pgmtexture

Updated: 22 Aug 1991
Table Of Contents

NAME

pgmtexture - calculate textural features on a PGM image

SYNOPSIS

pgmtexture [-d d] [pgmfile]

DESCRIPTION

This program is part of Netpbm.

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.