Find Circular Edge Concepts

The Find Circular Edge step searches for a circular edge in a two-dimensional, annulus-shaped region of interest. The region of interest contains a number of search lines along which the step searches for sharp transitions in pixel intensities. A sharp transition typically characterizes the edge of an object in the image. The step fits a circle through the individual edge points of each search line to determine a circular edge on the object under inspection.

Note  The search lines extend radially in the region of interest.

For the best results, ensure that the region of interest encloses the entire edge that you want to find but excludes as many edges of no interest as possible. Make sure the edge fills up most of the region length. Also, make sure that the region is at least 20 pixels wide on either side of the edge to accurately detect the points along the edge.