• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.681-688
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• 2016

This study assess their quality of radiation on analysis of the spectrum of resolution suggesting IEC 61267 in radiation quality that RQA3, RQA5, RQA7, RQA9 and combination of clinical condition using several quality of radiation. In experiments edge method first, the spatial resolution assessment used image of the additional filter and SID is obtained the IEC 62220-1, spatial resolution and sharpness of the obtained image was evaluated in the MTF value 10%(0.1), MTF value 50%(0.5) using a Matlab program. Second, MCNPX simulation used spatial resolution analysis was radiation quality particle fluence and spectrum analysis in energy. As a result, make use of additional filter, image quality evaluation of SID that RQA3 radiation quality combination qualification is higher spatial resolution and sharpness make unused of additional filter and SID 100cm. RQA7 radiation quality combination qualification is higher that spatial resolution make unused of additional filter and SID 150cm. RQA9 radiation quality combination qualification is higher that spatial resolution and sharpness make used of additional filter and SID 180cm. spectrum analysis of radiation quality by reducing consequent errors occurring in the experiment that error due to the reproducibility of the X-ray tube, occur in an error of correction the detector suggest ideal conditions from spectrum analysis through MCNPX simulation. In conclusion, by suggesting spatial resolution and sharpness of result for various radiation quality, It provide basic data that radiation quality condition and quantitative assessment method for laboratory in clinical using detector evaluation.

• ETRI Journal
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• v.41 no.1
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• pp.93-108
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• 2019

Guaranteeing interoperability between devices and applications is the core role of standards organizations. Since its first JPEG standard in 1992, the Joint Photographic Experts Group (JPEG) has published several image coding standards that have been successful in a plethora of imaging markets. Recently, these markets have become subject to potentially disruptive innovations owing to the rise of new imaging modalities such as light fields, point clouds, and holography. These so-called plenoptic modalities hold the promise of facilitating a more efficient and complete representation of 3D scenes when compared to classic 2D modalities. However, due to the heterogeneity of plenoptic products that will hit the market, serious interoperability concerns have arisen. In this paper, we particularly focus on the holographic modality and outline how the JPEG committee has addressed these tremendous challenges. We discuss the main use cases and provide a preliminary list of requirements. In addition, based on the discussion of real-valued and complex data representations, we elaborate on potential coding technologies that range from approaches utilizing classical 2D coding technologies to holographic content-aware coding solutions. Finally, we address the problem of visual quality assessment of holographic data covering both visual quality metrics and subjective assessment methodologies.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.3
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• pp.75-83
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• 2016

There are various types of disasters now, and accordingly it is practically difficult to manage all types of disasters effectively. If we are able to reconstruct the disaster event and investigate the cause, it may be possible to prepare the recurrence of similar patterns of disasters. The vehicle-based system equipped with state-of-the-art sensors has been proposed in order to reconstruct the disaster site as much as possible and help the disaster investigator to analyze the cause of the disaster by providing high-quality information. However, the data quality obtained from the sensors can be lowered due to unpredictable circumstances of disaster site. In this aspect it is essential to provide practical procedures that assess and analyze the performance of the equipment on site. In this paper, we selected critical elements of performance that can evaluate the vehicle-based image acquisition system, since it is the most critical piece of information in the disaster sites. The quality of the images obtained from vehicle-based image system was analyzed and verified on the test site. From the results of spatial resolution based on GRD(Ground Resolved Distance), we were able to identify maximum 5mm of spatial resolution at a distance of 70m distance. The result of field test is expected to be used for data acquisition plan in future disaster situations.

• The Korean Journal of Nuclear Medicine Technology
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• v.28 no.1
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• pp.49-56
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• 2024

Purpose: When performing nuclear medicine examinations, body wraps or plastic supports are used to support and immobilize the patient's upper extremities to prevent patient safety accidents. However, the existing plastic supports compromised patient and staff safety, including finger entrapment and falls. Moreover, the body wrap provided by manufacturers compromised image quality such as upper extremities cutoff during whole body bone scan. Therefore, a new design of body wrap was developed to improve the issue, and this study aims to evaluate the usability of this medical body wrap. Materials and Methods: To evaluate the usability of the newly designed medical body wrap, a quality assessment of whole body bone scan images and a user satisfaction survey were conducted. Adult patients (male:female=129:152, age: 60.3±12.4 years, BMI: 24.0±4.2) aged 16 years or older who underwent a whole body bone scan during two periods: June to July 2022 (before improvement, n=139) and June to July 2023 (after improvement, n=142) were randomly selected for image quality evaluation. Five radiotechnologists visually evaluated the posterior view of the whole body bone image, including the left and right elbow (2 points), arm (2 points), whether the hand is extended (2 points), whether the hand is included (2 points), and the number of visible fingers (10 points), with a total of 18 points, which were converted to 100 points and analyzed for difference before and after improvement using an independent sample t-test. The user satisfaction questionnaire was evaluated using a 5-point Likert scale among 16 radiotechnologists from three general hospitals who experienced the new body wrap. Results: The image quality assessment was 82.0±13.8 before the improvement and 89.3±10.1 after the improvement, an average of 7.3 points higher, with a statistically significant difference (t=5.02, p<0.01). The user satisfaction survey showed an overall satisfaction rating of 4.1±0.8 for ease of use, 3.8±0.7 for scan preparation time, 3.9±0.7 for patient safety, 3.8±1.2 for scan accuracy, and 4.2±0.7 for recommendation (87.5% questionnaire response rate). Conclusion: The developed body wrap showed higher image quality and user satisfaction compared to the old method. Considering these results, it is deemed that the new body wrap may be more useful than existing methods.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.11a
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• pp.81-83
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• 2015

객관적 영상 화질 측정(Image Quality Assessment: IQA)방법은 영상 화질 최적화 문제해결을 목적으로 하는 영상 처리 및 컴퓨터 비전 분야에 매우 중요하게 사용된다. 이를 위해, 저복잡도, 고성능 및 좋은 수학적 특성(예를 들어, 척도성(metricability), 미분가능성(differentiability) 및 볼록 성질(convexity))을 모두 만족시키는 객관적 IQA 방법이 활발히 연구되어 왔다. 그러나, 위해 위에서 언급한 좋은 수학적 특성을 가지는 대부분의 객관적 IQA 방법들은 좋은 수학적 특성을 만족시키기 위해 상당한 예측성능의 감소를 초래했다. 본 논문은 위에서 언급한 좋은 수학적 특성을 모두 만족시키면서, 예측 성능이 향상된 새로운 IQA 방법을 제안한다. 인간 시각 체계의 감수영역은 광도 입력에 대해 공간 도메인에서 미분 형태의 응답을 가지므로, 제안 방법은 이러한 시각 체계 응답을 모방하여 기울기 연산자를 도입한다. 제안한 방법에서 도입한 기울기 연산자는 매우 단순하게 설계되어, 계산 복잡도가 매우 낮다. 광범위한 실험 결과, 제안하는 IQA 방법은 기존 수학적 특성이 좋은 IQA 방법들 대비 더 좋은 성능을 보이면서 계산 복잡도 또한 낮았다. 따라서 제안 IQA 방법은 다양한 영상 화질 최적화 문제에 매우 효과적으로 적용될 수 있다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.10-15
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• 1998

In Japan, digital HDTV services via broadcasting satellite are planned to start in 2000. NHK has developed an HDTV codec conforming to the MPEG-2 $MPHL$ and estimated the coded picture quality with diverse image sequences. This paper shows the codec specifications and presents the result of the picture quality assessment.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.565-572
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• 2023

This study was conducted to analyze the status radiological imaging examinations assessment in Korea medical institutions conducted in the public sector and suggest a direction for improvement. Among the assessment of medical institutions, the main assessment related to radiographic imaging examinations are the certification evaluation of medical institutions and the adequacy assessment of radiographic imaging examinations. The certification evaluation of medical institutions evaluates the image inspection operation process, provision of accurate results, and compliance with safety management procedures. In the assessment of adequacy of radiographic imaging examinations, structural indicators related to manpower and equipment, patient evaluation implementation rate, and exposure reduction programs were included. However, for safer and higher-quality radiological imaging examinations, it is necessary to increase the participation rate of medical institutions in certification evaluations. In addition, it is necessary to improve the manpower indicator, and incentive payments can be considered to induce quality improvement of medical institutions in the future. Integrated management of radiation exposure at the national level should also be carried out simultaneously.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.6
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• pp.243-250
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• 2023

Chest X-ray is radiological examination for xeamining the lungs and haert, and is particularly widely used for diagnosing lung disease. Since the quality of these chest X-rays can affect the doctor's diagnosis, the process of evaluating the quality must necessarily go through. This process can involve the subjectivity of radiologists and is manual, so it takes a lot of time and csot. Therefore, in this paper, based on the chest X-ray quality assessment guidelines used in clinical settings, we propose a tool that automates the five quality assessments of artificial shadow, coverage, patient posture, inspiratory level, and permeability. The proposed tool reduces the time and cost required for quality judgment, and can be further utilized in the pre-processing process of selecting high-quality learning data for the development of a learning model for diagnosing chest lesions.

• Journal of the Korean Society of Radiology
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• v.3 no.4
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• pp.13-21
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• 2009

The Magnetic Resonance Imaging (MRI) systems consist of various parameters. Among them, the image quality can be arguably the most important part of the systems. As the other components in MRI systems have been developed and evolved, the MRI image quality has been advanced remarkably. And, the radiation imaging system is being converted from the Film to the digital method, which drives the computerization of many hospitals. The management of the tremendous radiation images becomes more critical. The data compression is used to store such large data in a network server. When the image files are compressed, the image quality degrades comparing to its original images. Even slight quality degradation of a medical image could cause an erroneous diagnosis, so the images must be handled carefully. This thesis studied the image assessment methods of comparing the quality of the compressed image to its original, and the quality of the original and the displayed images of the MRI systems via PSNR with actual medical images used in hospitals. As a result, no noticeable quality degradation was found comparing the compressed images with various digital compression methods and the original images. However, it was a different story comparing the original images and the displayed images on MRI monitors. Some noise or image distortion was visible using any regular CRT or LCD monitors were used while the special monitors designed for the MRI imaging and medical images displayed high definition images.

• The Journal of the Korea Contents Association
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• v.13 no.1
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• pp.9-18
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• 2013

In order to measure the parameters of consumers' preferred image quality, this research suggests image quality assessment factors; dynamic range, color, and contrast. They have both physical image quality factors and psychological characteristics from the previous researches. We found out the specific ranges of preferred image quality metrics. As a result, Digital Zone System meant for dynamic range generally shows 6~10 stop ranges in portrait, nightscape, and landscape. Total RGB mean values represent in portrait (67.2~215.2), nightscape (46~142), and landscape (52~185). Portrait total RGB averages have the widest range, landscape, and nightscape, respectively. Total scene contrast ranges show in portrait (196~589), nightscape (131~575), and landscape (104~767). Especially in portrait, skin tone RGB mean values are in ZONE V as the exposure standard, but practically image consumers' preferred skin tone level is in ZONE IV. Also, total scene versus main subject contrast ratio represents 1:1.2; therefore, we conclude that image consumers prefer the out-of-focus effect in portrait. Throughout this research, we can measure the preferred image quality metrics ranges. Also, we expect the practical and specific dynamic range, color, and contrast information of preferred image quality to positively influence product development.