thresOtsu
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Name
thresOtsu - threshold by the method of Otsu
Syntax
thresOtsu [-l <lpv>] [-h <hpv>] <inimage> [<outimage>]
Description
thresOtsu calculates, and eventually applies, the
threshold value by using the method of Otsu. The
method attempts to maximize the between-class variance
between the class of pixels above the threshold, and
the class of pixels below.
If an output image is given, the input image is
thresholded and written to the output image.
Otherwise the threshold value is only reported
to standard output.
Options
-
-l lpv
- Output for low pixels (below threshold). Default 0.
-
-h hpv
- Output for high pixels (above threshold). Default 255.
Reference
-
Otsu, N.
- "A Threshold Selection Method from Gray-Level histograms"
IEEE Trans. Syst., Man and Cyb.,
Vol SMC-9, No.1, pp.62-66.
See also
thresOtsu(3), threshold(1), thresPtile(1),
thresRidCal(1), thresLloyd(1)
Restrictions
inimage must have bands with pixel type unsigned byte.
Author
Tor Lønnestad, BLAB, Ifi, UiO
Examples
thresOtsu mona.img
thresOtsu -h 1 mona.img monaThres.img
Id
$Id: thresOtsu.c,v 1.20 1997/01/14 13:11:08 svein Exp $