp.483-491
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• 2005

SAR signal processing technique has been considered a crucial technical part in order to generate an image from radar signal data and ADD (Agency for Defense Development) has focused on this area for years to develope our own SAR Processor for various SAR systems (Radarsat, ERS, KOMSAR). In this paper, we investigated major techniques related to generation of SAR images and developed ASPR (ADD SAR Processor for Radarsat) practically using the commercial Radarsat-1 radar signal data (RAW). We demonstrated the performance of the ASPR in comparison with the image generated by MDA and Vexcel's SAR Processor (FOCUS).

• Journal of the Korea Society of Computer and Information
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• v.6 no.3
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• pp.11-16
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• 2001

This paper propose the methods for input systems which can save video inputs from multic in PC environment. For 3-D display the input data from 4 channels are sequentially disp turn with the speed of 4 times faster than one channels. The system consists of 4 cameras, monitor for monitoring the input process. an input processor, and a monitor which can dis data with the speed of 120f㎰. This paper also discusses the operation of the system and st requirements of the system. The circuit of the proposed system is verified using PSpice simulation.

• Journal of the Institute of Convergence Signal Processing
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• v.18 no.2
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• pp.76-83
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• 2017

In this study, the original medical image, DICOM file, was converted into TIFF, BITMAP, GIF, JPEG image file, and then the conversion loss ratio according to the image compression and conversion process was quantitatively evaluated using Origin pro and ICY image analysis program. As the evaluation method, 50% MTF, structural similarity index, MSE, RMSE, maximum signal - to - noise ratio and so on were evaluated. The TIFF image file showed the same result as DICOM image in all experimental groups, Image file format. In this study, we propose a new method for evaluating the quality of digital images by applying original evaluation program such as Origin pro or ICY medical image analysis program. Is expected to be used as research data in the field of medical image processing, and TIFF image file showing the same result as DICOM image in the basic research field using digital medical image and evaluation program that does not support DICOM file Therefore, it is believed that it will help to secure reliability in digital medical image processing research using image file.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.847-849
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• 2001

방대한 양의 실시간 연산을 요구하는 영상 신호처리, 소나, 레이다와 같은 시스템에서는 성능을 최대화하기 위해 병렬 신호처리 시스템의 사용이 불가피하다. 본 논문은 2개의 DSP칩(TMS320C6701)을 사용하여 설계 및 구현한 병렬 신호처리보드의 구성과 이를 구동시키기 위한 소프트웨어 구성체계를 제시한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1C
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• pp.36-45
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• 2006

In this paper, multiview calibration system for an effective 3D display is proposed. This system can be obtain 4-view image from multiview camera system. Also it can be rectify lens and camera distortion, error of bright and color, and it can be calibrate distortion of geometry. In this paper, we proposed the signal processing skill to calibrate the camera distortions which are able to take place from the acquisited multiview images. The discordance of the brightness and the colors are calibrated the color transform by extracting the feature point, correspondence point. And the difference of brightness is calibrated by using the differential map of brightness from each camera image. A spherical lens distortion is corrected by extracting the pattern of the multiview camera images. Finally the camera error and size among the multiview cameras is calibrated by removing the distortion. Accordingly, this proposed rectification & calibration system enable to effective 3D display and acquire natural multiview 3D image.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.4
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• pp.128-134
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• 2014

In this paper, we propose a detection method of the leukocyte motions in a microvessel by using spatiotemporal image analysis. The leukocyte motions that adhere to blood vessel walls can be visualized to move along the blood vessel wall's contours in a sequence of images. In this proposal method, we use the constraint that the leukocytes move along the blood vessel wall's contours and detect the leukocyte motions by using the spatiotemporal image analysis method. The generated spatiotemporal image is processed by a special-purpose orientation-selective filter and then subsequent grouping processes are done. The subsequent grouping processes select and group the leukocyte trace segments among all the segments obtained by simple thresholding and skeletonizing operations. Experimental results show that the proposed method can stably detect the leukocyte motions even when multiple leukocyte traces intersect each other.

• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.107-113
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• 1999

The purpose of this study was to develop a miniature imaging gamma probe with high performance that can detect small or residual tumors after surgery. Gamma probe detector system consists of NaI(Tl) scintillator, position sensitive photomultiplier tube (PSPMT), and collimator. PSPMT was optically coupled with 6.5 mm thick, 7.62 cm diameter of NaI(Tl) crystal and supplied with -1000V for high voltage. Parallel hexagonal hole collimator was manufactured for characteristics of 40-mm hole length, 1.3-mm hole diameter, and 0.22 mm septal thickness. Electronics consist of position and trigger signal readout systems. Position signals were obtained with summing, subtracting, and dividing circuit using preamplifer and amplifier. Trigger signals were obtained using summing amplifier, constant fraction discriminator, and gate and delay generator module with preamplifer. Data acquisition and processing were performed by Gamma-PF interface board inserted into pentium PC and PIP software. For imaging studies, flood and slit mask images were acquired using a point source. Two hole phantom images were also acquired with collimator. Intrinsic and system spatial resolutions were measured as 3.97 mm and 5.97 mm, respectively. In conclusion, Miniature gamma probe images based on the PSPMT showed good image quality, we conclude that the miniature imaging gamma probe was successfully developed and good image data were obtained. However, further studies will be required to optimize imaging characteristics.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11a
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• pp.735-738
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• 2002

휘도 신호만을 이용한 흑백 TV 에서부터 오늘날의 디지털 HDTV 에 이르기까지의 TV 시스템에서 사용되어 온 영상 신호의 생성, 전송 및 재생 방법은 HDTV, 디지털 시네마 등 영상 시스템의 획기적인 발전과 더불어, 보다 고선명, 고화질을 요구하게 되었다. 본 논문에서는 기존의 TV 시스템에서의 영상재생 결과와, constant luminance방법에 의한 영상 재생 결과를 관찰자 평가 실험을 통해 비교 분석한 데이터를 제시한다.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.42-45
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• 2003

일반적으로 영상내의 중요한 정보는 객체 영역에 많이 포함되어 있다. 객체 영역 우선 전송 방법은 영상의 전 영역에 대해 동일한 중요도로 전송하는 일반적인 점진적 부호화 방법과는 달리 객체 영역만을 우선적으로 부호화 하여 전송하기 때문에 짧은 시간 내에 원 영상을 보다 빨리 파악할 수 있다. 따라서 본 논문에서는 양방향 반올림 필터를 이용한 MRWD기반 객체 영역 우선 전송 기법을 제안한다. 제안한 방법은 양방향 반올림 필터에 의해 객체 영역을 추출한 후, MRWD를 이용하여 부호화를 수행하므로, 객체 영역의 웨이브릿 계수들을 우선 전송함으로써 매우 낮은 비트율에서 영상내의 중요 정보를 파악할 수 있다. 따라서, 인터넷상에서 사용자가 영상을 검색할 경우 보다 빨리 원하는 정보를 파악할 수 있어 검색 시간과 검색 효율을 개선시킬 수 있다.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.249-252
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• 2000

본 논문에서는 MPEG으로 압축된 영상에 대해서 급격한 장면 변화에 의한 shot 경계(cut)와 점진적 장면 변화에 의한 shot 경계(dissolve)를 검출하여 비디오 shot을 분할하는 기법을 제안한다. 기존의 방법으로 잘 검출하지 못하였던 점진적 장면 변화에 의한 shot의 경계를 검출하기 위한 기법을 제안한다. 먼저 압축영역의 기법 중 DCT DC 값을 비교하는 방법을 이용하여 cut에 의한 shot 경계를 검출한다 그리고 움직임 벡터(MV)의 비를 비교하는 방법을 사용하여 dissolve에 의한 shot 경계의 후보지들을 얻어내고, 선택된 후보지들 중 n번째와 n＋2번째 후보지 영상으로 dissolve 영상을 만들어 n＋1번째 후보지의 영상과 유사도를 비교하여 dissolve를 검출한다. 이와 같이 압축영역에서 cut에 의한 shot 경계와 dissolve에 의한 shot 경계의 후보지를 검출해 내고, 검출된 shot 경계 후보지들에서 dissolve에 의한 shot 경계를 검출하는 방법을 함으로서 MPEG 비디오 영상의 복원량을 최소화하여 수행 속도를 높이면서도 cut과 dissolve 두 가지 모두를 효과적으로 검출할 수 있었다.