An Application of Heuristic Search Methods to Edge and Contour Detection
This paper presents a method for detecting edges
and contours in noisy pictures.  The properties 
of an edge are embedded in a figure of merit and the edge
detection problem becomes the problem of minimizing 
the given figure of merit.  This problem can be represented
as a shortest path problem on a graph and 
can be solved using well-known graph search algorithms.
 The relations between this representation of 
the minimization problem and a dynamic programming approach
are discussed, showing that the graph search 
method can lead to substantial improvements in computing
time.  Moreover, if heuristic search methods 
are used, the computing time will depend on the amount
of noise in the picture.  Some experimental results 
are given; these show how various information about the
shape of the contour of an object can be embedded
in the figure of merit, thus allowing the extraction
of contours from noisy picture and the separation 
of touching objects.
CACM February, 1976
Martelli, A.
