• 한국방사선학회논문지
• /
• 제16권7호
• /
• pp.927-934
• /
• 2022

본 연구는 간 초음파 영상을 활용하여 정량적인 측정 분석을 통해 조직 내 감쇠 지수, 조직 내 산란 분포지수 값 분석과 함께 초음파 영상 소견 간 일치도를 알아보고자 하였다. 2022년 8월부터 2022년 10월까지 지방간이 의심되어 간 초음파 검사 처방을 받은 45명의 환자를 대상으로 간 초음파 검사를 시행하였다. 연구결과, 초음파 영상 소견과 조직 내 감쇠 지수 간 일치도 분석 결과 Kappa 값이 0.82(p<0.05)로 두 검사 방법 간 매우 높은 일치도를 보였다. 또한, 초음파 영상 소견과 조직 내 산란 분포 지수 간 일치도 분석 결과에서도 Kappa 값이 0.642(p<0.05)로 두 검사 방법 간 높은 일치도를 보였다. 지방간 예측 시 간 초음파 소견 및 정량적인 초음파 검사 기법인 조직 내 감쇠 지수, 조직 내 산란 분포 지수를 활용한다면 지방간 환자의 진행 정도를 판단할 때 도움이 될 수 있을 것으로 생각된다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
• /
• pp.180-182
• /
• 2005

Fingerprint-based identification is known to be used for a very long time. Owing to their uniqueness and immutability, fingerprints are today the most widely used biometric features. Therefore, recognition using fingerprints is one of the safest methods as a way of personal identification. But fingerprint identification system has a critical weakness. Since the fingerprint identification time dramatically increase when we compare the unknown fingerprint's minutiae with fingerprint database's minutiae. In this paper, a ridge orientation extraction method using Index table is proposed to solve the problem. The goal of fast direction image extraction is to reduce the identification time and to improve the clarity of ridge and valley structures of input fingerprint image.

• 대한전자공학회논문지
• /
• 제25권7호
• /
• pp.826-835
• /
• 1988

In this paper, we analyze the generation of an image pyramid as a 2-dimensional decimation-interpolation process, and suggest a performance index of FIR filter for decimation and interpolation filter. Until now, most deciamtion and interpolation filters are designed via the approximation of the impulse response of an ideal filter. In this paper, however, we propose a new performance index that minimizes the maximum frequency-weighted mean square error between the desired and the generated interpolated signal, and propose an optimal half-band filter based on the proposed performance index as an example. Some simulation results with real images show that the proposed optimal half-band filter yields a higher PSNR as well as the more preferable image quality, in comparison with other currently used filters with the same computational complexity.

• 한국정보통신학회논문지
• /
• 제8권1호
• /
• pp.102-107
• /
• 2004

본 논문에서는 시각적. 공간적 정보로 구성된 이미지의 효율적인 검색을 위하여, 색상특징정보와 모양특징정보를 멀티인덱스키로 구성하고 질의 이미지의 입력 시 자동으로 색상특징정보와 모양특징정보를 동시에 추출하여 유사한 이미지를 검색할 수 있는 내용기반 이미지 검색시스템을 제안하였다. 제안된 시스템은 기존의 단일 특징정보를 이용한 방법이나 2가지 이상의 특징정보를 단계적으로 검색하는 방법에 비해 향상된 효율성과 신속성을 보이고 있다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.213-217
• /
• 1998

This study overviews existing evaluation methods of classification accuracy using confusion matrix proposed by Cohen in 1960's, and proposes ISDd(Index of Spatial Distribution by distance) and ISDs(Index of Spatial Distribution by scatteredness) for the evaluation of spatial distribution of satellite image classification errors, which has not been tried yet. Index of spatial distribution offers the basis of decision on adoption/rejection of classification results at sub-image level by evaluation of distribution, such as status of local aggregation of misclassified pixels. So, users can understand the spatial distribution of misclassified pixels and, can have the basis of judgement of suitability and reliability of classification results.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2004년도 학술발표회
• /
• pp.1300-1304
• /
• 2004

This study is to present a method of flood damaged area detection by the typhoon RUSA (August 31 - September 1, 2002) using Landsat 7 ETM+ and Landsat 5 TM images. Two images of Sept. 29, 2000 and Sept. 11, 2002 (path 115, row 34) were prepared for Gangreung, To identify the damaged areas, firstly, the NDVI (Normalized Difference Vegetation Index) of each image was computed, secondly, the NDVI values were reclassified as two categories that the negative index values including zero are the one and the positive index values are the other, thirdly the reclassified image before typhoon is subtracted from the reclassified image after typhoon to get DNDVI (Differential NDVI). Some part of urban and agricultural were classified into damaged area due to typhoon RUSA in Gangreung, $18.8km^2$ and $17.7km^2$ respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제14권3호
• /
• pp.1043-1064
• /
• 2020

A kind of Subjective Imaging Effect Assessment (SIEA) method and its applications on intelligent imaging terminal design in engineering site are presented. First, some visual assessment indices are used to characterize the imaging effect: the image brightness, the image brightness uniformity, the color image contrast, the image edge blur, the image color difference, the image saturation, the image noise, and the integrated imaging effect index. A linear weighted function is employed to carry out the SIEA computation and the Analytic Hierarchy Process (AHP) technique is used to estimate its weights. Second, a SIEA software is developed. It can play images after the settings of assessment index or assessment reaction time, etc. Third, two cases are used to illustrate the application effects of proposed method: the image enhancement system design for surveillance camera and the imaging environment perception system design for intelligent lighting terminal. A Prior Sequential Stimulus (PSS) experiment is proposed to improve the evaluation stability of SIEA method. Many experiment results have shown the proposed method can realize a stable system design or parameters setting for the intelligent imaging terminal in engineering site.

• Journal of the Optical Society of Korea
• /
• 제7권4호
• /
• pp.234-239
• /
• 2003

Objective methods to assess quantitatively port wine stain (PWS) blanching in response to laser therapy are needed to improve laser therapeutic outcome. Previous studies have attempted to assess objectively PWS color based on point measurement devices. To date, these approaches have typically been limited by a number of factors such as small test area and need for contact. To address these issues, a polarization spectral imaging system and an image analysis method have been developed to evaluate quantitatively erythema and melanin content distribution in skin. The developed polarization spectral imaging system minimizes artifacts such as glaring, shadowing, and non-uniform illumination that interfere with image fidelity. Furthermore, the image analysis method has been employed to get images of skin melanin and erythema indices from the acquired color images for quantitative analysis. Finally, using PWS patient color image, the effectiveness in laser treatment of PWS was evaluated by calculating relative erythema index image that is the relative erythema index of PWS region to the normal region. The developed device and analysis method appears to be a simple and effective method for quantitative analysis of PWS blanching.

• Radiation Oncology Journal
• /
• 제35권2호
• /
• pp.101-111
• /
• 2017

The number of imaging data sets has significantly increased during radiation treatment after introducing a diverse range of advanced techniques into the field of radiation oncology. As a consequence, there have been many studies proposing meaningful applications of imaging data set use. These applications commonly require a method to align the data sets at a reference. Deformable image registration (DIR) is a process which satisfies this requirement by locally registering image data sets into a reference image set. DIR identifies the spatial correspondence in order to minimize the differences between two or among multiple sets of images. This article describes clinical applications, validation, and algorithms of DIR techniques. Applications of DIR in radiation treatment include dose accumulation, mathematical modeling, automatic segmentation, and functional imaging. Validation methods discussed are based on anatomical landmarks, physical phantoms, digital phantoms, and per application purpose. DIR algorithms are also briefly reviewed with respect to two algorithmic components: similarity index and deformation models.

• Journal of information and communication convergence engineering
• /
• 제7권4호
• /
• pp.535-538
• /
• 2009

Speckle noise reduction for ultrasound CT image using morphological adaptive median filtering based on edge preservation is presented in this paper. Speckle noise is multiplicative feature and causes ultrasound image to degrade widely from transducer. An input image is classified into edge region and homogeneous region in preprocessing. The speckle is reduced by morphological operation on the 2D gray scale by using convolution and correlation, and edges are preserved. The adaptive median is processed to reduce an impulse noise to preserve edges. As the result, MAM of the proposed method enhances the image to about 10% in comparison with Winner filter by Edge Preservation Index and PSNR, and 10% to only adaptive median filtering.