1. A method for obtaining extended field of view diagnostic ultrasound images, the method comprising: acquiring first and second image frames of the object of interest, wherein the first and second image frames are rotated relative to one another; identifying pixel points in the first image frame representative of spatial points in said object of interest; computing pixel points in the second image frame corresponding to said pixel points in the first image frame; calculating a rotation angle between the first image frame and the second image frame based upon a least-squares relation between said pixel points in the first and second image frames; and combining the first and second image frames based on the rotation angle to form an extended field of view image.