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:



       o      Angular Second Moment

       o      Contrast

       o      Correlation

       o      Variance

       o      Inverse Difference Moment

       o      Sum Average

       o      Sum Variance

       o      Sum Entropy

       o      Entropy

       o      Difference Variance

       o      Difference Entropy

       o      Information Measures of Correlation

       o      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 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(5) , 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)