• 한국컴퓨터정보학회논문지
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• 제14권3호
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• pp.75-82
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• 2009

영상의 비교는 PSNR을 이용하는 것이 일반적이다. PSNR이 35이상일 경우 육안으로 품질 차이를 구분하기 어렵다고 판단한다. 2006년 Lee 등은 원본 이미지 대신 원본 이미지의 MSB 비트열을 공개함으로써 소유권을 증명할 수 있는 프로토콜을 제안하면서, 두 이미지의 MSB 비트열의 유사도를 측정하기 위한 새로운 함수를 사용하였다. 이때의 유사도는 품질을 측정하기 위한 PSNR과는 그 의미가 조금 다른 측면이 있다. 즉, 원본 이미지로부터 생성된 대상 이미지가 현저히 떨어질 경우, PSNR은 매우 낮은 값을 보이지만 품질이 떨어지더라도 유사도 측면에서 본다면 두 영상의 상관관계는 매우 높게 나와야 할 것이다. 본 논문에서는 Lee 등이 제안한 MSB 비교 함수를 수정한 후, ICOR함수를 제안하였으며, 이 함수를 이용하여 두 이미지의 상관관계 판단에 적용할 수 있는지 분석하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제47권2호
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• pp.117-123
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• 2024

This study was to assessment of quality assurance (QA) and noise characteristics of Noise Power Spectrum (NPS) according to the time of by using electronic portal imaging device (EPID) for LINAC (Linear Accelerator). LINAC device was (Varian Clinac^R iX LINAC, USA) used and the were 40 × 30 cm² of detector size were 1024 × 768 photo-electric diode array size. Signal could be obtained the K-space image of white noise images for NPS and we used to Overlap, Non-Overlap, Out of Penumbra, Flatness, Symmetry, Symmetry Rt, Lt methods. The 2013s NPS image Out of Penumbra quantitatively value more than 2013s NPS image Symmetry Rt, Lt methods quantitatively NPS based on the frequency of 1.0 mm^-1. Thus, the 2022s NPS image Out of Penumbra quantitatively value more than 2022s NPS image Symmetry Rt, Lt methods quantitatively NPS based on the frequency of 1.0 mm^-1. The assessment of comparison of white noise for NPS image noise and intensity of this study were to that should be used efficiently of the LINAC EPID detector system for Overlap method for International Electro-technical Commission (IEC).

• 융합신호처리학회논문지
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• 제17권1호
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• pp.26-31
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• 2016

본 논문에서는 소형 카메라 모듈의 화질을 분석하는 시스템을 제안하고 이를 이용하여 렌즈의 성능을 평가하며, 플레어 및 헐레이션 방지 디스크를 삽입하여 렌즈의 성능이 개선되는 효과를 검증한다. 카메라 모듈의 화질을 평가하는 카메라 모듈 화질검증 시스템과 이미지 신호 처리기(Image Signal Processor, ISP) 내부의 레지스터를 제어하는 카메라 모듈 제어 프로그램 및 화질분석 소프트웨어를 개발한다. 제안된 헐레이션 방지 디스크를 삽입된 카메라 모듈의 화질을 기존 카메라 모듈의 화질과 비교평가에서 획득된 영상의 해상도, 밝기, 색재현 등의 성능을 검증한다.

• 한국환경과학회지
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• 제24권4호
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• pp.403-414
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• 2015

This study is daytime and nighttime runoff image data caused by heavy rain on May 27, 2013 at Oedo Water Treatment Plant of Oedo-Stream, Jeju to compute runoff by applying Surface image velocimeter (SIV) and analyzing correlation according to current. At the same time, current was comparatively analyzed using ADCP observation data and fixed electromagnetic surface current meter (Kalesto) observed at the runoff site. As a result of comparison on resolutions of daytime and nighttime runoff images collected, correlation coefficient corresponding to the range of 0.6~0.7 was 6.8% higher for nighttime runoff image compared to daytime runoff image. On the contrary, correlation coefficient corresponding to the range of 0.9~1.0 was 17% lower. This result implies that nighttime runoff image has lower image quality than daytime runoff image. In the process of computing current using SIV, a rational filtering process for correlation coefficient is needed according to images obtained.

• 대한원격탐사학회지
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• 제26권3호
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• pp.325-333
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• 2010

Image registration involves overlapping images of an identical region and assigning the data into one coordinate system. Image registration has proved important in remote sensing, enabling registered satellite imagery to be used in various applications such as image fusion, change detection and the generation of digital maps. The image descriptor, which extracts matching points from each image, is necessary for automatic registration of remotely sensed data. Using contrast enhancement algorithms such as histogram equalization and image stretching, the normalized data are applied to the image descriptor. Drawing on the different spectral characteristics of high resolution satellite imagery based on sensor type and acquisition date, the applied normalization method can be used to change the results of matching interest point descriptors. In this paper, the matching points by scale invariant feature transformation (SIFT) are extracted using various contrast enhancement algorithms and injection of Gaussian noise. The results of the extracted matching points are compared with the number of correct matching points and matching rates for each point.

• 한국산림과학회지
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• 제104권4호
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• pp.685-696
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• 2015

본 연구는 국립공원의 아름다운 풍경사진을 모집단으로 분류한 22개의 아름다운 산림풍경 유형을 유형별 사진의 매수 비율과 인문자원 유형의 제외 등을 통해 선발한 10개의 풍경유형에 대한 선호경향 도출과 이미지 분석을 위해 실시되었다. 풍경유형의 선호도 평가는 편차치(Z척도)와 일대비교법을 사용하였고, 풍경유형의 이미지 분석은 SD법을 사용하였다. 본 연구의 결과를 요약하면 다음과 같다. 첫째, 편차치와 일대비교법에 의한 풍경유형의 선호도 평가 결과, 각 풍경유형의 요소 및 특성이 다름에도 불구하고 대체로 유사한 경향을 나타내어 평가 결과의 일관성을 확인할 수 있었다. 분석 결과, 임내풍경, 계곡과 바위와 같은 풍경에 대한 선호도가 높게 나타났고, 다음으로 능선 풍경, 기암봉우리의 암릉, 폭포와 절벽 풍경에 대한 선호도가 높았다. 한편 고사목 군락의 풍경은 가장 낮게 평가되었다. 둘째, SD법에 의한 풍경유형의 이미지 평가 결과, 요인 1 '신비로운 매력', 요인 2 '화려한 색감', 요인 3 '생동감 다양함'으로 구분되었다. 각 요인에 대한 풍경유형의 분포를 살펴보면 '신비로운 매력'의 이미지는 능선 풍경으로부터, '화려한 색감'의 이미지는 색으로 표현되는 계절감으로부터, '생동감 다양함'의 이미지는 물과 단풍, 기암봉우리의 동적이고 다양한 변화로부터 기인한 것으로 확인되었다.

• 한국의류산업학회지
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• 제11권1호
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• pp.14-23
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• 2009

This study is to analyze the regional differences of sensibility image of wedding dress design for single women of marriageable age in Ulsan and Seoul. The conclusions of this study were as follows. In silhouette, both of two regions were not significant differences but within the same sensibility image there was a bit of differences. In neckline, reminded sweetheart of pure image, yet those of Ulsan reminded sweetheart of feminine image. Both of two regions reminded V of hard image, boat of feminine image, square of hard image, halter of complex image. But within the same sensibility image there was a bit of differences between two regions. Oval was significant differences between two regions. Subject of Ulsan reminded oval of mature image, yet those of Seoul reminded oval of elegance image. It was reminded ruffle of complex image. Subject of Ulsan reminded china of hard image, yet those of Seoul reminded china of calm image. In material, it was not significant differences between two regions, but within the same sensibility image there was a bit of differences between two regions. In detail, subject of Ulsan reminded ruffle of messy image, yet those of Seoul reminded ruffle of complex image. Both of two areas reminded ribbon of pure image, button of pure image. Subject of Ulsan reminded beads of feminine image, yet those of Seoul reminded beads of pure image. In conclusion, it could be said that there was no major differences in sensibility image for wedding dress design between Ulsan and Seoul.

• 동력기계공학회지
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• 제12권6호
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• pp.70-77
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• 2008

The purpose of this study is to compare the quality of digital radiography image with that of classical film images for welded structure in power plants. The CMOS(Complementary Metal Oxide Semiconductor) flat panel detecter and Agfa D5 film are used to image flaw specimens respectively. In the test, CMOS flat panel detector has been determined to have a better image than that of film image. In the IQI(Image Quality Indicator) transmission test, one or two more line can be seen in digital image than in film image. Digital Radiography Test enabled to successfully detect all defects on the weld specimens fabricated with real reheat stem pipe and boiler tube as well. In the specific comparison test, Digital radiography test detected micro flaws in the size of 0.5 mm in length by 0.5 mm in depth. However, film test has limited it to 1.0 mm in length by 1.0 mm in depth. As a result of this study, digital radiography technology is estimated well enough to perform the inspection in the industry with far more cost effective way, compared to the classical film test.

• 한국의류산업학회지
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• 제4권3호
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• pp.243-247
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• 2002

The purposes of this study were 1) to investigate school uniform image preferences and the uniform modifications of male and female high school students, and 2) to find the differences between male and female students in the uniform image preferences and uniform modifications. The subjects used for the study were 195 male and 201 female high school students. The uniform image preferences consisted of three factors: comfortable & simple, unique & individual, and intelligent & classic. The uniform modifications were measured by the modifications in jacket width, sleeve length, shoulder width, slacks(skirt) length, slacks(skirt) width, and slacks(skirt) waist length. The results showed that male and female students were different in regard to uniform image preference; male students preferred unique image than did female students in their school uniforms. In addition, male and female students differed concerning uniform modifications. Generally, female students modified uniforms more than did male students. Finally, the study compared male and female students in regard to the relationships between uniform image preferences and the uniform modifications. For male and female students, the unique image preference was significantly related to the modifications in different parts of uniform.

• 한국멀티미디어학회논문지
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• 제20권2호
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• pp.153-162
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• 2017

Today, weather radar is used as a key tool for modern high-tech weather observations and forecasts, along with a wide variety of ground gauges and weather satellites. In this paper, we propose a frequency transform based weather radar image processing technique to improve the weather radar image damaged by beam blocking and clutter removal in order to minimize the uncertainty of the weather radar observation. In the proposed method, DCT based mean energy correction is performed to improve damage caused by beam shielding, and DWT based morphological image processing and high frequency cancellation are performed to improve damage caused by clutter removal. Experimental results show that the application of the proposed method to the damaged original weather radar image improves the quality of weather radar image adaptively to the weather echo feature around the damaged area. In addition, radar QPE calculated from the improved weather radar image was also qualitatively confirmed to be improved by the damage. In the future, we will develop quantitative evaluation scales through continuous research and develop an improved algorithm of the proposed method through numerical comparison.