• Spatial Information Research
• /
• v.13 no.1 s.32
• /
• pp.55-63
• /
• 2005

Direct Georeferencing(DG) Is based on the direct measurement of the projection centers and rotation angle of sensor through loading the GPS and INS in aircraft. The methods can offer us to acquire the exterior orientation parameters with only minimum GCPs, even the ground control process could be completely skipped. Hence, as long as securing Digital Elevation Model (DEM), it is feasible to generate digital orthophotos without performing the aerial triangulation with Ground Control Point (GCP) surveying. In this study, the DEM is automatically generated by using a image matching technique based on aerial photos and exterior orientation parameters. This is followed by producing an orthophoto from these results. Finally, accuracy analysis of the georeferencing technique for generating orthoimage indicates that RMS errors of 62cm and 76cm occurred at the X and the Y axis, respectively. This means that the results fulfill the demanding accuracy of the 1:5000 digital map. Hence, it is possible to conclude from this study that the direct georeferencing based orthoimage generation method is able to effectively digital map update.

• Journal of Korean Society for Geospatial Information Science
• /
• v.10 no.3 s.21
• /
• pp.17-27
• /
• 2002

It is desirable to use a photogrammetric scanner to minimize the errors from the scanning procedure in case of building aerial photo image DB. The photogrammetric scanner, however, is highly expensive to have only limited number of scanners available, therefore the general-purpose scanners have been considered as an alternative. This study has mainly been focused to see the possibility of the general-purpose scanner to be used for scanning aerial photographs. For that, the analysis of the image coordinates were made as well as the accuracy evaluation of each phase. In addition to that, as the application of the orthophoto images has been increased, the magnitudes of the errors from the DEM generation and orthophoto projection were analyzed. Also, the calibration program was developed to verify the geometric distortion of the automatic scanner to contribute to enhance the quality of the aerial photo image DB.

• Journal of KIISE:Computer Systems and Theory
• /
• v.31 no.1_2
• /
• pp.10-18
• /
• 2004

Quadtree, which is a hierarchical data structure, is a very important data structure to represent binary images. The linear quadtree representation as a way to store a quadtree is efficient to save space compared with other representations. Therefore, it has been widely studied to develop efficient algorithms to execute operations related with quadtrees. The operations of unaligned linear quadtrees, which are operations among the linear quadtrees with different origin, are able to perform the translated or rotated images efficiently. And this operations requires alignment of the linear quadtrees. In this paper, we present an efficient algorithm to perform alignment of unaligned linear quadtrees, using three-dimensional $n{\pm}n{\pm}n$ processors on RMESH(Reconfigurable MESH). This algorithm has constant-time complexity by using efficient basic operations to route the locational codes of quardtree on the hierarchical structure of $n{\pm}n{\pm}n$ RMESH.

• Journal of the Korea Computer Graphics Society
• /
• v.14 no.3
• /
• pp.1-9
• /
• 2008

This paper presents a novel optimization-based saliency-preserving method for converting color images to grayscale in a manner consistent with conventional approaches of black-and-white photographers. In black-and-white photography, a colored filter called a contrast filter has been commonly employed on a camera to lighten or darken selected colors. In addition, local exposure controls such as dodging and burning techniques are typically employed in the darkroom process to change the exposure of local areas within the print without affecting the overall exposure. Our method seeks a digital version of a conventional contrast filter to preserve visually-important image features. Furthermore, conventional burning and dodging techniques are addressed, together with image similarity weights, to give edge-aware local exposure control over the image space. Our method can be efficiently optimized on GPU. According to the experiments, CUDA implementation enables 1 megapixel color images to be converted to grayscale at interactive frames rates.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.21 no.1
• /
• pp.27-36
• /
• 2003

Generally, the latest acquisition method of geo-spatial informations in urban area is executed by generation of digital elevation model (DEM) and digital ortho image by digital photogrammetry method which is used large scale photo image. However, the biggest problem of this method is coarse accuracy of DEM which is automatically generated by digital photogrammetry workstation system. The coarse accuracy of DEM caused geo-spatial information in urban area to reduce of accuracy. Therefore, this study is purposed to increase of DEM accuracy which is applied to method terrain classification in urban area. As the results of this study, the proposed method of this study which is increased to accuracy of DEM by classification of terrain is better than accuracy of DEM which is automatically generated by digital photogrammetry workstaion system. And, the edge detection method which is proposed by this study is established to capability of 3D digital mapping in urban area.

• Journal of the Korea Society of Computer and Information
• /
• v.18 no.4
• /
• pp.13-18
• /
• 2013

Panorama picturing is an elongated photographing technique that connects images with rotating and moving multiple images horizontally that are partly overlapped. However, for hand-operated photographs, it is difficult to adjust overlapped parts because of tilted angles. There has been a study comparing adjacent pictures using labeling technique but it was time-consuming and had angle dissonant cases in nature. In this paper, we propose a less time-consuming paranoiac scene reconstruction method. Our method is also based on labeling-and-comparing technique but uses only 1/3 of it. Then, if there exists angle dissonance, it tries to find characteristic points by SURF algorithm and adjusts them with homography. The efficacy of this method is experimentally verified by experiments using various images

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.26 no.2
• /
• pp.103-110
• /
• 2008

General lens, widely using in Photogrammetry, has narrow view, and have to adjust "Image-Registration Method" after obtain images and it need cost; economic, period of time. Recent days, there is various study that use wide-angle lens, usually for robotics field, put to practical use in photogrammetry instead of general lens. In this studies, distortion tendency of wide-angle lens and utilize the correction techniques suitable to wide-angle lens by the existing photographic survey methods. After carrying out the calibration of the wide-angle lens, we calculated the correction parameters, and then developed the method that convert the original image-point to new image-point correcting distortion. For authorization the developed algorithm, we had inspection about shape and position; there are approximately 2D RMSE of 3 pixel, cx = 2, and cy = 3 different.

• Journal of Veterinary Clinics
• /
• v.30 no.5
• /
• pp.390-393
• /
• 2013

This case study describes the imaging features of radiography and computed tomography (CT) in four small breed dogs with lung lobe torsion. The medical records, thoracic radiographs and CT images of four dogs with confirmed lung lobe torsion were retrospectively reviewed. Pleural effusion and increased lobar opacity/density were seen on all CT and thoracic radiography in all four dogs. CT revealed narrowed/collapsed bronchus in all four dogs, while this was only appreciated on one thoracic radiography. The vesicular emphysema pattern was seen on four CT but only on three radiographic examinations. The specific findings of lung lobe torsion were vesicular emphysema and a narrowed/collapsed bronchus. These findings were more easily recognized on CT than with thoracic radiographs.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2004.11a
• /
• pp.153-159
• /
• 2004

Recently remote sensing technology is applied for digital and photographical data acquisition by use of satellites sensors. And It used for images restoration of vanished spatial information at the same sites according to changed of time and spaces. In this study, it applied for the 3-dimensional images generation and fly simulation to possibility for various application. As a results of its applied, it gained the results not only improvement of present methods but also real various application possibilities for 3 dimensional Image restoration.

• The Optical Journal
• /
• s.145
• /
• pp.41-44
• /
• 2013

지난 4월 4일부터 7일까지 나흘간 열린 '2013 서울국제사진영상기자재전(PHOTO&IMAGING 2013)'이 역대 최다 관람객인 7만 5000여 명을 동원하며 성황리에 막을 내렸다. 한국광학기기산업협회, 코엑스, 한국사진영상기재협회 주최로 삼성 코엑스 본관 1층 A, B홀에서 열린 이번 행사에는 삼성, 캐논, 니콘, 세기P&C, 한국후지필름 등 21개 나라에서 197개 업체가 748부스 규모로 참가해 촬영부터 인화까지 영진 영상에 관한 다양한 제품, 콘텐츠 등을 선보였다.