• 대한전자공학회논문지SP
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• 제44권2호
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• pp.37-45
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• 2007

국부통계처리에 근거한 금석문영상의 적응영상향상 기법을 제안한다. 영상의 국부통계처리 값들을 영상향상을 위한 적응실현으로 활용하여 평활화와 상세화의 경로를 조정한다. 미세부분에서는 영상이 향상되고 평활영역에서는 잡음이 억제된다 금석 문영상의 모델링을 위해 한지밀착본(韓紙密着本)디지털영상(HSDI, Hanzi squeezed digital image)의 전처리 과정을 수행하였다. HSDI 분석을 통해 국부통계처리 값들을 산출하고 영상을 모델링한다. 본 기법을 HSDI에 적용하여 에지부분의 미세한 변화를 향상시키고 배경영역을 평활시킴으로 결국 문자영역의 시각적 효과를 증대하였다 실험결과들은 제시한 알고리즘이 기존의 영상향상기법보다 우수함을 보여준다.

• 대한원격탐사학회지
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• 제25권6호
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• pp.517-529
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• 2009

Many satellite image fusion techniques have been developed in order to produce a high resolution multispectral (MS) image by combining a high resolution panchromatic (PAN) image and a low resolution MS image. Heretofore, most high resolution image fusion techniques have used IKONOS and QuickBird images. Recently, GeoEye-1, offering the highest resolution of any commercial imaging system, was launched. In this study, we have experimented with GeoEye-1 images in order to evaluate which fusion algorithms are suitable for these images. This paper presents compares and evaluates the efficiency of five image fusion techniques, the $\grave{a}$ trous algorithm based additive wavelet transformation (AWT) fusion techniques, the Principal Component analysis (PCA) fusion technique, Gram-Schmidt (GS) spectral sharpening, Pansharp, and the Smoothing Filter based Intensity Modulation (SFIM) fusion technique, for the fusion of a GeoEye-1 image. The results of the experiment show that the AWT fusion techniques maintain more spatial detail of the PAN image and spectral information of the MS image than other image fusion techniques. Also, the Pansharp technique maintains information of the original PAN and MS images as well as the AWT fusion technique.

• Journal of Information Technology Applications and Management
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• 제14권1호
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• pp.137-144
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• 2007

In this paper, we propose a rotation resistant robust logo embedding watermarking technique. Geometric manipulations make the detection process very complex and difficult. Watermark embedding in the normalized image directly suffers from smoothing effect due to the interpolation during the image normalization. This can be avoided by estimating the transform parameters using image normalization angle and moments, instead of embedding in the normalized image. Conventional rotation resistant schemes that use full frame transform. In this paper we adopt DCT and calculate masking using a spatio-frequency localization of the $8{\times}8$ block DCT coefficients. Experimental results show that the proposed algorithm is robust against rotation process.

• Journal of Mechanical Science and Technology
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• 제14권5호
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• pp.518-529
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• 2000

A detailed and thorough parametric study of digital image correlation method is presented. A theoretical background and development of the method were introduced and the effects of various parameters on the determination of displacement outputs from the raw original and deformed image information were examined. Use of the normalized correlation coefficient, the use of 20 to 40 pixels for a searching window side, 6 variables searching, bi-cubic spline sub pixel interpolations and the use of coarse-fine search are some of the key choices among the results of parametric studies. The displacement outputs can be further processed with two dimensional curve fitting for the data noise reduction as well as displacement gradient calculation.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.590-593
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• 2002

본 논문은 그레이영상에 대해 2D 스플라인 보간법과 2D 웨이블릿 변환을 적용하여 영상모핑을 실현한 연구이다. 프레임 간 특징 점 지정에 스플라인 함수로 B-스플라인 보간법을, 생성되는 중간 영상에 웨이블릿 변환 기법을 적용하였다. 그 결과 스플라인에 의해 유동적인 곡선변형과 웨이블릿 변환에 의해 블럭킹 열화가 제거되어 중간 영상들의 자연스러운 모핑이 이뤄졌다.

• 한국통신학회논문지
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• 제21권4호
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• pp.848-854
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• 1996

Many image display devices allow only a limited number of colors to be simultaneously displayed. in disphaying of natural color image using color palette, it is necessary to construct an optimal color palette and the optimal mapping of each pixed of the original image to a color from the palette. In this paper, we proposed the clustering algorithm using local region block centered one color cluster in the prequantized 3-D histogram. Cluster pairs which have the least distortion error are merged by considering distortion measure. The clustering process is continued until to obtain the desired number of colors. The same as the clustering process, original color value. The proposed algorithm incroporated with a spatial activity weighting value which is reflected sensitivity of HVS quantization errors in smoothing region. This method produces high quality display images and considerably reduces computation time.

• 한국멀티미디어학회논문지
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• 제17권8호
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• pp.923-936
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• 2014

Images can be contaminated with different types of noise, for different reasons. The neighborhood averaging and smoothing by image averaging are the classical image processing techniques for noise removal. The classical spatial filtering refers to the aggregate of pixels composing an image and operating directly on these pixels. To reduce or remove effectively noise in image sequences, it usually needs to use noise reduction filter based on space or time domain such as method of spatial or temporal filter. However, the method of spatial filter can generally cause that signals of objects as the target are also blurred. In this paper, we propose temporal filter using the piece-wise quadratic function model and enhancement algorithm of image quality for the performance improvement of target detection and tracking by heterogeneous noise reduction. Image tracking simulation that utilizes real IIR(Imaging Infra-Red) images is employed to evaluate the performance of the proposed image processing algorithm.

• 한국측량학회지
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• 제36권5호
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• pp.413-422
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• 2018

Many applications using satellite data from high-resolution multispectral sensors require an image fusion step, known as pansharpening, before processing and analyzing the multispectral images when spatial fidelity is crucial. Image fusion methods are to improve images with higher spatial and spectral resolutions by reducing spectral distortion, which occurs on image fusion processing. The image fusion methods can be classified into MRA (Multi-Resolution Analysis) and CSA (Component Substitution Analysis) approaches. To suggest the efficient image fusion method for Pleiades and KOMPSAT (Korea Multi-Purpose Satellite) 3 satellites, this study will evaluate image fusion methods for multispectral and panchromatic images. HPF (High-Pass Filtering), SFIM (Smoothing Filter-based Intensity Modulation), GS (Gram Schmidt), and GSA (Adoptive GS) were selected for MRA and CSA based image fusion methods and applied on multispectral and panchromatic images. Their performances were evaluated using visual and quality index analysis. HPF and SFIM fusion results presented low performance of spatial details. GS and GSA fusion results had enhanced spatial information closer to panchromatic images, but GS produced more spectral distortions on urban structures. This study presented that GSA was effective to improve spatial resolution of multispectral images from Pleiades 1A and KOMPSAT 3.

• 한국정보통신학회논문지
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• 제10권3호
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• pp.549-555
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• 2006

에지검출은 영상처리와 컴퓨터비젼의 매우 중요한 연구분야이다. 그리고 일반적인 에지검출 연산자인 Robert, Sobel, Kirsh등의 연산자는 계단에지를 검출하는데는 적합하나 잡음에 매우 민감한 단점을 가지고 있다. 따라서 본 논문에서는 영상정보척도와 신경회로망을 이용한 잡음에 매우 강한 계단에지 검출방법을 제안한다. 계단에지의 명암도 분포의 차, 방향성, 연속성, 구조성 등의 계단에지의 기본적인 정보특성을 이용한 함수를 BP 신경회로망의 입력벡터로 구성한 결과 매우 위치가 정확한 계단에지를 얻을 수 있었다. 또한 실험 영상으로 장미 영상과 세포영상을 사용하여 매우 만족스런 실험 결과를 얻을 수 있었다.

• Communications for Statistical Applications and Methods
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• 제19권2호
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• pp.225-235
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• 2012

다양한 이유로 인하여 발생하는 영상 잡음은 영상의 화질을 악화시키므로 발생한 잡음을 제거, 감소하는 것이 영상처리 분야에서 매우 중요한 문제이다. 이러한 문제를 해결하는데 가장 근본적인 어려움은 영상 정보에서 제거해야할 잡음과 보존해야 할 신호를 구별하는 것이 쉽지 않다는 것이다. 단순평활법과 같은 잡음 제거과정은 영상을 개선하는데 사용되는 기초적이고 중요한 방법이지만 영상을 오염시키는 잡음의 크기를 고려하지 않는 결점이 있다. 즉, 이러한 방법을 사용하면 잡음을 감소시키는 효과와 함께 잡음이 적거나 없는 부분까지도 열화되어 영상이 흐릿해지는 단점을 보이게 된다. 본 연구에서는 입력 영상에서 신호와 잡음을 효과적으로 구별하여 잡음의 상대적인 크기에 따라 적응적으로 잡음을 제거할 수 있는 방법을 블록 방법을 이용하여 제안한다. 모의실험 결과, 본 연구에서 제안하는 알고리즘에 의해 적응적으로 잡음을 제거함으로써 전체적인 영상의 질이 개선되는 것을 확인하였다.