Particle image velocimetry (PIV) is a method of imaging and analyzing field of flows. In the PIV method, small windows in an image of the field (time t) are compared with areas around the windows in the another image of the field (time t + Δt), and the most similar part to the windows are searched using two dimensional cross-correlation function. The computational complexity of the function is very huge, and can not be processed in real-time by micro-processors. In this paper, we describe a real-time visualization system for the PIV method. In the system, an improved direct computation method is used to reduce the computational complexity. The system consists of only one off-the-shelf Virtex-II FPGA board and a host computer, and calculates the complex function without reducing data bit-width, which becomes possible with one latest FPGA.
['Toshihito Fujiwara', 'K. Fujimoto', 'Tsutomu Maruyama']
A real-time visualization system for PIV