A Global Image Orientation Method of the Self-Rotating Pan-Tilt-Zoom Camera for Photogrammetric Applications

Pan-tilt-zoom (PTZ) cameras are widely used in surveillance systems due to their wide field of view and high resolutions. However, the lack of accurate orientation information limits their full utilization in photogrammetry. Therefore, for photogrammetric applications, the primary task for PTZ camer...

Full description

Saved in:
Bibliographic Details
Main Authors: T. Xiao, Q. Hu, J. Kang, Q. Zhang, Z. Ye, F. Deng
Format: Article
Language:English
Published: Copernicus Publications 2024-12-01
Series:The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Online Access:https://isprs-archives.copernicus.org/articles/XLVIII-2-W7-2024/177/2024/isprs-archives-XLVIII-2-W7-2024-177-2024.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1846126054947684352
author T. Xiao
Q. Hu
J. Kang
Q. Zhang
Z. Ye
F. Deng
author_facet T. Xiao
Q. Hu
J. Kang
Q. Zhang
Z. Ye
F. Deng
author_sort T. Xiao
collection DOAJ
description Pan-tilt-zoom (PTZ) cameras are widely used in surveillance systems due to their wide field of view and high resolutions. However, the lack of accurate orientation information limits their full utilization in photogrammetry. Therefore, for photogrammetric applications, the primary task for PTZ cameras is to achieve image orientation. Cameras mounted on gimbals can only self-rotate around the base, resulting in acquired images that are nearly purely rotated. Current conventional structure from motion (SfM) pipelines assume pixel parallax exists between matching correspondences and generate object points through 3D triangulation. Applying these methods to estimate the interior and exterior orientation parameters of images from a self-rotating PTZ camera is challenging. To address this issue, this paper employs the concept of global SfM and proposes an improved global image orientation method for the pure rotation motion of PTZ cameras. Initially, a subset of image pairs is selected for internal orientation, and the internal orientation parameters of the images are estimated. Subsequently, global external orientation is performed on all images to estimate their external orientation parameters. Finally, bundle adjustment of the collinearity equation without object points optimizes both the internal and external orientation parameters. Experiments on synthetic and real-scene datasets demonstrate the practicality and accuracy of this method. For synthetic datasets, the estimated focal length of our method deviates from the true value by within 1 pixel, and the mean location error of the principal points is 0.93 pixels. For real-scene datasets, the mean reprojection error of the checkpoints of our method is 2.72 pixels, with a maximum of 4.66 pixels. In contrast, Agisoft Metashape's mean reprojection error is 4.73 pixels, with a maximum reaching 8.06 pixels. This shows that our method can accurately determine the image orientation parameters of PTZ cameras and achieve higher accuracy compared to the popular commercial software Agisoft Metashape.
format Article
id doaj-art-5e7f081b641947d584f702c61d2cc84d
institution Kabale University
issn 1682-1750
2194-9034
language English
publishDate 2024-12-01
publisher Copernicus Publications
record_format Article
series The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
spelling doaj-art-5e7f081b641947d584f702c61d2cc84d2024-12-13T06:46:12ZengCopernicus PublicationsThe International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences1682-17502194-90342024-12-01XLVIII-2-W7-202417718210.5194/isprs-archives-XLVIII-2-W7-2024-177-2024A Global Image Orientation Method of the Self-Rotating Pan-Tilt-Zoom Camera for Photogrammetric ApplicationsT. Xiao0Q. Hu1J. Kang2Q. Zhang3Z. Ye4F. Deng5School of Computer Science, Hubei University of Technology, 430068 Wuhan, ChinaSchool of Computer Science, Hubei University of Technology, 430068 Wuhan, ChinaCollege of Geological Engineering and Geomatics, Chang’an University, 710054 Xi’an, ChinaSchool of Computer Science, Hubei University of Technology, 430068 Wuhan, ChinaSchool of Computer Science, Hubei University of Technology, 430068 Wuhan, ChinaSchool of Geodesy and Geomatics, Wuhan University, 430079 Wuhan, ChinaPan-tilt-zoom (PTZ) cameras are widely used in surveillance systems due to their wide field of view and high resolutions. However, the lack of accurate orientation information limits their full utilization in photogrammetry. Therefore, for photogrammetric applications, the primary task for PTZ cameras is to achieve image orientation. Cameras mounted on gimbals can only self-rotate around the base, resulting in acquired images that are nearly purely rotated. Current conventional structure from motion (SfM) pipelines assume pixel parallax exists between matching correspondences and generate object points through 3D triangulation. Applying these methods to estimate the interior and exterior orientation parameters of images from a self-rotating PTZ camera is challenging. To address this issue, this paper employs the concept of global SfM and proposes an improved global image orientation method for the pure rotation motion of PTZ cameras. Initially, a subset of image pairs is selected for internal orientation, and the internal orientation parameters of the images are estimated. Subsequently, global external orientation is performed on all images to estimate their external orientation parameters. Finally, bundle adjustment of the collinearity equation without object points optimizes both the internal and external orientation parameters. Experiments on synthetic and real-scene datasets demonstrate the practicality and accuracy of this method. For synthetic datasets, the estimated focal length of our method deviates from the true value by within 1 pixel, and the mean location error of the principal points is 0.93 pixels. For real-scene datasets, the mean reprojection error of the checkpoints of our method is 2.72 pixels, with a maximum of 4.66 pixels. In contrast, Agisoft Metashape's mean reprojection error is 4.73 pixels, with a maximum reaching 8.06 pixels. This shows that our method can accurately determine the image orientation parameters of PTZ cameras and achieve higher accuracy compared to the popular commercial software Agisoft Metashape.https://isprs-archives.copernicus.org/articles/XLVIII-2-W7-2024/177/2024/isprs-archives-XLVIII-2-W7-2024-177-2024.pdf
spellingShingle T. Xiao
Q. Hu
J. Kang
Q. Zhang
Z. Ye
F. Deng
A Global Image Orientation Method of the Self-Rotating Pan-Tilt-Zoom Camera for Photogrammetric Applications
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
title A Global Image Orientation Method of the Self-Rotating Pan-Tilt-Zoom Camera for Photogrammetric Applications
title_full A Global Image Orientation Method of the Self-Rotating Pan-Tilt-Zoom Camera for Photogrammetric Applications
title_fullStr A Global Image Orientation Method of the Self-Rotating Pan-Tilt-Zoom Camera for Photogrammetric Applications
title_full_unstemmed A Global Image Orientation Method of the Self-Rotating Pan-Tilt-Zoom Camera for Photogrammetric Applications
title_short A Global Image Orientation Method of the Self-Rotating Pan-Tilt-Zoom Camera for Photogrammetric Applications
title_sort global image orientation method of the self rotating pan tilt zoom camera for photogrammetric applications
url https://isprs-archives.copernicus.org/articles/XLVIII-2-W7-2024/177/2024/isprs-archives-XLVIII-2-W7-2024-177-2024.pdf
work_keys_str_mv AT txiao aglobalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications
AT qhu aglobalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications
AT jkang aglobalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications
AT qzhang aglobalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications
AT zye aglobalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications
AT fdeng aglobalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications
AT txiao globalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications
AT qhu globalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications
AT jkang globalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications
AT qzhang globalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications
AT zye globalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications
AT fdeng globalimageorientationmethodoftheselfrotatingpantiltzoomcameraforphotogrammetricapplications