9
Automatic
Thresholding: Otsu’s Method
Assumption: the histogram is bimodal
t
Method: find the threshold t that minimizes
the weighted sum of within-group variances
for the two groups that result from
separating
the gray tones at value t.
See text (at end of
Chapter 3) for the recurrence relations;
in practice, this
operator works very well for true bimodal
distributions and not
too badly for others.
Grp 1 Grp 2
