• 전자공학회논문지S
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• 제34S권9호
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• pp.109-117
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• 1997

A new relaxation algorithm based on distribution of matched errors and possibility is proposed to solve efficiently correspondence problem. This algorithm can be applied to various method, such as BMA, feature-, and region-based matching methods, by modifying its smoothness function. It consists of two stages which are transformation and iteration process. In transformation stage, the errors obtained by any matching algorithm are transformed to possibility values according to these statistical distribution. Each grade of possility is updated by some constraints which are defined as smoothness, uniqueness, and discontinuity factor in iteration stage. The discontinuity factor is used to reserve discontinuity of disparity. In conventional methods, it is difficult to find proper weights and stop condition, because only two factors, smoothness and uniqueness, have been used. However, in the proposed mthod, the more smoothing is not ocurred because of discontinuity factor. And it is efective to the various image, even if the image has a severe noise and repeating patterns. In addition, it is shown that the convergence rate and the quality of output are improved.

• 정보처리학회논문지B
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• 제8B권3호
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• pp.311-318
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• 2001

본 논문에서는 중첩되는 영상사이의 평면 투영 변환을 구하는 방법을 제안하였다. 제안한 방법은 정규상관과 직사각형-사변형 평면 투영 변환에 기반 한다. 블록 정합을 이용하여 전역 이동을 계산하고, 중첩되는 영역의 정규 상관 계수 값을 최대로 하는 4개의 대응점을 찾기 위하여 가우시안 영상 피라미드에서 SA(simulated annealing) 알고리즘을 사용하였다. 이들 대응점에서 직사각형-사변형으로의 사상을 이용하여 평면 투영 변환을 계산하고, 마지막으로 중첩되는 영역의 RGB 컬러 값을 선형 가중치에 의해 혼합하였다. 실험으로 세 장의 영상을 한 장읠 큰 모자익 영상으로 합성하는 결과를 보였다.

• 센서학회지
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• 제11권4호
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• pp.239-246
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• 2002

In this paper a new design of multi-layer perceptron(MLP) for camera calibration is proposed. Most existing techniques determine a transformation from 3D spatial points to their image points and camera parameters are tried to be estimated from the transformation. The technique proposed here, on the other hand, determines rays of sight uniquely from image points and parameters are estimated from the relationship using an MLP. By this approach projection and back-projection can be done more straightforwardly. Being based on a geometric model, a network design process becomes less ambiguous, which is a clear merit compared to other neural net based techniques. An MLP designed according to the technique proposed showed fast and stable learning in tests under various conditions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.521-525
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• 2002

In this paper, a computer-vision based pipe-inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplace operator with input image, which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation for line detection. The dimension of inner and outer radius of pipe is calculated by proposed line-scanning method. The method scans several lines along the X and Y axes, calculating the eccentricity of inner and outer circle, by which pipes with wrong end-shape can be classified removed.

• 한국측량학회지
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• 제5권2호
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• pp.47-55
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• 1987

본 연구에서는 내부표정요소와 외부표정 요소를 모두 미지수로 취급하는 직접선형변환의 기본식을 유도하여 비반복적으로 직접 후방교회를 실시할 수 있는 알고리즘을 개발 전산화 하였으며, 기존의 입체도화기와 Digitizer를 이용하여 상좌표를 측정하였다. 입체도화기와 Digitizer를 이용한 상좌표 측정 및 직접선형변환의 타당성을 입증하기 위하여 양해석법으로 자료추출을 실시하였으며, 절대좌표에 대한 표준오차를 분석하였다.

• International Journal of Internet, Broadcasting and Communication
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• 제11권3호
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• pp.1-7
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• 2019

Previously, parallel computing was mainly used in areas requiring high computing performance, but nowadays, multicore CPUs and GPUs have become widespread, and parallel programming advantages can be obtained even in a PC environment. Various parallel programming frameworks using multicore CPUs such as OpenMP and PPL have been announced. Nvidia and AMD have developed parallel programming platforms and APIs for program developers to take advantage of multicore GPUs on their graphics cards. In this paper, we develop digital image transformation programs that runs on each of the major parallel programming frameworks, and measure the execution time. We analyze the characteristics of each framework through the execution time comparison. Also a constant K indicating the ratio of program execution time between different parallel computing environments is presented. Using this, it is possible to predict rough execution time without implementing a parallel program.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 제13회 신호처리 합동 학술대회 논문집
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• pp.299-302
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• 2000

최근에 새로운 텍스트 압축방법인 BWT(Burrows and Wheeler transformation)가 소개되었다. 이 변환은 우수한 텍스트 압축성능을 가지지만 텍스트와 영상의 다른 성질로 인해 영상에 직접 적용될 때 그다지 우수한 압축성능을 기대할 수 없다. 본 논문에서는L-SSKF(Lossless Symmetric Short Kernel Filter)를 사용하여 영상을 대역분할한 후에 BWT를 수행하여 무손실이면서 우수한 압축성능을 가지는 무손실 영상압축방법을 제안한다. 또한 압축성능의 향상을 위해 두과정의 중간에 화소예측방법인GAP(Gradient Adjusted Prediction)를 적용하여 성능개선을 비교하였다.

• Journal of Information Processing Systems
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• 제14권5호
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• pp.1293-1300
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• 2018

For the disadvantages of multi-scale geometric analysis methods such as loss of definition and complex selection of rules in image fusion, an improved multi-focus image fusion method is proposed. First, the initial fused image is quickly obtained based on the lifting stationary wavelet transform, and a simple normalized cut is performed on the initial fused image to obtain different segmented regions. Then, the original image is subjected to NSCT transformation and the absolute value of the high frequency component coefficient in each segmented region is calculated. At last, the region with the largest absolute value is selected as the postfusion region, and the fused multi-focus image is obtained by traversing each segment region. Numerical experiments show that the proposed algorithm can not only simplify the selection of fusion rules, but also overcome loss of definition and has validity.

• 충청수학회지
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• 제25권2호
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• pp.367-377
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• 2012

The goal of the image restoration is to find a good approximation of the original image for the degraded image, the blurring matrix, and the statistics of the noise vector given. Fast truncated Lagrange (FTL) method has been proposed by G. Landi as a image restoration method for large-scale ill-conditioned BTTB linear systems([3]). We implemented FTL method for the image restoration problem with reflective boundary condition which gives better reconstructions of the unknown, the true image.

• 한국멀티미디어학회논문지
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• 제25권5호
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• pp.670-675
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• 2022

This study proposes an improved binarization method to improve image recognition rate. The research goal is to minimize the information loss that occurs during the binarization process, and to transform the object of the original image that cannot be determined through the transformation process into an image that can be judged. The proposed method uses a stepwise segmentation method of an image and divides blocks using prime numbers. Also, within one block, a trapezoidal type of fuzzy is applied. The fuzzy trapezoid is binarized by dividing the brightness histogram area into three parts according to the degree of membership. As a result of the experiment, information loss was minimized in general images. In addition, it was found that the converted binarized image expressed the object better than the original image in the special image in which the brightness region was tilted to one side.