A Geometric Method for Subpixel Boundary

A new geometric method is presented for sub-pixel boundary extraction. Many existing methods can obtain boundary pixels, so this paper tries to locate accurately the object edge inside a pixel. Assuming that the boundary is straight line at a pixel size, the new method analyzes the neighboring pixels blurred by the boundary, and finds the boundary by a geometric method. It is proved that the result is accurate for the straight boundary edge. In addition, the new method is proved not to be sensitive to noise. Examples are given to compare the new method and interpolation method at last.