• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.453-469
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• 2016

Many image fusion quality assessment techniques, which include Wald's, QNR and Khan's protocols, have been proposed. A total procedure for the quality assessment has been defined as the quality assessment protocol. In this paper, we compared the performance of the three protocols using KOMPSAT-2/3/3A satellite images, and tested the applicability to the fusion quality assessment of the KOMPSAT satellite images. In addition, we compared and analyzed the strengths and weaknesses of the three protocols. We carried out the qualitative and quantitative analysis of the protocols by applying five fusion methods to the KOMPSAT test images. Then we compared the quantitative and qualitative results of the protocols from the aspects of the spectral and spatial preservations. In the Wald's protocol, the results from the qualitative and quantitative analysis were almost matched. However, the Wald's protocol had the limitations 1) that it is timeconsuming due to downsampling process and 2) that the fusion quality assessment are performed by using downsampled fusion image. The QNR protocol had an advantage that it utilizes an original image without downsampling. However, it could not find the aliasing effect of the wavelet-fused images in the spectral preservation. It means that the spectral preservation assessment of the QNR protocol might not be perfect. In the Khan's protocol, the qualitative and quantitative analysis of the spectral preservation was not matched in the wavelet fusion. This is because the fusion results were changed in the downsampling process of the fused images. Nevertheless, the Khan's protocol were superior to Wald's and QNR protocols in the spatial preservation.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2021.06a
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• pp.212-215
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• 2021

본 논문에서는 6 Fisheye lens 원본 영상에 대하여 Insta360 stitcher, AutoStitch[4], As-Projective-AsPossible(APAP)[5] 스티칭 방법으로 360 도 파노라마 영상을 생성하고 기하학적 왜곡과 컬러 왜곡을 비교 평가한다. 360 도 파노라마 Image Quality Assessment(IQA) 메트릭으로 Natural Image Quality Evaluator(NIQE)[6], Blind/Referenceless Image Spatial Quality Evaluator (BRISQUE)[7], Perception based Image Quality Evaluator(PIQE)[8], Feature Similarity(FSIM)[9] 그리고 high frequency feature 에 대한 Structural Similarity(SSIM)[10]을 측정하여 정량적 평가를 하며 정성적인 비교를 통하여 파노라마 영상의 품질과 평가 메트릭에 대한 벤치마크를 제공한다.

• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.141-142
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• 2016

의료 기관에서 정확한 진단하기 위해 아날로그 시스템인 Film System보다 Digital System을 선호하고, 장비의 설치 또한 Digital System으로 많이 보급이 되고 있다. 장비가 많이 보급이 되었지만 현재 장비에 대한 안전관리나 품질관리는 미흡하다고 할 수 있다.이에 본 연구는 Digital System의 품질관리의 중요성을 알리고, 품질관리의 항목을 설정하여, 기준 값을 제시하고자 3개월 동안 SNR, MTF, DQE를 측정한 결과 다음과 같이 나타났다. 1달은 SNR 4.02, MTF 50% 4.6lp/mm, DQE는1.4로 측정이 되었다. 3주후 SNR은 3.55, MTF 50% 3.0lp/mm, DQE는 0.7로 나타났다. 3개월 뒤 SNR은 3.45, MTF 50% 2.1lp/mm, DQE는 0.5로 나타났다. 시간이 지나갈수록 영상의 디지털영상의 물리적 평가들이 저하되는 것으로 나타났다. 시간이 지나감에 따라 의료영상이 저하됨에 따라 안전관리 뿐만 아니라 영상의 품질관리도 같이 이루어져야 할 것이다.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.111-116
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• 2007

본 논문에서는 인터넷전화 품질평가를 위한 국내 동향에 대하여 기술하고, BcN영상전화 서비스에 대한 SLA 품질지표 및 품질기준을 국내외 동향 및 기준표준화에 근거하여 마련하고 이를 검증하기 위한 품질측정 방법을 제시하고자 한다. 이를 통해서 영상전화 서비스의 SLA 품질기준이 조기에 마련되어 국내 통신사업자들의 이용약관에 반영되기를 기대한다. 따라서 본 논문의 목차는 서론, SLA 개요, 영상전화 서비스의 품질지표 및 기준, 품질지표별 측정방법 및 시험측정 결과에 대하여 기술하였다.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.592-600
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• 2016

AAPM CT performance for special medical equipment quality control checks using a standard phantom for evaluation, using the evaluator's subjective assessment as to minimize errors due computerized assessment program to evaluate their usefulness. Phantom for evaluation AAPM CT Performance Phantom: was used, the default shooting conditions are the same as quality control checks. And, we use IMAGE J to evaluate the program. Quantitative evaluation with CT attenuation coefficient and the noise measurement, the uniformity measurement, the slice thickness measurement, contrast resolution of the measurement, a phantom image of the spatial resolution determined by the evaluation program is evaluated as self-extracting the result after processing the image, CT uniformity measurement for the evaluation that was smaller and the standard deviation of a video image processing more uniform slice thickness measurements it is difficult to evaluate due to the difference of the ratio of the measured value of the phantom image. Contrast resolution was measured cylindrical diameter 6th evaluate the shape of a circle obtained a mean value and a standard deviation of diameters, the spatial resolution of the group of source, including acceptance criteria automatically extracted result as a result of both the number of the extracted circularIt appeared. Evaluate the source image and video processing, and video to qualitative evaluation by gross were processed video image is shown excellent results. If the evaluators in order to minimize the errors of subjective judgment based on the results of the above should be done with a quantitative evaluation and qualitative evaluation utilizes a computerized assessment program is considered that further evaluation be made more efficient.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1869-1876
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• 2009

Scanner which is a kind of optical devices is used to convert paper documents into document image files. The assessment of scanned document image is performed to check if there are any modification on document image files in scanning process. In assessment of scanned documents, user checks the degree of skew, noise, folded state and etc This paper proposed to how to measure geometrical modifications of document image in scanning process. In this study, we check the degree of modification in document image file by image processing and we compare the evaluation value which means the degree of modification in each items with OCR success ratio in a document image file. To analyse the correlation between OCR success ratio and the evaluation value which means the degree of modification in each items, we apply Pearson Correlation Coefficient and calculate weight value for each items to score total evaluation value of image modification degrees on a image file. The document image which has high rating score by proposed method also has high OCR success ratio.

• Journal of Digital Convergence
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• v.13 no.11
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• pp.179-185
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• 2015

In this paper, we research the IPTV that is the convergence technique of TV and network technique and performed the performance evaluation of picture quality of IPTV in the situation of increasing the network traffic in the Internet environment. To do this, we constructed the mock Internet network similar to the real Internet environment and measured the quality of received video using V-Factor model according to the increase of network traffic, and analyzed the result of the experiment. Making use of the result of this paper for the threshold value of V-Factor, the measured factor of network performance, the measured factor of video performance in the watchable IPTV video quality.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.97-102
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• 2007

Satellite performance can be evaluated by satellite product. When satellite development technology is in developing, most of efforts focus on success of satellite operation and safety. But, more and more efforts are focused on satellite performance and mission success. Especially quality of the image which is delivered to user is very important factor. In this paper, generating method for simulated image in the point of MTF is described.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.11a
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• pp.69-72
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• 2008

본 논문에서는 PSNR 이 다른 어떤 척도보다도 화질의 평가에 있어서 중요하다는 전제하에 비쥬얼리듬 (VR) 정보를 이용하여 원본영상이 가용하지 않은 일반 시청자들의 STB 재생영상으로부터 PSNR 을 추정하는 방법을 제안하였다. VR 로부터 추정한 PSNR 값이 매 프레임 별로 2 차원 재생영상으로부터 구한 PSNR 과 같지는 않으나 시청자들이 평균적으로 어느 정도의 화질로 시청하고 있는지 비교적 정확하게 모니터링이 가능하다. 제안된 방법은 감소기준법(RR) 영상품질 측정방법으로 사용될 수 있다. STB 은 단순히 재생영상으로부터 VR 정보만 추출해서 서버로 전송하는 역할만 수행하면 되고, 나머지 연산은 품질관리 서버에서 수행하므로 자원이 부족한 STB 의 부담을 경감하면서도 효율적으로 품질을 모니터링할 수 있는 장점이 있다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.3
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• pp.217-226
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• 2022

In the view of the application of high-precision spatial information production, UAV (Umanned Aerial Vehicle)-Photogrammetry has a problem in that it lacks specific procedures and detailed regulations for quantitative quality verification methods or certification of captured images. In addition, test tools for UAV image quality assessment use only the GSD (Ground Sample Distance), not MTF (Modulation Transfer Function), which reflects image resolution and contrast at the same time. This fact makes often the quality of UAV image inferior to that of manned aerial image. We performed MTF and GSD analysis simultaneously using a siemens star to confirm the necessity of MTF analysis in UAV image quality assessment. The analyzing results of UAV images taken with different payload and sensors show that there is a big difference in σ_MTF values, representing image resolution and the degree of contrast, but slightly different in GSD. It concluded that the MTF analysis is a more objective and reliable analysis method than just the GSD analysis method, and high-quality drone images can only be obtained when the operator make images after judging the proper selection the sensor performance, image overlaps, and payload type. However, the results of this study are derived from analyzing only images acquired by limited sensors and imaging conditions. It is therefore expected that more objective and reliable results will be obtained if continuous research is conducted by accumulating various experimental data in related fields in the future.