• 대한원격탐사학회지
• /
• 제38권6_1호
• /
• pp.1257-1271
• /
• 2022

최근 많은 수의 지구관측용 광학위성이 개발되어 위성영상에 대한 수요가 증가하고 있다. 따라서, 위성영상의 활발한 활용을 위해서 신속한 전처리 과정이 요구된다. 위성영상 정합은 두 영상을 하나의 특정한 좌표계로 변환하여 등록하는 기술로서 원격탐사 분야에서 영상정합 기술은 서로 다른 대역의 영상을 정렬하거나, 두 위성영상 간의 상대적인 위치 오차를 수정하는데 사용된다. 본 논문에서는 서로 다른 Ground Sample Distance (GSD)를 가지는 위성영상 간의 자동 영상정합 방법을 제안하였다. 제안방법은 개선된 특징점 매칭방법과 강인한 변환모델 추정기법을 기반으로 하며, 다음과 같이 5가지 처리과정으로 구성된다: 중첩 영역 계산, 개선된 특징점 탐지, 특징점 매칭, 강인한 변환모델 추정, 영상 리샘플링. 특징점 탐지를 위해서 중첩영역을 추출하여 두 영상의 GSD가 유사하도록 영상 리샘플링을 수행하였다. 특징점 매칭 단계에서는, Oriented FAST and Rotated BRIEF (ORB) 알고리즘을 사용하여 영상정합 성능을 향상시켰다. 영상정합 실험은 KOMPSAT-3A와 RapidEye영상을 실험대상으로 수행되었으며 제안방법의 성능검증은 정성적, 정량적 두 가지 방법으로 수행되었다. 영상정합의 재투영오차는 RapidEye GSD를 기준으로 1.277 (8.3 m)에서 1.608 (10.452 m)의 픽셀 정확도를 보였다. 즉, 결론적으로, 제안방법을 통해 이종해상도 위성영상의 영상정합 가능성을 확인하였다.

• 산업경영시스템학회지
• /
• 제27권3호
• /
• pp.59-65
• /
• 2004

This paper explores an image segmentation and representation method using Vector Quantization(VQ) on color and texture for content-based image retrieval system. The basic idea is a transformation from the raw pixel data to a small set of image regions which are coherent in color and texture space. These schemes are used for object-based image retrieval. Features for image retrieval are three color features from HSV color model and five texture features from Gray-level co-occurrence matrices. Once the feature extraction scheme is performed in the image, 8-dimensional feature vectors represent each pixel in the image. VQ algorithm is used to cluster each pixel data into groups. A representative feature table based on the dominant groups is obtained and used to retrieve similar images according to object within the image. The proposed method can retrieve similar images even in the case that the objects are translated, scaled, and rotated.

• 한국항해학회지
• /
• 제13권1호
• /
• pp.11-20
• /
• 1989

Radar image data were collected through the on-line data acquisition system of A/D converter and personal computer, and the image was restorated on CRT or plotter after digital image processing of the data. The digital image processing system which was developed for this study, consisted of some kinds of software as follows : rearrangement, transformation, and enhancement of the image data in real space or frequency space by Fourier transform, edge detection of the image, compact processing, state inferential processing, and so on. Since the image of PPI radar sweeps from the center to the circumference of a circle, the image within a given period has the shape of fan. Therefore the acquired data were transformed to have the same interval as that of data in outmost concentricity. The results of various image processing methods using transformed data were better than those of the methods using original data.

• 한국측량학회지
• /
• 제27권1호
• /
• pp.667-675
• /
• 2009

영상정합은 원격 탐사, GIS 등과 같은 영상 활용 분야에서 매우 광범위하게 적용된다. 일반적으로 초기의 정합점 데이터들은 영상정합의 정확도를 떨어뜨리는 오정합을 포함하고 있다. 본 논문의 목적은 영상정합에서 정확도를 유지하기 위해 오정합의 탐색 및 제거를 위한 강건한 접근법을 개발하는 것이다. 본 논문은 자동으로 오정합을 탐색하기 위해 역방향 정합 유사변환, RANSAC 알고리즘을 사용하였으며 빠르고 효율적인 영상정합을 위해 중복영역의 계산, 블록기반 처리 등과 같은 전처리 단계를 사용하였다. 논문에서 제안한 방법을 실제 항공사진 영상쌍에 적용하여 robustness와 효율성 측면에서 그 결과를 분석하였다.

• 한국정밀공학회지
• /
• 제21권12호
• /
• pp.84-91
• /
• 2004

A CCD camera with a laser stripe was applied to realize the automatic weld seam tracking in GMAW. It takes relatively long time to process image on-line control using the basic Hough transformation, but it has a tendency of robustness over the noises such as spatter and arc tight. For this reason, it was complemented with adaptive Hough transformation to have an on-line processing ability for scanning specific weld points. The adaptive Hough transformation was used to extract laser stripes and to obtain specific weld points. The 3-dimensional information obtained from the vision system made it possible to generate the weld torch path and to obtain the information such as width and depth of weld line. In this study, a neural network based on the generalized delta rule algorithm was adapted for the process control of GMA, such as welding speed, arc voltage and wire feeding speed.

• Journal of Welding and Joining
• /
• 제19권6호
• /
• pp.600-607
• /
• 2001

A CCD camera with a laser stripe was applied to realize the automatic weld seam tracking in GMAW. It takes relatively long time to process image on-line control using the basic Hough transformation, but it has a tendency of robustness over the noises such as spatter and arc light. For this reason. it was complemented with adaptive Hough transformation to have an on-line processing ability for scanning specific weld points. The adaptive Hough transformation was used to extract laser stripes and to obtain specific weld points. The 3-dimensional information obtained from the vision system made it possible to generate the weld torch path and to obtain the information such as width and depth of weld line. We controled the wire feeding rate using informations of weld line.

• 대한수학회보
• /
• 제56권3호
• /
• pp.681-689
• /
• 2019

The $M{\ddot{o}}bius$ homogeneous submanifold in ${\mathbb{S}}^{n+1}$ is an orbit of a subgroup of the $M{\ddot{o}}bius$ transformation group of ${\mathbb{S}}^{n+1}$. In this note, We prove that a compact $M{\ddot{o}}bius$ homogeneous submanifold in ${\mathbb{S}}^{n+1}$ is the image of a $M{\ddot{o}}bius$ transformation of the isometric homogeneous submanifold in ${\mathbb{S}}^{n+1}$.

• 한국농촌건축학회논문집
• /
• 제14권1호
• /
• pp.99-106
• /
• 2012

Transformation which is the major damage factor of living space in folk village is caused by improvement behaviors reflecting real requirements of residents who are the subjects of life. Such a process changes traditional space structure gradually and lowers preservative value of folk village. Therefore this study examines transformational conditions of living space centering around changes of spatial components and plane forms through literature and field research and analyzes characteristics of transformational phenomenon. This study examined changes of components and transformation of Seongeup folk village. While main room plane was diversified by residents' requirements, it was not harmonized with traditional image of Seongeup folk village. Transformation of living space at Seongeup Folk Village was positive from the side of residents' living requirements, but negative in that it damaged unique identity of folk village. Accordingly, it is thought that deliberation considering residents' living requirements as the field of their life with maintenance of original form for the purpose of preserving folk village and professionals' support and legal study for revision of approval system are continuously required.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
• /
• pp.358-360
• /
• 2004

The digital images contain a significant amount of redundancy and require a large amount of data for their storage and transmission. Therefore, the image compression is necessary to treat digital images efficiently. The goal of image compression is to reduce the number of bits required for their representation. The image compression can reduce the size of image data using contractive mapping of original image. Among the compression methods, the mapping is affine transformation to find the block(called range block) which is the most similar to the original image. In this paper, we applied the neural network(SOM) in encoding. In order to improve the performance of image compression, we intend to reduce the similarities and unnecesaries comparing with the originals in the codebook. In standard image coding, the affine transform is performed with eight isometries that used to approximate domain blocks to range blocks.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제14권12호
• /
• pp.4835-4848
• /
• 2020

The recent expansion of the digital content market is increasing the technical demand for various facial image transformations within the virtual environment. The recent image translation technology enables changes between various domains. However, current image-to-image translation techniques do not provide stable performance through unsupervised learning, especially for shape learning in the face transition field. This is because the face is a highly sensitive feature, and the quality of the resulting image is significantly affected, especially if the transitions in the eyes, nose, and mouth are not effectively performed. We herein propose a new unsupervised method that can transform an in-wild face image into another face style through radical transformation. Specifically, the proposed method applies two face-specific feature loss functions for a generative adversarial network. The proposed technique shows that stable domain conversion to other domains is possible while maintaining the image characteristics in the eyes, nose, and mouth.