Some New Methods of Detecting Step Edges in Digital Pictures

This note describes two operators that respond
to step edges, but not to ramps.  The first 
is similar to the digital Laplacian, but uses the max, rather
than the sum, of the x and y second differences. 
 The second uses the difference between the mean and
median gray levels in a neighborhood.  The outputs 
obtained from these operators applied to a set of test
pictures are compared with each other and with 
the standard digital Laplacian and gradient.  A third
operator, which uses the distance between the center 
and centroid of a neighborhood as an edge value, is also
briefly considered; it turns out to be equivalent 
to one of the standard digital approximations to the gradient.

CACM February,1978

Schachter, B.
Rosenfeld, A.

image processing, pattern recognition, edge detection

3.63

CA780210 JB March 28, 1978  1:56 PM

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