文章基本信息

标题：Geometric Calibration Of Thermographic Cameras
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作者：T. Luhmann ; J. Ohm ; J. Piechel 等
期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2010
卷号：XXXVIII - Part 5
页码：411-416
出版社：Copernicus Publications
摘要：The paper gives an overview of thermal imaging sensors for photogrammetric close-range applications. In particular, it presents results of the geometric calibration of thermographic cameras as they are used for building inspection and material testing. Two different test fields have been designed providing point targets that are visible in the thermal spectral band of the cameras. Five different cameras have been investigated. Four of them have solid state sensors with pixel sizes between 25 and 40 μm. One camera is working in scanning mode. The lenses for thermographic cameras are made of Germanium. Conventional imaging configurations (typically 20 images) have been used for camera calibration. Standard parameters for principal distance, principal point, radial distortion, decentring distortion, affinity and shear have been introduced into the self-calibrating bundle adjustment. All measured points are introduced as weighted control points. Image coordinates have been measured either in the professional software package AICON 3D Studio (ellipse operators), or in the IAPG software system Stereomess (least-squares template matching). The calibration results differ significantly from camera to camera. All lenses show relatively large decentring distortion and deviations from orthogonality of the image coordinate axes. Using the plane test field with lamps, the average image precision is 3/10 th of a pixel while the 3D test field with circular reflecting targets results in imaging errors of 1/20 th pixel
关键词：Thermography; Thermal Imaging; Calibration; Accuracy; Application