Cross Correlation between instantaneous images

This tool is used to execute cross-correlation between two images taken during a PIV experiment.

Our aim is to study two images, one at instant t and the second at instant t+dt where dt is an extremely small time interval. These smaller sections are called windows. Now, the next step is to further study these windows separately and analyze where this window would fir into the bigger picture at the next instant. If we could locate the location of this small window with respect to the image taken after time dt, we can get the displacement of the particles with time by calculating the distance between the center point of these two windows. So rather than studying each particle separately or the entire image as a whole, we divide the image into smaller windows and relate these windows with the image taken at the next instant and get the displacement. Now, we do the same thing for the other windows as well. That’s the basic logic behind the cross-correlation tool.