scholarly journals EVALUATION OF THE QUALITY OF ACTION CAMERAS WITH WIDE-ANGLE LENSES IN UAV PHOTOGRAMMETRY

2016 ◽  
Vol XLI-B1 ◽  
pp. 851-859 ◽  
Author(s):  
H. Hastedt ◽  
T. Ekkel ◽  
T. Luhmann
Keyword(s):  
Eye Lens ◽  
Experimental Setup ◽  
Light Weight ◽  
Wide Angle ◽  
Control Points ◽  
Wide Angle Lens ◽  
Standard Calibration ◽  
Normal Lens ◽  
Fish Eye

The application of light-weight cameras in UAV photogrammetry is required due to restrictions in payload. In general, consumer cameras with normal lens type are applied to a UAV system. The availability of action cameras, like the GoPro Hero4 Black, including a wide-angle lens (fish-eye lens) offers new perspectives in UAV projects. With these investigations, different calibration procedures for fish-eye lenses are evaluated in order to quantify their accuracy potential in UAV photogrammetry. Herewith the GoPro Hero4 is evaluated using different acquisition modes. It is investigated to which extent the standard calibration approaches in OpenCV or Agisoft PhotoScan/Lens can be applied to the evaluation processes in UAV photogrammetry. Therefore different calibration setups and processing procedures are assessed and discussed. Additionally a pre-correction of the initial distortion by GoPro Studio and its application to the photogrammetric purposes will be evaluated. An experimental setup with a set of control points and a prospective flight scenario is chosen to evaluate the processing results using Agisoft PhotoScan. Herewith it is analysed to which extent a pre-calibration and pre-correction of a GoPro Hero4 will reinforce the reliability and accuracy of a flight scenario.

scholarly journals EVALUATION OF THE QUALITY OF ACTION CAMERAS WITH WIDE-ANGLE LENSES IN UAV PHOTOGRAMMETRY

2016 ◽  
Vol XLI-B1 ◽  
pp. 851-859 ◽  
Author(s):  
H. Hastedt ◽  
T. Ekkel ◽  
T. Luhmann
Keyword(s):  
Eye Lens ◽  
Experimental Setup ◽  
Light Weight ◽  
Wide Angle ◽  
Control Points ◽  
Wide Angle Lens ◽  
Standard Calibration ◽  
Normal Lens ◽  
Fish Eye

The application of light-weight cameras in UAV photogrammetry is required due to restrictions in payload. In general, consumer cameras with normal lens type are applied to a UAV system. The availability of action cameras, like the GoPro Hero4 Black, including a wide-angle lens (fish-eye lens) offers new perspectives in UAV projects. With these investigations, different calibration procedures for fish-eye lenses are evaluated in order to quantify their accuracy potential in UAV photogrammetry. Herewith the GoPro Hero4 is evaluated using different acquisition modes. It is investigated to which extent the standard calibration approaches in OpenCV or Agisoft PhotoScan/Lens can be applied to the evaluation processes in UAV photogrammetry. Therefore different calibration setups and processing procedures are assessed and discussed. Additionally a pre-correction of the initial distortion by GoPro Studio and its application to the photogrammetric purposes will be evaluated. An experimental setup with a set of control points and a prospective flight scenario is chosen to evaluate the processing results using Agisoft PhotoScan. Herewith it is analysed to which extent a pre-calibration and pre-correction of a GoPro Hero4 will reinforce the reliability and accuracy of a flight scenario.

A Correction Method of Fish-Eye Lens Based on Projective Reconstruction

2014 ◽  
Vol 577 ◽  
pp. 741-744
Author(s):  
Jun Chao Zhu ◽  
Li Wan ◽  
Na Liu ◽  
Bao Feng Zhang
Keyword(s):  
Correction Method ◽  
Eye Lens ◽  
Wide Angle ◽  
Projective Reconstruction ◽  
Wide Angle Lens ◽  
Fish Eye

Fish-eye lens is a special wide angle lens shooting all of the information within 185 degrees at the same time, but the image taken by it cause distortion. In order to fit for people's visual habits, the images need a correction. This article proposes a correction method of fish-eye lens based on projective reconstruction and verified the effectiveness of the method by the experiment.

scholarly journals Partial Maxwell fish-eye lens inspired by Gutman lens and Eaton lens for wide-angle beam scanning

2021 ◽  
Author(s):  
Yong Liu ◽  
Hongda Lu ◽  
Zhipeng Liu ◽  
Yanbo Zhang ◽  
Ke Pang
Keyword(s):  
Eye Lens ◽  
Wide Angle ◽  
Beam Scanning ◽  
Fish Eye

Comparison of the Performance of the Calibration Algorithm of Wide-Angle Lens

2013 ◽  
Vol 467 ◽  
pp. 323-326
Author(s):  
Jong Eun Ha
Keyword(s):  
Visual Surveillance ◽  
Field Of View ◽  
Experimental Result ◽  
Eye Lens ◽  
Comparison Results ◽  
Calibration Algorithm ◽  
Wide Angle Lens ◽  
Present Experimental Result ◽  
Fish Eye ◽  
Small Field Of View

Fish-eye lens is used in various applications due to wide coverage of scene. In particular, it can be effectively used in visual surveillance and surround monitoring in automotive. It has large radial distortion compared to the conventional lens with small field of view. In this paper, we present comparison results for the calibration of fish-eye lens. We compare two algorithms where one is available in OpenCV [ and the other is Devernay and Faugeras [. Also, we present experimental result according to the number of calibration points, initialization value. We evaluate the accuracy of calibration thorough 3D reconstruction by stereo system. It can give more reliable evaluation than using reprojection eror by single camera.

scholarly journals Night sky quality monitoring in existing and planned dark sky parks by digital cameras

2017 ◽  
Vol 19 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Zoltán Kolláth ◽  
Anita Dömény
Keyword(s):  
Objective Measurement ◽  
Quality Monitoring ◽  
Wide Angle ◽  
Digital Cameras ◽  
Night Time ◽  
Mosaic Image ◽  
Wide Angle Lens ◽  
Night Sky ◽  
Crucial Part

A crucial part of the qualification of international dark sky places (IDSPs) is the objective measurement of night time sky luminance or radiance. Modern digital cameras provide an alternative way to perform all sky imaging either by a fisheye lens or by a mosaic image taken by a wide angle lens. Here we present a method for processing raw camera images to obtain calibrated measurements of sky quality. The comparison of the night sky quality of different European locations is also presented to demonstrate the use of our technique.

Optimum design of wide angle laser detecting system based on fish eye lens and sinusoidal amplitude grating

2014 ◽  
Vol 310 ◽  
pp. 173-178 ◽  
Author(s):  
Long Wang ◽  
Hongjun Dong ◽  
Weian Zhang ◽  
Xueju Shen
Keyword(s):  
Optimum Design ◽  
Eye Lens ◽  
Wide Angle ◽  
Fish Eye

Developmental Risk Through a Wide-Angle Lens

1987 ◽  
Vol 32 (1) ◽  
pp. 54-55
Author(s):  
Jack P. Shonkoff
Keyword(s):  
Wide Angle ◽  
Developmental Risk ◽  
Wide Angle Lens

scholarly journals Occlusion Culling for Wide-Angle Computer-Generated Holograms Using Phase Added Stereogram Technique

Photonics ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 298
Author(s):  
Juan Martinez-Carranza ◽  
Tomasz Kozacki ◽  
Rafał Kukołowicz ◽  
Maksymilian Chlipala ◽  
Moncy Sajeev Idicula
Keyword(s):  
Point Sources ◽  
Wide Angle ◽  
Computer Generated Holograms ◽  
Propagation Methods ◽  
Propagation Technique ◽  
3D Scene ◽  
Occlusion Culling ◽  
Fourier Type ◽  
Cloud Of Points

A computer-generated hologram (CGH) allows synthetizing view of 3D scene of real or virtual objects. Additionally, CGH with wide-angle view offers the possibility of having a 3D experience for large objects. An important feature to consider in the calculation of CGHs is occlusion between surfaces because it provides correct perception of encoded 3D scenes. Although there is a vast family of occlusion culling algorithms, none of these, at the best of our knowledge, consider occlusion when calculating CGHs with wide-angle view. For that reason, in this work we propose an occlusion culling algorithm for wide-angle CGHs that uses the Fourier-type phase added stereogram (PAS). It is shown that segmentation properties of the PAS can be used for setting efficient conditions for occlusion culling of hidden areas. The method is efficient because it enables processing of dense cloud of points. The investigated case has 24 million of point sources. Moreover, quality of the occluded wide-angle CGHs is tested by two propagation methods. The first propagation technique quantifies quality of point reproduction of calculated CGH, while the second method enables the quality assessment of the occlusion culling operation over an object of complex shape. Finally, the applicability of proposed occlusion PAS algorithm is tested by synthetizing wide-angle CGHs that are numerically and optically reconstructed.

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