A Comparison of Luminance Estimation Software to Measured Values
2022-01-0966
03/29/2022
- Event
- Content
- Mapping the luminance values of a visual scene is of broad interest to accident reconstructionists, human factors professionals, and lighting experts. Previous work has shown that pixel intensity captured by consumer-grade digital still cameras can be calibrated to estimate luminance. Suway and Suway presented a methodology for estimating luminance from digital images and video of a scene. This method requires the capture of dark images close in time to the capture of the image that will be used to estimate luminance. Additionally, Suway’s method requires the specific camera and lens combination used to be calibrated for luminance estimation. The methodology presented by Suway forms the basis for a software application, called Nitere, that calculates the relationship between pixel intensity and luminance for a camera lens combination and can therefore estimate real-world luminance values from pixel intensity for a properly calibrated camera and lens combination. In this paper, the authors compare the results of luminance values estimated through Nitere to the values as measured by a Westboro Photonics P501U imaging photometer system for a variety of cameras and across a wide range of luminous values. When properly calibrated, luminance values estimated with Nitere software is shown to compare favorably to those measured using an imaging photometer.
- Citation
- Carter, N., and Suway, J., "A Comparison of Luminance Estimation Software to Measured Values," SAE Technical Paper 2022-01-0966, 2022, .