1. A method of processing ultrasound data, comprising: receiving ultrasound data for a first ultrasound image, said first ultrasound image being represented as a first set of discrete pixels corresponding to positions of a region of interest; receiving ultrasound data for a second ultrasound image, said second ultrasound image being represented as a second set of discrete pixels corresponding to positions of said region of interest; generating a displacement map by minimizing a cost function using a dynamic programming procedure that identifies each of said first set of discrete pixels with a corresponding one of said second set of discrete pixels; refining said displacement map to obtain intermediate displacement values corresponding to positions between said discrete pixels based on minimizing a local approximation to said cost function; and calculating a physical property of said region of interest based on said displacement map.