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A Method for Digital Video Camera Calibration for Luminance Estimation
Technical Paper
2017-01-1368
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Mapping the luminance values of a visual scene is of broad interest to accident reconstructionists, human factors professionals, and lighting experts. Such mappings are useful for a variety of purposes, including determining the effectiveness and appropriateness of lighting installations, and performing visibility analyses for accident case studies. One of the most common methods for mapping luminance is to use a spot type luminance meter. This requires individual measurements of all objects of interest and can be extremely time consuming. Luminance cameras can also be used to create a luminance map. While luminance cameras will map a scene’s luminance values more quickly than a spot luminance meter, commercially available luminance cameras typically require long capture times during low illuminance (up to 30 seconds). Previous work has shown that pixel intensity captured by consumer-grade digital still cameras can be calibrated to measure luminance. Taking a digital still image and converting this image into a luminance map even further reduces the measurement time. Regardless of whether one uses a digital still camera, luminance camera, or a spot type luminance meter, there is still the constraint that the user must be stationary in the scene for some period of time. This can be challenging if capturing a luminance map of an open roadway is desired, especially if the user will be capturing luminance from a driver’s perspective and location in a vehicle. In this paper, the authors present a methodology for calculating luminance from a digital video camera. The presented methodology allows for the user to mount a camera near the driver’s eye location and to drive through a scene capturing video. Still images from the video are then exported and analyzed, creating a luminance map. The resulting luminance estimates were compared to luminance values measured with a Konica Minolta LS-100 and our methods were shown to result in repeatable and accurate luminance measurements of an entire scene utilizing a quick, simple and safe capturing technique.
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Citation
Suway, J. and Suway, S., "A Method for Digital Video Camera Calibration for Luminance Estimation," SAE Technical Paper 2017-01-1368, 2017, https://doi.org/10.4271/2017-01-1368.Also In
References
- Moore , T. , Graves , H. , Perry , M. , Carter , D. Approximate field measurement of surface luminance using a digital camera Lighting Research and Technology March 2000 32 1 1 11
- Inanici , M. Evaluation of high dynamic range photography as a luminance data acquisition system Lighting Research and Technology June 2006 38 2 123 134
- Allin , B. , Ising , K. , and King , D. Digital Camera Calibration for Luminance Estimation in Nighttime Visibility Studies SAE Technical Paper 2007-01-0718 2007 10.4271/2007-01-0718
- Siegmann , P. Fundaments in Luminance and Retroreflectivity Measurements of Vertical Traffic Signs Using a Color Digital Camera IEEE Transactions on Instrumentation and Measurment 57 3 March 2008
- Bellia , L. , Spada , G. , Pedace , A. Lit environments quality: A software for the analysis of luminance maps obtained with a HDR imaging technique Energy and Buildings 67 December 2013 143 152
- Tural , E. , Tural , M. Luminance contrast analyses for low vision in a senior living facility: A proposal for an HDR image-based analysis tool Building and Environment 81 November 2014 20 28
- Efron , Bradley , and Tibshirani Robert An Introduction to the Bootstrap New York Chapman & Hall 1994
- Meyers , G. , Mooney , V. Measuring the Brightness of Streets by Means of Photography Illuminating Engineering 36 June 1941
- Marsh , C. , Marsh , E. A Photographic Method of Brightness Recording Illuminating Engineering 53 June 1958
- Lewin , L. , Bell. , W. Luminance Measurements by Photographic Photometry IES November 1968