pgmtexture(1) pgmtexture(1)
**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). Tex-
tural 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. Tex-
tural features for image classification. *IEEE* *Transac-*
*tions* *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 lim-
ited. 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 Sta-
tion, employer for hire of James Darrell McCauley.
22 Aug 1991 1