A Cooperative Dual-Camera System for Face Recognition and Video Monitoring

2014 ◽  
Vol 998-999 ◽  
pp. 784-788 ◽  
Author(s):  
Zhuo Chen ◽  
Hai Bo Wu ◽  
Sheng Ping Xia

In the ordinary video monitoring system, the whole small scene is usually observed by a stationary camera or a few stationary cameras, but the system can’t zoom and focus on the target of interest rapidly, and also can’t get the high resolution image of the target of interest in a far distance. Therefore based on the research of the dual-camera cooperation and a RSOM clustering tree and CSHG algorithm, a cooperative dual-camera system is designed to track and recognize a face quickly in a large-scale and far-distance scene in this paper, which is made up of a Stationary Wide Field of View (SWFV) camera and a Pan-Tilt-Zoom (PTZ) camera. In the meanwhile, the algorithm can ensure the real-time requirement.

2021 ◽  
Vol 41 (2) ◽  
pp. 0208002
Author(s):  
李江勇 Li Jiangyong ◽  
冯位欣 Feng Weixin ◽  
刘飞 Liu Fei ◽  
魏雅喆 Wei Yazhe ◽  
邵晓鹏 Shao Xiaopeng

2010 ◽  
Vol 9 (2) ◽  
pp. 31-37 ◽  
Author(s):  
Masahiko Ogawa ◽  
Kazunori Shidoji ◽  
Yuji Matsuki

A camera and monitor system that projects actual real-world images has yet to be developed due to the technical limitation that the existing cameras cannot simultaneously acquire high-resolution and wide-angle images. In this research, we try to resolve this issue by superimposing images; a method which is effective because the entire wide-angle image does not necessarily need to be of high resolution because of perceptual characteristics of the human visual system. First, we examined the minimum resolution required for the field of view, which indicated that a triple-resolution image where positions more than 20 and 40 deg from the center of the visual field were decreased to 25% and approximately 11% of the resolution of the gaze point, respectively, was perceived as similar to a completely high-resolution image. Next, we investigated whether the participants could distinguish between the original completely high-resolution image and processed images, which included triple-resolution, dual-resolution, and low-resolution images. Our results suggested that the participants could not differentiate between the triple-resolution image and the original image. Finally, we developed a stereoscopic camera system based on our results


2020 ◽  
Author(s):  
Florian Willomitzer ◽  
Prasanna Rangarajan ◽  
Fengqiang Li ◽  
Muralidhar Balaji ◽  
Marc Christensen ◽  
...  

Abstract The presence of a scattering medium in the imaging path between an object and an observer is known to severely limit the visual acuity of the imaging system. We present an approach to circumvent the deleterious effects of scattering, by exploiting spectral correlations in scattered wavefronts. Our Synthetic Wavelength Holography (SWH) method is able to recover a holographic representation of hidden targets with high resolution over a wide field of view. The complete object field is recorded in a snapshot-fashion, by monitoring the scattered light return in a small probe area. This unique combination of attributes opens up a plethora of new Non-Line-of-Sight imaging applications ranging from medical imaging and forensics, to early-warning navigation systems and reconnaissance. Adapting the findings of this work to other wave phenomena will help unlock a wider gamut of applications beyond those envisioned in this paper.


2020 ◽  
Vol 497 (3) ◽  
pp. 4000-4008
Author(s):  
Rongyu Sun ◽  
Shengxian Yu ◽  
Peng Jia ◽  
Changyin Zhao

ABSTRACT Telescopes with a small aperture and a wide field of view are widely used and play a significant role in large-scale state-of-the-art sky survey applications, such as transient detection and near-Earth object observations. However, owing to the specific defects caused by optical aberrations, the image quality and efficiency of source detection are affected. To achieve high-accuracy position measurements, an innovative technique is proposed. First, a large number of raw images are analysed using principal component analysis. Then, the effective point spread function is reconstructed, which reflects the state of the telescope and reveals the characteristics of the imaging process. Finally, based on the point spread function model, the centroids of star images are estimated iteratively. To test the efficiency and reliability of our algorithm, a large number of simulated images are produced, and a telescope with small aperture and wide field of view is utilized to acquire the raw images. The position measurement of sources is performed using our novel method and two other common methods on these data. Based on a comparison of the results, the improvement is investigated, and it is demonstrated that our proposed technique outperforms the others on position accuracy. We explore the limitations and potential gains that may be achieved by applying this technique to custom systems designed specifically for wide-field astronomical applications.


2019 ◽  
Vol 85 (11) ◽  
pp. 815-827 ◽  
Author(s):  
Mi Wang ◽  
Beibei Guo ◽  
Ying Zhu ◽  
Yufeng Cheng ◽  
Chenhui Nie

The Gaofen-1 (GF1) optical remote sensing satellite is the first in China's series of high-resolution civilian satellites and is equipped with four wide-field-of-view cameras. The cameras work together to obtain an image 800 km wide, with a resolution of 16 m, allowing GF1 to complete a global scan in four days. To achieve high-accuracy calibration of the wide-field-of-view cameras on GF1, the calibration field should have high resolution and broad coverage based on the traditional calibration method. In this study, a GF self-calibration scheme was developed. It uses partial reference calibration data covering the selected primary charge-coupled device to achieve high-accuracy calibration of the whole image. Based on the absolute constraint of the ground control points and the relative constraint of the tie points of stereoscopic images, we present two geometric calibration models based on paired stereoscopic images and three stereoscopic images for wide-field-of-view cameras on GF1, along with corresponding stepwise internal-parameter estimation methods. Our experimental results indicate that the internal relative accuracy can be guaranteed after calibration. This article provides a new approach that enables large-field-of-view optical satellites to achieve high-accuracy calibration based on partial calibration-field coverage.


2007 ◽  
Vol 364-366 ◽  
pp. 550-554
Author(s):  
Jun Chang ◽  
Zhi Cheng Weng ◽  
Yong Tian Wang ◽  
De Wen Cheng ◽  
Hui Lin Jiang

In this paper, we are presenting a design method and its results for a space optical system with high resolution and wide field of view. This optical system can be used both in infrared and visible configurations. The designing of this system is based on an on-axis three-mirror anastigmatic (TMA) system. Here the on-axis concept allows wide field of view (FOV) enabling a diversity of designs available for the Multi-Object Spectrometer instruments optimized for low scattered and low emissive light. The available FOVs are upto 1º in both spectrum ranges, whereas the available aperture range is F/15 - F/10. The final optical system is a three-mirror telescope with two on-axis and one off-axis segment and its resolution is 0.3m or even lower. The distinguished feature of this design is that it maintains diffraction-limited image at wide wavelengths. The technological developments in the field of computer generated shaping of large-sized optical surface details with diffraction-limited imagery have opened new avenues towards the designing techniques. Such techniques permit us to expand these technological opportunities to fabricate the aspherical off-axis mirrors for a complex configuration.


2002 ◽  
Vol 2 (10) ◽  
pp. 134-134
Author(s):  
R. W. Massof ◽  
L. Brown ◽  
M. D. Shapiro ◽  
G. D. Barnett ◽  
F. H. Baker

2006 ◽  
Vol 18 (6) ◽  
pp. 787-794
Author(s):  
Xiaodong Tao ◽  
◽  
Hyungsuck Cho ◽  
Youngjun Cho ◽  

Vision techniques used in automatic microassembly are limited by inherent problems such as small depth of focus and small field of view. Microassembly must, however, initially detect microparts in a wide field of view and large depth of field while maintaining high resolution. We propose microassembly using active zooming that can overcome these limitations. For a small field of view, active zooming prevents the target from getting out of the field of view during microassembly. For a small depth of focus, our proposal is based on focus measure to maintain clear target image in the field of view during microassembly. Two-step assembly thus ensures zoom microscopy maintaining a wide field of view and large depth of field initially and high resolution at the end. Peg-in-hole assembly experiments confirmed the feasibility of our proposal.


Author(s):  
K. Ogura ◽  
J. Teshima

Observation of extremely thin insulating layers of silicon oxide and silicon nitride formed on a trench with a conventional EE SEM cannot be satisfactorily carried out by the conventional method to mechanically polish and chemically etch the wafer cross section and then investigate the state of layer formation from the uncvenness appearing on the cross section. One reason is that the resolution of the conventional FE SEM is not enough for the observation of several nm thick layers even if they arc etched. Another reason is that true layer thickness may be obscured by chemical etching. Those are why TEMs have been used for the observation of extremely thin insulating layers on trenches with atomic resolution. However, TEM application includes complicated specimen preparation, and does not allow observation of wide field of view. Therefore, the ultra-high resolution SEM (UHR SEM) has recently been used for similar purposes, using a simply cleaved plane of a wafer.


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