A Multi-scale Based Algorithm for Sub-pixel Measurements of Circular Parts

A new sub-pixel edge detection algorithm based on multi-scale is introduced. Edge of the images is interpolated at different fuzzy scales. Positions obtained under different scales are interpolated further at the same position to obtain the sub-pixel edge. The sub-pixel edge is fitted to get the size of a circular which is measured at higher precision than traditional method. Validity of the algorithm has been testified by preliminary experiments and such algorithm can be applied to many kinds of precision parts´ size detection.