ON IMAGE GRABBING AND PROCESSING FOR MEASUREMENT OF GEOPHYSICAL FLOWS

Image processing is nowadays widely used in laboratory and field measurements of several geophysical processes (e.g., flow field, sediment transport, dam-break flows, and so on). Thanks to a good compromise between large image resolution and memory storage at a relatively low price, the so-called action-cameras provide some advantages in comparison to industrial cameras and advanced vision systems. However, as the lens properties and key camera settings are imposed, pre-processing of the acquired images is necessary. In addition, commercial pre-processing software provided by the manufacturers is often based on default parameters that cannot be appropriately tuned, thus calling for codes to be developed ad hoc. This manuscript presents: (i) visualization experiments of bed-load sediment transport using action-cameras, (ii) a set of pre-processing tools to be applied to the grabbed images and (iii) proof-of-concept results for the statistics of particle kinematics. The findings presented here can be relevant for a variety of processes investigated experimentally.