Subpixel image registration using circular fiducials

The design of fiducials for precise image registration is of major practical importance in computer vision, especially in automatic inspection applications. The authors analyze the subpixel registration accuracy that can, and cannot, be achieved by some rotation-invariant fiducials, and present and analyze efficient algorithms for the registration procedure. They rely on some old and new results from lattice geometry and number theory and efficient computational-geometric algorithms.<>