• Title/Summary/Keyword: camera exposure

Search Result 166, Processing Time 0.02 seconds

The effects of virtual reality-based physical therapy in stroke patients

  • Kim, Charyong;Min, Won-Kyu
    • Physical Therapy Rehabilitation Science
    • /
    • v.2 no.1
    • /
    • pp.7-11
    • /
    • 2013
  • Objective: Final goal of nerve advancement therapy is to provide maximum ability to function independently in life to patients. This paper appraises and describes basic concepts of the virtual reality (VR) based exercise program to improve functional movement for neurologically impaired patients. Design: Review article. Methods: Stroke patients from the physical therapy department while wearing comfortable clothing receive therapy and also VR based motion therapy administered by the therapist in charge. After evaluation of stroke patients, therapy includes an exercise program that is suitable for use with stroke patients; stroke patients wear head-mounted display while in front of the computer, where the camera is located; they follow the action on the screen and the computer perceives the operation of the stroke patients according to subject accomplishment. Results: According to obstacle condition of stroke patients using the method, which is various environments after setting, in stroke patients, there is a possibility of presenting suitable therapeutic environments. The display presentation of the method, which is identical, causes difficulty for all stroke patients. According to subject accomplishment; stroke patients result in execution of repetition training and deepening study, which leads to mobility. Conclusions: The VR based rehabilitation training programs is a difference of the existing video training program, is immediate feedback and compensation method. It will provide rehabilitation training services for the family of the patient whose condition could be improved with rehabilitative therapy where it is a continuous circumstance as a matter of the social welfare facility therapy.

  • PDF

The Implementation of 3D Measurement System by Image Pointing Method (영상선점 기법에 의한 3차원 측위 시스템 구현)

  • 송승호;김용배;주영은;엄대용
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.20 no.2
    • /
    • pp.191-197
    • /
    • 2002
  • Recently, with the eye-opening progress in the related field of computer, the development of high resolution digital camera enables more precise positioning in digital photogrammetry, and a lot of interest has been concentrated on its application. In this study, the algorithm and system which enable the measurement of 3D point more easily was developed by image pointing method using digital image, when the digital map of the Cultural Properties of Architectures in Modern Ages is drawn by photogrammetry. As a result, we can reduce the limitation of surveying control point, exposure condition, and construct the digital map and 3D model of architecture more efficiently.

Anomaly detection of isolating switch based on single shot multibox detector and improved frame differencing

  • Duan, Yuanfeng;Zhu, Qi;Zhang, Hongmei;Wei, Wei;Yun, Chung Bang
    • Smart Structures and Systems
    • /
    • v.28 no.6
    • /
    • pp.811-825
    • /
    • 2021
  • High-voltage isolating switches play a paramount role in ensuring the safety of power supply systems. However, their exposure to outdoor environmental conditions may cause serious physical defects, which may result in great risk to power supply systems and society. Image processing-based methods have been used for anomaly detection. However, their accuracy is affected by numerous uncertainties due to manually extracted features, which makes the anomaly detection of isolating switches still challenging. In this paper, a vision-based anomaly detection method for isolating switches, which uses the rotational angle of the switch system for more accurate and direct anomaly detection with the help of deep learning (DL) and image processing methods (Single Shot Multibox Detector (SSD), improved frame differencing method, and Hough transform), is proposed. The SSD is a deep learning method for object classification and localization. In addition, an improved frame differencing method is introduced for better feature extraction and a hough transform method is adopted for rotational angle calculation. A number of experiments are conducted for anomaly detection of single and multiple switches using video frames. The results of the experiments demonstrate that the SSD outperforms the You-Only-Look-Once network. The effectiveness and robustness of the proposed method have been proven under various conditions, such as different illumination and camera locations using 96 videos from the experiments.

Auto-Exposure Control using Loop-Up Table Based on Scene-Luminance Curve in Mobile Phone Camera (입.출력 특성곡선에 기초한 Look-Up Table 방식의 자동노출제어)

  • Lee, Tae-Hyoug;Kyung, Wang-Jun;Lee, Cheol Hee;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.47 no.4
    • /
    • pp.56-62
    • /
    • 2010
  • Auto-exposure control automatically calculates and adjusts the exposure for consecutive input image. Recently, this is usually controlled by the sensor gain, however, unsuitable control causes oscillation of luminance for sonsecutive input images, called as flickering. Also, in mobile phone cameras, only simple information, such as the average luminance value, can be utilized due to coarse performance. Therefore, this paper presents a new real-time AE control method using a Look Up Table(LUT) based on Scene-Luminance curves to avoid the generation of flickering. Prior to the AE control, a LUT is constructed, which illustrates the characteristic of outputs for input patches corresponding to sensor gains. The AE control is first performed by estimating a current scene as a patch using the proposed LUT. A new sensor gain is then estimated using also LUT with previously estimated patch. The entire estimation process is performed using linear interpolation to achieve real-time execution. Based on experimental results, the proposed AE control is demonstrated with real-time, flicker-free.

Multi-spectral Flash Imaging using Region-based Weight Map (영역기반 가중치 맵을 이용한 멀티스팩트럼 플래시 영상 획득)

  • Choi, Bong-Seok;Kim, Dae-Chul;Lee, Cheol-Hee;Ha, Yeong-Ho
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.50 no.9
    • /
    • pp.127-135
    • /
    • 2013
  • In order to acquire images in low-light environments, it is usually necessary to adopt long exposure times or resort to flash lights. However, flashes often induce color distortion, cause the red-eye effect and can be disturbing to subjects. On the other hand, long-exposure shots are susceptible to subject-motion, as well as motion-blur due to camera shake when performed hand-held. A recently introduced technique to overcome the limitations of traditional low-light photography is that of multi-spectral flash. Multi-spectral flash images are a combination of UV/IR and visible spectrum information. The general idea is that of retrieving details from the UV/IR spectrum and color from the visible spectrum. However, multi-spectral flash images themselves are subject to color distortion and noise. This works presents a method to compute multi-spectral flash images so that noise can be reduced and color accuracy improved. The proposed approach is a previously seen optimization method, improved by the introduction of a weight map used to discriminate uniform regions from detail regions. The weight map is generated by applying canny edge operator and it is applied to the optimization process for discriminating the weights in uniform region and edge. Accordingly, the weight of color information is increased in the uniform region and the detail region of weight is decreased in detail region. Therefore, the proposed method can be enhancing color reproduction and removing artifacts. The performance of the proposed method has been objectively evaluated using long-exposure shots as reference.

An Optimization Method of Measuring Heart Position in Dynamic Myocardial Perfusion SPECT with a CZT-based camera (동적 심근관류 SPECT에서 심장의 위치 측정방법에 대한 고찰)

  • Seong, Ji Hye;Lee, Dong Hun;Kim, Eun Hye;Jung, Woo Young
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.23 no.1
    • /
    • pp.75-79
    • /
    • 2019
  • Purpose Cadmium-zinc-telluride (CZT) camera with semiconductor detector is capable of dynamic myocardial perfusion SPECT for coronary flow reserve (CFR). Image acquisition with the heart positioned within 2 cm in the center of the quality field of view (QFOV) is recommended because the CZT detector based on focused multi-pinhole collimators and is stationary gantry without rotation. The aim of this study was to investigate the optimal method for measuring position of the heart within the center of the QFOV when performing dynamic myocardial perfusion SPECT with the Discovery NM 530c camera. Materials and Methods From June to September 2018, 45 patients were subject to dynamic myocardial perfusion SPECT with D530c. For accurate heart positioning, the patient's heart was scanned with a mobile ultrasound and marked at the top of the probe where the mitral valve (MV) was visible in the parasternal long-axis view (PLAX). And, the marked point on the patient's body matched with the reference point indicated CZT detector in dynamic stress. The heart was positioned to be in the center of the QFOV in rest. The coordinates of dynamic stress and rest were compared statistically. Results The coordinates of the dynamic stress using mobile ultrasound and those taken of the rest were recorded for comparative analysis with regard to the position of the couch and analyzed. There were no statistically significant differences in the coordinates of Table in & out, Table up & down, and Detector in & out (P > 0.05). The difference in distance between the 2 groups was measured at $0.25{\pm}1.00$, $0.24{\pm}0.96$ and $0.25{\pm}0.82cm$ respectively, with no difference greater than 2 cm in all categories. Conclusion The position of the heart taken using mobile ultrasound did not differ significantly from that of the center of the QFOV. Therefore, The use of mobile ultrasound in dynamic stress will help to select the correct position of the heart, which will be effective in clinical diagnosis by minimizing the image quality improvement and the patient's exposure to radiation.

A New Algorithm for the Interpretation of Joint Orientation Using Multistage Convergent Photographing Technique (수렴다중촬영기법을 이용한 새로운 절리방향 해석방법)

  • 김재동;김종훈
    • Tunnel and Underground Space
    • /
    • v.13 no.6
    • /
    • pp.486-494
    • /
    • 2003
  • When the orientations of joints are measured on a rock exposure, there are frequent cases that are difficult to approach by the surveyor to the target joints or to set up scanlines on the slope. In this study, to complement such limit and weak points, a new algorithm was developed to interpret joint orientation from analyzing the images of rock slope. As a method of arranging the multiple images of a rock slope, the multistage convergent photographing system was introduced to overcome the limitation of photographing direction which existing method such as parallel stereophotogrammetric system has and to cover the range of image measurement, which is the overlapping area between the image pair, to a maximum extent. To determine camera parameters in the perspective projection equation that are the main elements of the analysis method, a new method was developed introducing three ground control points and single ground guide point. This method could be considered to be very simple compared with other existing methods using a number of ground control points and complicated analysis process. So the global coordinates of a specific point on a rock slope could be analyzed with this new method. The orientation of a joint could be calculated using the normal vector of the joint surface which can be derived from the global coordinates of several points on the joint surface analyzed from the images.

15×15 Kernel Block Adaptive Median Filter based on LED Illumination Detection Algorithm for Low Rate CamCom (15×15 Kernel Block Adaptive Median Filter를 적용한 저속 카메라 통신용 LED 조명 검출 알고리즘 연구)

  • Han, Jungdo;Lee, Minwoo;Cha, Jae Sang
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.17 no.5
    • /
    • pp.143-150
    • /
    • 2018
  • With the rapid development of RF based high speed wireless communication technology, devices that can be applied to IoT networks based on RF bandwidth are rapidly spreading, nevertheless, the development speed of the RF communication is not possible to keep up with the spread of the RF band for wireless communication. In this situation, OWC technology that uses visible light source as a transmitter is attracting attention as a technology that can overcome the band exhaustion problem of RF based wireless communication technology. Although, due to the distortion of the LED illumination shape by camera exposure time and LED blinking period, the LED illumination detection rate is degraded and the RoI setting is inaccurate. In this paper, we propose an adaptive median filter applied LED illumination detection algorithm for low rate CamCom, it is possible to detect a clear RoI and LED illumination. This research will be able to play a role as a complementary material of RF based wireless communication technology efficiently.

Generation of Mosaic Image using Aerial Oblique Images (경사사진을 이용한 모자이크 영상 제작)

  • Seo, Sang Il;Park, Byung-Wook;Lee, Byoung Kil;Kim, Jong In
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.22 no.3
    • /
    • pp.145-154
    • /
    • 2014
  • The road network becomes more complex and extensive. Therefore, the inconveniences are caused in accordance with the time delay of the restoration of damaged roads, demands for excessive costs on information collection, and limitations on acquisition of damage information of the roads. Recently, road centric spatial information is gathered using mobile multi sensor system for road inventory. But expensive MMS(Mobile Mapping System) equipments require high maintenance costs from beginning and takes a lot of time in the data processing. So research is needed for continuous maintenance by collecting and displaying the damaged information on a digital map using low cost mobile camera system. In this research we aim to develop the techniques for mosaic with a regular ground sample distance using successive image from oblique camera on a vehicle. For doing this, mosaic image is generated by estimating the homography of high resolution oblique image, and the ground sample distance and appropriate overlap are analyzed using high resolution aerial oblique images which contain resolution target. Based on this we have proposed the appropriate overlap and exposure interval for mobile road inventory system.

A Study on the Geometric Deformation Measurement of Structures by Collinearity Condition (공선조건에 의한 구조물의 기하학적 변형해석에 관한 연구)

  • 강준묵;오원진;이진덕;한승희
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.4 no.2
    • /
    • pp.77-87
    • /
    • 1986
  • As for the deformation measurement of structure, there are many controversial points in using the methods by the strain guage, inclinometer, bial guage, and geodetic method because of the difficulty of instrument setting and the problem in the degree of accuracy of the results as well as in the economical aspect. Therefore, to verify the superiority of the Close- Range Photogrammetry method for the structural deformation measurement, the result of load deformation on the model structure, which was made using the Close-Range Photogrammetry method was compard with the results which was made using the methods of dial guage, precision level, and triangulation. In addition to that, to consider the general problem which would happen when C. R. P method was applied to the practical structure. The elements of C. R. P method like camera rotation angle ($\psi$,$\omega$), exposure elevation (Z$_{L}$), and angle of inclined base line ($\theta$) were experimented, and their specificities were reconsidered. As a result, the application of C. R. P method to the general structure is expected to be increased not only in the aspect of accuracy but in the economical aspect.t.

  • PDF