• Title/Summary/Keyword: 촬영조건

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The Effects of Roll Misalignment Errors, Shooting Distance, and Vergence Condition of 3D Camera on 3D Visual Fatigue (시각피로 모형: 카메라의 회전오차, 촬영 거리, 수렴 조건이 입체 시각피로에 미치는 영향)

  • Li, Hyung-Chul O.;Park, JongJin;Kim, ShinWoo
    • Journal of Broadcast Engineering
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    • v.18 no.4
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    • pp.589-598
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    • 2013
  • In order to understand 3D visual fatigue, it is necessary to examine the visual fatigue induced by camera parameters as well as that induced by a pre-existing 3D content. In the present study, we examined the effects of camera parameters, such as roll misalignment error, shooting distance and vergence condition on 3D visual fatigue and we modelled it. The results indicate that roll misalignment error, shooting distance and vergence condition affect 3D visual fatigue and the effect of roll misalignment error on 3D visual fatigue is evident specifically when screen disparity is relatively small.

Facial Exposure Dose Assessment During Intraoral Radiography by Radiological Technologists (구내 촬영시 방사선사의 안면부 피폭선량 측정)

  • Yu, Hwan;Yang, Hanjoon
    • Journal of radiological science and technology
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    • v.37 no.3
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    • pp.195-201
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    • 2014
  • The study examined the changes in the decreased facial exposure dose for radiological technologists depending on increased distance between the workers and the X-ray tube head during intraoral radiography. First, the facial phantom similar to the human tissues was manufactured. The shooting examination was configured to the maxillary molars for adults (60kVp, 10mA, 50msec) and for children (60kVp, 10mA, 20msec), and the chamber was fixed where the facial part of the radiation worker would be placed using the intraoral radiography equipment. The distances between the X-ray tube head and the phantom were set to 10cm, 15cm, 20cm, 25cm, 30cm, 35cm, and 40cm. The phantom was radiated 20 times with each examination condition and the average scattered doses were examined. The rate at the distance of 40cm decreased by about 92.6% to 7.43% based on the scattered rays radiated at the distance of 10cm under the adult conditions. The rate at the distance of 40cm decreased by about 97.6% to 2.58% based on the scattered rays radiated at the distance of 10cm under the children conditions. Protection from the radiation exposure was required during the dental radiographic examination.

Research on the Actual Condition of Mammograpgy and Space Scattered Dose in Mammography Room (유방촬영의 실태와 유방촬영실의 공간산란선량에 관한 조사 연구)

  • Lee, In-Ja;Park, Kye-Yeon;Kim, Sung-Soo
    • Journal of radiological science and technology
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    • v.29 no.1
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    • pp.21-28
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    • 2006
  • I made inquires about mammographic equipments and circumstances of mammography rooms in the 64 medical facilities in areas of Seoul and Kyong Gi Do. Moreover I had experments about exposure dose with patients and radiologic technologists. so there is the data indicated follows. 1. There are inclined to improve in quality and function of mammographic equipments, it has been proven that s/f system exchanged to DR system. 2. It is certain that the number of examinations are becoming increasingly significant. 3. The Space Scattered Dose of mammography rooms are much more larger than portable equipments. 4. I worry about the affection of expose dose about Space Scattered Dose of mammography room. 5. There is need of study how to cope with the situation about increasing exposure dose of radiologic technologists in small space and numeruous number of examinations.

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Evaluation of Dose Reduction and Maintaining Image Quality according to Exposure Factors of Cone Beam Computed Tomography (콘빔전산화단층촬영에서 노출 조건에 따른 화질 유지 및 선량 감소에 대한 평가)

  • Han, Jin-Woo
    • Journal of the Korean Society of Radiology
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    • v.14 no.4
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    • pp.353-360
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    • 2020
  • This research aims at suggesting exposure condition that shows maintaining the value of the physical image quality factor by decreasing tube voltage and tube current from the standard exposure condition(80 kV, 7 mA) of a CBCT apparatus. To measure the value of the physical image quality factor, modular transfer function(MTF) was analyzed and dose-area product(DAP) was used for the measurement of exposure dose. CBCT images of a Sedentex IQ phantom were obtained under 15 exposure conditions of different combination of tube voltage(80, 78, 76 kV) and tube current(7, 6, 5, 4, 3 mA) and MTF 10 was calculated under each exposure conditions. There were no significant differences in MTF 10 under 80 kV-6 mA, 80 kV-5 mA exposure conditions in comparison with standard exposure condition. Based on the results of this research, 80 kV-5 mA condition are expected to be able to reduce exposure dose with maintaining the value of the physical image quality factor of the standard exposure condition.

Radiologic Diagnosis of Temporomandibular Joint (측두하악관절의 영상진단)

  • Park, Hyok;Chung, A-Young;Jung, Da-Woon;Kim, Seong-Taek
    • Journal of Dental Rehabilitation and Applied Science
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    • v.28 no.3
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    • pp.291-299
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    • 2012
  • There are many kinds of techniques for imaging temporomandibular joints. None of them for imaging "best fit" for every patient of temporomandibular disorder is recommended ideally. It is more important to be able to select the modality that is most adequate and appropriate for a given clinical issue.

Estimation of Fingerprint Image Quality in Accordance with Photographing Conditions (촬영 조건에 따른 지문 사진의 품질에 관한 연구)

  • Yu, Je-Seol;Jeon, So-Young;Kim, Kyu-Yeon;Kim, Ji-Yeon;Kim, Chae-Won;Jang, Jake
    • The Journal of the Korea Contents Association
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    • v.17 no.6
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    • pp.287-295
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    • 2017
  • This study is aimed at observing effects of fingerprint image quality on various photographing conditions in the aspect of resolution. Discrimination between two friction ridges plays an important role in the value of fingerprint image, and it can be confirmed with quantification of pixels of boundary region which is existing between two friction ridges. In this study, several factors were estimated with same fingerprint image using Adobe photoshop CS 6 for analysis: changes of image quality by ISO, movement when photographing, and photographers' experience and skill. Consequently, there was no significant change of image quality by ISO. Furthermore, there was no significant difference in the hand-held images between crime scene investigators and laymen, yet there was significant difference between hand-held images and images using tripod in the aspect of resolution. This study shows that using tripod is very important in forensic fingerprint photography through empirical methods.

고해상도 위성 탑재 카메라의 광학계 개념설계 기법

  • 장홍술
    • Bulletin of the Korean Space Science Society
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    • 2004.04a
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    • pp.80-80
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    • 2004
  • 해상도가 높아질수록 위성 탑재 카메라의 광학적 설계 조건은 까다롭다. 특히 1m급의 고해상도 영상을 얻기 위해서는 개념설계 단계에서부터 여러 가지 기술적인 면과 운용적인 면을 동시에 고려해야 하며 이러한 조건들이 상호 연관성을 가지면서 광학계의 형태나 성능을 결정하므로 다양한 해석과 분석이 필요하다. 해상도, 촬영고도, 관측폭 그리고 촬영소자의 크기에 의해 광학계의 초점거리가 결정되며 광학계의 유효구경을 추가하면 신호량 성능에 대한 예측이 가능하다. (중략)

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Optimization of Abdominal X-ray Images using Generative Adversarial Network to Realize Minimized Radiation Dose (방사선 조사선량의 최소화를 위한 생성적 적대 신경망을 활용한 복부 엑스선 영상 최적화 연구)

  • Sangwoo Kim;Jae-Dong Rhim
    • Journal of the Korean Society of Radiology
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    • v.17 no.2
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    • pp.191-199
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    • 2023
  • This study aimed to propose minimized radiation doses with an optimized abdomen x-ray image, which realizes a Deep Blind Image Super-Resolution Generative adversarial network (BSRGAN) technique. Entrance surface doses (ESD) measured were collected by changing exposure conditions. In the identical exposures, abdominal images were acquired and were processed with the BSRGAN. The images reconstructed by the BSRGAN were compared to a reference image with 80 kVp and 320 mA, which was evaluated by mean squared error (MSE), peak signal-to-noise ratio (PSNR), and structural similarity index measure (SSIM). In addition, signal profile analysis was employed to validate the effect of the images reconstructed by the BSRGAN. The exposure conditions with the lowest MSE (about 0.285) were shown in 90 kVp, 125 mA and 100 kVp, 100 mA, which decreased the ESD in about 52 to 53% reduction), exhibiting PSNR = 37.694 and SSIM = 0.999. The signal intensity variations in the optimized conditions rather decreased than that of the reference image. This means that the optimized exposure conditions would obtain reasonable image quality with a substantial decrease of the radiation dose, indicating it could sufficiently reflect the concept of As Low As Reasonably Achievable (ALARA) as the principle of radiation protection.