• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12C
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• pp.1138-1146
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• 2009

Digital cameras adopting a single CCD detector collect image color by subsampling in three color planes and successively interpolating the information to reconstruct full-resolution color images. Therefore, to recovery of a full-resolution color image from a color filter array (CFA) like the Bayer pattern is generally considered as an interpolation issue for the unknown color components. In this paper, we first calculate luminance component value by combining R, G, B channel component information which is quite different from the conventional demosaicing algorithm. Because conventional system calculates G channel component followed by computing R and B channel components. Integrating the obtained gradient edge information and the improved weighting function in luminance component, a new edge sensitive demosaicing technique is presented. Based on 24 well known testing images, simulation results proved that our presented high-quality demosaicing technique shows the best image quality performance when compared with several recently presented techniques.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.2
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• pp.85-91
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• 2017

Lenses have different refractive indices for different wavelengths of light. This is why different wavelengths of rays are focused at different positions in the focal plane. Images are blurred and noticeable colored edges appear around the objects, which is known as chromatic aberration (CA). In this paper, an algorithm for removing CA artifacts in color images is proposed. Based on the fact that the gradients of color channels are highly correlated, the differences of the gradients of the channels in edges are minimized. The cost function is designed by using the gradients of the channels. Experimental results show the good performance of the proposed algorithm in removing the CA artifacts.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3154-3156
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• 2000

본 논문에서는 HSV 공간에서의 색상 히스토그램을 이용하여 분할을 수행하여 얻어진 색상 정보와 영상의 에지를 추출한 후 각각의 에지 포인트에 대한 기울기를 히스토그램으로 만들어서 얻어지는 형태 정보를 이용하여 색상 영상 데이터베이스 상에서 영상 검색을 수행할 수 있는 방법을 제시한다. 트레이드마크 영상 데이터베이스에 대해 영상 검색을 수행하여 기존의 영상 검색 방법과의 비교를 통하여 제안한 방법의 우수함을 보이고 일반 영상 데이터베이스의 검색에도 우수하게 적용 가능함을 제시하고자 한다.

• Journal of Navigation and Port Research
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• v.28 no.3
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• pp.233-238
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• 2004

Comer point is a very important information to a pattern recognition of image processing. And so, many researchers develope various detecting comer point algoritms. But, there are some problems to get comer points by 8 directional chain code when the degree of edge line is not integer multiplication of 45 degree. So, we propose a new algorithm which is combined with morphology and human visual conception for optimal comer points without the above defects. We get a good simulation result by this proposed algorithm Ana so, we think this algorithm is very useful to FA(factory automation} and ship's radar system to know some coastal area from its image.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.15-18
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• 2003

본 논문에서는 오손된 EPDM 배전용 현수애자에서 측정한 누설 전류의 파형을 분석하여 정확한 섬락 시기를 예측하기 위한 방법을 제안하였다. 이를 위하여 일정 시간 단위로 측정한 누설 전류들을 포락 한 후 레벨 교차율을 적용해 cdf 형태로 변환하였다. 획득된 cdf들은 서로 다른 기울기(각도)를 가지므로 애자의 섬락 시기를 예측하는데 유용하게 사용될 수 있다. 그러나 cdf들 간의 기울기 차는 매우 작아서 서로 구분되기 어려우므로 이를 해결하기 위하여 새로운 가중치를 정의하여 사용하였다. 실험 결과 제안한 방법은 배전용 현수애자의 섬락 시기를 적절히 예측할 수 있었다.

• The KIPS Transactions:PartB
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• v.17B no.4
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• pp.303-308
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• 2010

In this paper, we propose a medical image registration technique combining the gradient vector flow and modified conditional entropy. The registration is conducted by the use of a measure based on the entropy of conditional probabilities. To achieve the registration, we first define a modified conditional entropy (MCE) computed from the joint histograms for the area intensities of two given images. In order to combine the spatial information into a traditional registration measure, we use the gradient vector flow field. Then the MCE is computed from the gradient vector flow intensity (GVFI) combining the gradient information and their intensity values of original images. To evaluate the performance of the proposed registration method, we conduct experiments with our method as well as existing method based on the mutual information (MI) criteria. We evaluate the precision of MI- and MCE-based measurements by comparing the registration obtained from MR images and transformed CT images. The experimental results show that the proposed method is faster and more accurate than other optimization methods.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.2 s.5
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• pp.19-28
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• 2004

This paper shows how to compensate the skew from the traffic sign included in the natural image and extract the text. The research deals with the Process related to the array image. Ail the process comprises four steps. In the first fart we Perform the preprocessing and Canny edge extraction for the edge in the natural image. In the second pan we perform preprocessing and postprocessing for Hough Transform in order to extract the skewed angle. In the third part we remove the noise images and the complex lines, and then extract the candidate region using the features of the text. In the last part after performing the local binarization in the extracted candidate region, we demonstrate the text extraction by using the differences of the features which appeared between the tett and the non-text in order to select the unnecessary non-text. After carrying out an experiment with the natural image of 100 Pieces that includes the traffic sign. The research indicates a 82.54 percent extraction of the text and a 79.69 percent accuracy of the extraction, and this improved more accurate text extraction in comparison with the existing works such as the method using RLS(Run Length Smoothing) or Fourier Transform. Also this research shows a 94.5 percent extraction in respect of the extraction on the skewed angle. That improved a 26 percent, compared with the way used only Hough Transform. The research is applied to giving the information of the location regarding the walking aid system for the blind or the operation of a driverless vehicle

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.163-170
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• 2013

In general, images of outdoor scenes often contain degradation due to dust, water drop, haze, fog, smoke and so on, as a result they cause the contrast reduction and color fading. Haze removal is not easier problem due to the inherent ambiguity between the haze and the underlying scene. So, we propose a novel method to solve single scene dehazing problem using the region segmentation based on graph algorithm that has used a gradient value as a cost function. We segment the scene into different regions according to depth-related information and then estimate the global atmospheric light. The medium transmission can be directly estimated by the threshold function of graph-based segmentation algorithm. After estimating the medium transmission, we can restore the haze-free scene. We evaluated the degree of the visibility restoration between the proposed method and the existing methods by calculating the gradient of the edge between the restored scene and the original scene. Results on a variety of outdoor haze scene demonstrated the powerful haze removal and enhanced image quality of the proposed method.

• The KIPS Transactions:PartB
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• v.18B no.3
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• pp.131-138
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• 2011

In this paper, we compare our proposed method with previous methods for the volumetric image segmentation using level set. In order to obtain an exact segmentation, the region and boundary information of image object are used in our proposed speed function. The boundary information is defined by the gradient vector flow obtained from the gradient images and the region information is defined by Gaussian distribution information of pixel intensity in a region-of-interest for image segmentation. Also the regular term is used to remove the noise around surface. We show various experimental results of real medical volume images to verify the superiority of proposed method.

• The KIPS Transactions:PartB
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• v.8B no.6
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• pp.705-717
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• 2001

In this paper, we propose a rapid lane detection method to extract a preceding vehicle from sequential images captured by a single monocular CCD camera. We detect positions of lanes for an individual image within the limited area that would not be hidden and thereby compute the slopes of the detected lanes. Then we find a search area where vehicles would exist and extract the position of the preceding vehicle within the area with edge component by applying a structured method. To verify the effects of the proposed method, we capture the road images with a notebook PC and a CCD camera for PC and present the results such as processing time for lane detection, accuracy and vehicles detection against the images.