Estimating the displacements of intensity patterns between sequential frames is a very well-studied problem, which is usually referred to as optical flow estimation. The first assumption among many of the methods in the field is the brightness constancy during movements of pixels between frames. This assumption is proven to be not true in general, and therefore, the use of photometric invariant...

The dilute-to-dense transition of granular flow of particle size d(0) is studied experimentally in a two-dimensional channel (width D) with confined exit (width d). Our results show that with fixed d and D there is a maximum inflow rate Q(c) above which the flow changes from dilute to dense and the outflow rate drops abruptly from Q(c) to a dense rate Q(d). A rescaled critical rate q(c) ...

Pedestrians implicitly cooperate by forming lanes inside dense crowd in order to facilitate flow and prevent complete passage blocking. Our aim is to re-enforce this self-organization phenomenon in dense crowd for the purpose of virtual crowd animation and navigation simplification. The mechanism of a flow grid is introduced to measure flow over an area. The flow grid is a perception mechanism ...