The invention relates to a computerized method of profiling a shear flow, such as a boundary layer. The method includes receiving two successive images of a plurality of particles in the shear flow near the interface being analyzed. The method also includes determining a set of potential particle motion vectors based on the received images and dynamically ranks the likelihood that the potential tracks are correct based on track density. Track density is calculated using a plot matrix and kernel technique. The ranking is used to match particles from the successive images. The method also includes generating a velocity profile of the flow about the interface based on the particles matches and the determined location of the interface. The method is also applicable to moving and deforming interfaces.