A More Robust Method for Digital Video Camera Calibration for Luminance Estimation
2022-01-0968
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. 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. Previous work has shown that pixel intensity captured by consumer-grade digital still cameras can be calibrated to estimate luminance. Taking a digital still image and converting this image into a luminance map even further reduces the time required for luminance measurement. Suway and Suway previously presented a methodology for estimating luminance from digital images and video of a scene. In this paper, the authors update this methodology for calculating luminance from a digital video camera. The updated calibration method results in more accurate luminance estimation over the entire range of the camera’s sensor, particularly in low-light conditions. Further refinements to the fitting methodology result in a robust calibration even in the presence of measurement noise. Ultimately, 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.
- Citation
- Suway, J., and Suway, S., "A More Robust Method for Digital Video Camera Calibration for Luminance Estimation," SAE Technical Paper 2022-01-0968, 2022, .