NAME¶
pgmtexture - calculate textural features on a portable graymap
SYNOPSIS¶
pgmtexture [
-d d] [
pgmfile]
DESCRIPTION¶
Reads a portable graymap as input. Calculates textural features based on spatial
dependence matrices at 0, 45, 90, and 135 degrees for a distance
d
(default = 1). Textural features include:
- (1) Angular Second Moment,
(2) Contrast,
(3) Correlation,
(4) Variance,
(5) Inverse Difference Moment,
(6) Sum Average,
(7) Sum Variance,
(8) Sum Entropy,
(9) Entropy,
(10) Difference Variance,
(11) Difference Entropy,
(12, 13) Information Measures of Correlation, and
(14) Maximal Correlation Coefficient.
Algorithm taken from:
Haralick, R.M., K. Shanmugam, and I. Dinstein. 1973. Textural features for image
classification.
IEEE Transactions on Systems, Man, and
Cybertinetics, SMC-3(6):610-621.
BUGS¶
The program can run incredibly slow for large images (larger than 64 x 64) and
command line options are limited. The method for finding (14) the maximal
correlation coefficient, which requires finding the second largest eigenvalue
of a matrix Q, does not always converge.
REFERENCES¶
IEEE Transactions on Systems, Man, and Cybertinetics,
SMC-3(6):610-621.
SEE ALSO¶
pgm(5),
pnmcut(1)
AUTHOR¶
Copyright (C) 1991 by Texas Agricultural Experiment Station, employer for hire
of James Darrell McCauley.