Method and apparatus for sub-pixel edge detection

摘要

A method and apparatus for processing an image are disclosed. For edge detection, the zero crossing pixel location, n₀, within the image is identified. Then, a sub-pixel position offset, a, is determined. The offset is a relationship between interpolated image and an interpolated kernel at the zero crossing pixel location. Finally, the interpolated position for the edge location, t₀, is determined from the pixel location, n₀, and the sub-pixel position offset, a. For matching the detected edges of an object to edges of a model object, translation [v₁, v₂] between a detected edge of an object in the image and the corresponding edge of a model object is first determined. Next, cross correlation between the detected edge and the corresponding model edge is calculated. Then, translation error [e₁, e₂] is determined. Finally, the translation is updated.