COMPUTER ASSISTED FIELD ASSESSMENT OF TRANSPORTATION LIGHTING SYSTEMS WITH THE IQCAM~(TM) DIGITAL PHOTOMETRIC IMAGE ANALYSIS SYSTEM

摘要

We describe the IQCam~(TM) Digital Image Analysis System, which consists of a tripod-mounted custom 'medium resolution' digital camera (array size=500 pixels horizontal by 300 pixels vertical) with a parallel interface to a powerful laptop workstation, accessories and fullfeatured software. The system is capable of making photometric measurements on entire scenes and can capture the full dynamic range of a scene or object of interest automatically in a matter of a few seconds. Data obtained during the measurement process as well as quantitative description and analysis of the entire image and arbitrarily shaped objects within it is performed with easy-to-use software. This information can be saved to memory and/or printed in a variety of preformatted reports. The IQCam~(TM) system can be configured to be fully field portable. In the field system both the camera and computer operate on either line voltage or batteries. The camera can be powered by rechargeable C cells, alkaline C cells, line voltage or 12vdc from an automobile cigarette lighter. The entire field portable system fits into a carry-on case and can be set up in less than 5 minutes. Complex photometric measurements in field settings are possible down to luminance levels of about 1 candela per metre squared. Calibration tests with the system show that it is linear over a nearly 50 dB dynamic range.