# pgmtexture

Pgmtexture User **Manual(0)** Pgmtexture User **Manual(0)**

## NAME

pgmtexture - calculate textural features on a PGM image

## SYNOPSIS

**pgmtexture**
[**-d** *d*]
[*pgmfile*]

## DESCRIPTION

This program is part of **Netpbm(1)**.
**pgmtexture** reads a PGM image as input and calculates textural features
based on spatial dependence matrices at 0, 45, 90, and 135 degrees for
a distance *d* (default = 1).
Textural features include:
· Angular Second Moment
· Contrast
· Correlation
· Variance
· Inverse Difference Moment
· Sum Average
· Sum Variance
· Sum Entropy
· Entropy
· Difference Variance
· Difference Entropy
· Information Measures of Correlation
· 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.*

## LIMITATIONS

The program can run incredibly slow for large images (larger than 64 x
64) and command line options are limited. The method for finding the
Maximal Correlation Coefficient, which requires finding the second
largest eigenvalue of a matrix Q, does not always converge.

## SEE ALSO

**pgm(1)**, **pamsharpness(1)**, **pamsharpmap(1)**, **pgmedge(1)**, **pgmminkowski(1)**

## AUTHOR

Copyright (C) 1991 by Texas Agricultural Experiment Station, employer
for hire of James Darrell McCauley.
netpbm documentation 22 Aug 1991 Pgmtexture User **Manual(0)**

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