Spectre: An Improved Phantom Edge Finder
Margaret M. Fleck · 1989
This paper describes an improved version of the Phantom edge finder, called Spectre. Spectre is simpler to implement, faster, and does more extensive image processing. The crucial topological sum operation is improved in two ways: a new tesselation for representing images simplifies sums along ID paths and a simpler, directional method is used to extend ID sums to 2D. Both edge finders use the topological sum to remove noise from second difference responses, so that zero-crossings in these responses represent reliable boundaries. Spectre applies the same techniques to a combination of first and third differences, producing a new map that reliably distinguishes real boundaries from spurious boundaries appearing in staircase intensity patterns. Similar processing is used to mark response regions not associated with zero-crossings (including