Camera calibration for water-biota research: the projected area of vegetation
Rene Wackrow
Edgar Ferreira
Jim Chandler
Koji Shiono
2134/19825
https://repository.lboro.ac.uk/articles/journal_contribution/Camera_calibration_for_water-biota_research_the_projected_area_of_vegetation/9450164
Imaging systems have an indisputable role in revealing vegetation posture under diverse flow conditions, image sequences being generated with off the shelf digital cameras. Such sensors are cheap but introduce a range of distortion effects, a trait only marginally tackled in hydraulic studies focusing on water-vegetation dependencies. This paper aims to bridge this gap by presenting a simple calibration method to remove both camera lens distortion and refractive effects of water. The effectiveness of the method is illustrated using the variable projected area, computed for both simple and complex shaped objects. Results demonstrate the significance of correcting images using a combined lens distortion and refraction model, prior to determining projected areas and further data analysis. Use of this technique is expected to increase data reliability for future work on vegetated channels.
2015-12-11 11:24:08
Photogrammetry
Underwater imaging
Eco-hydraulics
Flow visualization and imaging
Laboratory studies
Plants reconfiguration
Vegetated flows
Built Environment and Design not elsewhere classified
Ecology