文章基本信息

标题：VISION SENSORS IN RAILWAY CLEARANCE MEASUREMENT SYSTEMS AND ANALYSIS OF THEIR SELECTION METHODS
其他标题：SENSORY WIZYJNE STOSOWANE W SYSTEMACH DO POMIARU SKRAJNI KOLEJOWEJ I ANALIZA METOD ICH DOBORU
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作者：Regina Tokarczyk ; Piotr Kohut ; Jakub Kolecki 等
期刊名称：Archiwum Fotogrametrii, Kartografii i Teledetekcji
印刷版ISSN：2083-2214
出版年度：2012
卷号：23
语种：English
出版社：Main Board of Association of Polish Surveyors
摘要：The characteristics of imagine systems used in railway clearance measurements can be divided into three groups: geometry of projection,radiometric quality and technical specifications. The geometry of image acquisition is determined in the camera calibration procedure. The interior orientation parameters of camera and distortion model parameters of a lens as well as an imaging sensor are estimated using special test-fields. The radiometric calibration and testing often involves the determination of the imaging system resolution,sharpness and contrast characteristics (MTF or SFR functions and gamma),dynamic range,noise and color projection accuracy. The process of image acquisition can be characterized by frequency and baud rate. The subsequent,widely used wire and wireless communication interfaces of currently used cameras are going to be compared: GiGE, CameraLink,USB,FireWire. The short deprecation of influence of applied interface on the baud rate,systems topology,wire lengths,processor load and the maximum number of connected imagine devices will be given. Within the conducted researches the few appropriate for the railway measurements cameras were tested. The examined cameras have various communication interfaces and were used with various lenses. The results of geometric calibration and radiometric testing will be given. The multi-variant camera calibration allowed to address the following problems: − what we can say about the quantitative characteristics of imagine errors depending on the lens used, − is the modeling of the radial distortion only sufficient and how many coefficients should be applied, − how big are the remaining residuals after applying the systematic image error corrections. The radiometric investigations was conducted using the IT8 and SFR Plus tests. The Imatest software was used. The most important features for the railway clearance measurements were examined,i.e. sharpness,contrast,dynamic range and color projection quality. As a result of conducted researches the set of important for the choice of imaging system features was determined.
其他摘要：Cechy charakterystyczne systemów wizyjnych stosowanych dla potrzeb pomiaru skrajni można podzielić na trzy grupy: opisujące geometrię odwzorowania,radiometrię i specyfikację techniczną kamery. Geometrię odwzorowania wyznacza się w procesie kalibracji kame
关键词：railway clearance;digital camera;camera calibration;radiometric calibration
其他关键词：skrajnia kolejowa;kamera cyfrowa;kalibracja kamery;radiometria kamery