• 전자공학회논문지B
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• 제31B권7호
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• pp.9-15
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• 1994

This paper proposes a image compression algorithm which stores and transmites image data efficiently. The proposed compression algorithm modify enhances compression rate by modified ZIG-ZAG Scanning in JPEG standard algorithm which is based on 2D-DCT. And the up-compatible method of proposed algorithm can solve compatible problem with JPEG that is cased by modified ZIG-ZAG Scanning. And this paper presentes a block diagram of hardware for real-time processing.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제15권2호
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• pp.121-125
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• 2015

In this paper, we propose a method that extracts features from character patterns using the fractal dimension of chaos theory. The input character pattern image is converted into time-series data. Then, using the modified Henon system suggested in this paper, it determines the last features of the character pattern image after calculating the box-counting dimension, natural measure, information bit, and information (fractal) dimension. Finally, character pattern recognition is performed by statistically finding each information bit that shows the minimum difference compared with a normalized character pattern database.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.239-240
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• 2007

We suggest an image watermarking algorithm. We perform the modified Log-Polar Mapping (LPM) and the DFT/DCT on the original image and embed the watermark. Binary images are used for watermarks. Watermarking strength is adaptively adjusted depend on the mapped data Experimental results show that this method is robust to JPEG and rotation distortions.

• 한국정보전자통신기술학회논문지
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• 제4권3호
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• pp.174-181
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• 2011

본 논문에서는 적외선 위성영상과 광학 위성영상을 위한 정합방법을 제안하였다. 적외선 영상은 물체에서 방사하는 열에너지를 측정한 것으로, 광학 영상과는 다른 정보를 보여주는 장점으로 많은 분야에 응용된다. 하지만 적외선 영상은 대비가 광학 영상에 비해 낮아, 영상 정합을 위한 특징점 추출 및 매칭을 하기가 어렵다. 이를 극복하기 위해, Modifed SIFT(Scale Invariant Feature Transform)를 사용하여 특징점을 추출 및 매칭하였다. 또한 특징점의 상대적 변별력을 증가시키기 위해, 영상을 블록화해서 Modified SIFT와 RANSAC (RANdom SAample Concensus)을 적용하였다. 마지막으로 오매칭이 있는 블록의 특징점을 제거하기 위해, 각 블록에서 추출된 특징점을 원 영상의 좌표계로 통합해 RANSAC을 다시 한 번 적용하였다. 실험에 사용된 적외선 영상의 파장대역은 3~5um이며, 실험결과 제안된 방법은 적외선과 광학 영상정합에 강인한 성능을 보였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2385-2388
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• 2005

In this paper, we propose the estimation method for the image affine information for computer vision. The first estimation method is given based on the XYS image normalization and the second estimation method is based on the image normalization by Pei and Lin. The XYS normalization method turns out to have better performance than the method by Pei and Lin. In addition, we show that rotation and aspect ratio information can be obtained using the central moments of both the original image and the sensed image. Finally, we propose the modified version of the normalization method so that we may control the size of the image.

• 융합신호처리학회논문지
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• 제11권2호
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• pp.104-111
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• 2010

본 논문은 DCT 압축 영역에서 공간 주파수 특성을 이용한 적응 영상향상 방법에 관한 것이다. 영상의 동적범위를 압축하기 위해 Retinex 이론을 이용하여 영상의 조명성분인 dc 계수들을 조절하였으며, 대비를 개선하기 위해 인간의 시각 체계와 계수들의 공간 주파수 특성을 이용하여 ac 계수들을 수정하였다. 세로 방향, 가로 방향, 그리고 혼합된 공간 주파수 성분으로 분류된 ac계수들은 영상향상에 발생하는 블록화 현상을 최소화하기 위하여 적응적으로 수정하였다. 제안된 방법은 영상의 동적 범위 압축과 적응적 대비 개선을 이용하여 기존 방법보다 블록화 현상이 없는 효과적인 영상 향상의 결과를 가져왔다.

• 대한의용생체공학회:의공학회지
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• 제11권1호
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• pp.113-120
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• 1990

In this paper, the deconvolution method utilizing a modified Wiener filter is applied for the enhancement of lateral resolution of ultrasonic B-scan Images. For this purpose, a phantom composed of wires which are 0.6mm of diameter and apart in the range between 3 to 9mm is constructed. The modified Wiener filter with optimal parameter is applied to the phantom for the analysis of ultrasonic image. The results obtained are as follows'When all parameters of the modified Wiener filter are optimal, the resolution of B-scan images is enhanced by 50 percent : Othenrise, the images are blurred, spilt at peak points, or noises are strengthened severely. When the point-spread function representing the characteristic function of the system is determined, the selection ranges of op- timum parameters may be narrowed. It is expected that the proposed method may be able to apply to clinic situations for more accurate image analysis by means of reducing the loss of important information.

• The Journal of the Acoustical Society of Korea
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• 제28권3E호
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• pp.118-135
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• 2009

The level set based approach is one of active methods for contour extraction in image segmentation. Since Osher and Sethian introduced the level set framework in 1988, the method has made the great impact on image segmentation. However, there are some problems to be solved; such as multi-objects segmentation, noise filtering and much calculation amount. In this paper we address the drawbacks of the previous level set methods and propose an extension of the traditional fast level set to cope with the limitations. We introduce a relationship matrix, a new split-and-merge criterion, a modified Chan-Vese criterion and a novel filtering criterion into the traditional fast level set approach. With the segmentation experiments we evaluate the proposed method and show the promising results of the proposed method.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.2076-2079
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• 2003

This paper describes an efficient thresholding method for the binarization of a grey-level letter image. This method determines the adaptive threshold for letter image binarization by introducing the readjusting parameter, based on the global variance of the input image. Experimental results show that the proposed binarization method outperforms on the various letter images with a texture or noise when compared to the other methods.

• 제어로봇시스템학회논문지
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• 제9권10호
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• pp.774-781
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• 2003

The important factors that cause position error in X-Y robot are inertial force, frictions and spring distortion in screw or coupling. We have to estimate these factors precisely to correct position errors, Which is very difficult. In this paper, we makes systems to inspect metal stencil which is used to print solder paste on pads of SMD of PCB with low precision X-Y robot and vision system. To correct position error that is caused by low precision X-Y robot, we defines position error vector that is formed with position of objects that exist in reference and camera image. We apply MHT(Modified Hough Transformation) for the aim of determining the dominant position error vector. We modify reference image using extracted dominant position error vector and obtain reference image that is the same with camera image. Effectiveness and performance of this method are verified by simulation and experiment.