• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.9
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• pp.70-76
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• 1998

By controlling the pixel of a LCD spatial light modulator electronically, we made a real-time moving window passing through the light on a LCD spatial light modulator. By using this LCD moving window, we suggested an angular multiplexed holographic memory system and in case of windows of 10$\times$10 pixels and 2$\times$2 pixels the total numbers of address are 1,536 and 38,400, respectively. To demonstrate the feasibility of the proposed method, we recorded and reconstructed 30 images by 30 input addresses.

• 한국지형공간정보학회:학술대회논문집
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• 1993.10a
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• pp.101-106
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• 1993

본 연구의 목적은 토지자원의 유효한 개발과 관리를 위해 원격탐사 자료 및 지상자료를 이용하여 토지 이용의 예측 모형을 정립하고 실제로 제주도 지역에 적용하여 그 실증을 거치는 것이었다. 본 토형은 계절분석(multi-date processing) 및 다중분석 (multi-file processing)기법을 채택하고 Markov의 확률 이전 계산법 및 판별 함수 (discriminant function) 계산법으로부터 합성 출현된 공간적/시간적 토지이용 투영방법을 채택하였다. 판별 함수 계산법은 토지이용 변화상의 최다 경향치를 산출하기 위해 제주도 경관 평면(landscape plane) 전지역의 각 화소(pixel)에 적용되고, 확률 이전 계산법은 특정 미래 시간 간극상에서 상이한 토지이용으로 변화하는 이들 화소의 수량을 결정한다. 본 합성 모형은 이렇게 토지이용 변화성(정성적)과 그 화소의 수량(정량적)을 결합하여 경관 평면상에서 미래의 토지이용 예측을 가능케하는 것이다.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.77-85
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• 2015

In this paper, we present a new method that can detect forged color region using color pattern decomposition and hypothesis testing approach. On the basis of the fact that the variance of the interpolated pixel is smaller than that of the original pixel, we use a statistical test method to judge the statistical inconsistency of variance. For this, we calculate the variance adopting a color pattern decomposition according to the demosaicking pattern. In addition, we apply high-pass filtering to enlarge the difference between the variances of original and interpolated pixel. Through experimental simulations, we can see that our proposed method can effectively detect forged color regions and shows superior detection performance compared to the conventional method.

• Journal of Digital Contents Society
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• v.9 no.1
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• pp.17-26
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• 2008

This paper has for its object to propose AFOD(Adaptive First-Order Decimator) which sets a value of decimated element as an average of a value of neighbor intelligible component and a output value of FOD(First-Order Decimator) for the target pixel, and to analyze its performance in terms of subjective image quality and hardware complexity. In the proposed AFOD, a target pixel located at the center of sliding window is selected first, then the gradient amplitudes of its right neighbor pixel and its lower neighbor pixel are calculated using first order derivative operator respectively. Secondly, each gradient amplitude is divided by the summation result of two gradient amplitudes to generate each local intelligible weight. Next, a value of neighbor intelligible component is defined by adding a value of the right neighbor pixel times its local intelligible weight to a value of the lower neighbor pixel times its intelligible weight. Since the proposed method adaptively reflects neighbor intelligible informations of neighbor pixels on the decimated element according to each local intelligible weight, it can effectively suppress the blurring effect being the demerit of FOD. It also possesses the advantages that it can keep the merits of FOD with the good results on average but also lower computational cost.

• Korean Journal of Optics and Photonics
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• v.23 no.4
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• pp.147-153
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• 2012

Multi-view 3D displays based on a limited number of pixels have the problem that the stereo-scopic image has a low resolution because of increasing view number. To solve the problem of low resolution, we propose an optical approaching method that focuses the width of a unit pixel by using a commercial spherical shape lenticular lens sheet and increases the effective resolution by increasing the number of sources of light in the multi-view 3D display system based on projection type. The method was performed in such an order that several main derivable parameters were defined, and, through the theoretical and experimental result, the value of the contractible unit pixel width and the scalable effective resolution was derived in a given system environment. As a result, for the case that the ray of light from the projector transmitted the 25 LPI lenticular lens sheet which has the pitch size 1.016 mm, the focused unit pixel width was 0.19 mm and the scalable effective resolution was, at most, 5 times wider than the original one. In addition, the range of depth of focus was 1.496 mm, which shows us the range of thickness tolerances of commercial spherical shape lenticular lens sheet and sufficient optical alignment tolerances.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.1
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• pp.120-127
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• 2010

This paper presents a SR method using adaptive interpolation based on local gradient features to obtain a high quality SR image. In this method, the distance between the interpolated pixel and the neighboring valid pixel is considered by using local gradient properties. The interpolation coefficients take the local gradient of the LR images into account. The smaller the local gradient of a pixel is, the more influence it should have on the interpolated pixel. And the median filter is finally applied to reduce the blurring and noise of the interpolated HR image. Experiment results show the effectiveness of the proposed method in comparison with other methods, especially in the edge areas of the images.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.27 no.1
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• pp.47-53
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• 2023

Devices such as X-Ray, CT, MRI, scanners, etc. can generate S&P noise from several sources during the image acquisition process. Since S&P noise appearing in the image degrades the image quality, it is essential to use noise reduction technology in the image processing process. Various methods have already been proposed in research on S&P noise removal, but all of them have a problem of generating residual noise in an environment with high noise density. Therefore, this paper proposes a filtering algorithm based on a three-dimensional plane equation by setting the grayscale value of the image as a new axis. The proposed algorithm subdivides the local mask to design the three closest non-noisy pixels as effective pixels, and applies cosine similarity to a region with a plurality of pixels. In addition, even when the input pixel cannot form a plane, it is classified as an exception pixel to achieve excellent restoration without residual noise.

• Spatial Information Research
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• v.2 no.1
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• pp.47-51
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• 1994

The purpose of the study is to establ ish models of land Cover (use) prediction system for development and management of land resources using remotely sensed data as well as ancillary data in the context of multi-dis¬ciplinary approach in the application to CheJoo Island. The model adopts multi-date processing techniques and is a spatial/temporal land-Cover projection strategy emerged as a synthesis of the probability tra-nsition model and the discrimnant-analys is model. A discriminant modelis applied to all pixels in CheJoo landscape plane to predict the most likely change in land Cover. The probability transition model provides the number of these pixels that will convert to different land Cover in a given future time increment. The syntheric model predicts the future change in land Cover and its volume of pixels in the landscape plane.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.191-199
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• 1993

Investigation is given to the detailed procedure of a computer assisted automatic technique for ortho-image generation from digital stereo image data of close-range photographs scanned by the CCD camera scanner. After rectification of geometric scanning errors, the bundle adjustment technique was used to determine the exterior orientation parameters of terrestrial camera. An automatic correlation matching technique was applied to search for the conjugate pixels in digital stereo pairs. And the 3-dimensional coordinates of the corresponding pixels were calculated by the space intersection method. For the generation of ortho-image from the calculated coordinates and right image data values, inverse-weighted-distance average method was used. And the accuracy of the resulting ortho-image was checked by comparing its image coordinates with there corresponding ground coordinates for the check points.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.6
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• pp.70-77
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• 2008

This paper proposes a new text candidate region detection method that uses genetic algorithm based on information of the segmented regions. In image segmentation, a classification of the pixels at each color channel and a reclassification of the region-unit for reducing inhomogeneous clusters are performed. EWFCM(Entropy-based Weighted C-Means) algorithm to classify the pixels at each color channel is an improved FCM algorithm added with spatial information, and therefore it removes the meaningless regions like noise. A region-based reclassification based on a similarity between each segmented region of the most inhomogeneous cluster and the other clusters reduces the inhomogeneous clusters more efficiently than pixel- and cluster-based reclassifications. And detecting text candidate regions is performed by genetic algorithm based on energy and variance of the directional edge components, the number, and a size of the segmented regions. The region information-based detection method can singles out semantic text candidate regions more accurately than pixel-based detection method and the detection results will be more useful in recognizing the text regions hereafter. Experiments showed the results of the segmentation and the detection. And it confirmed that the proposed method was superior to the existing methods.