pgmtexture(1)                           General Commands Manual                           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 ma‐
       trices 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 op‐
       tions are limited.  The method for finding (14) the maximal correlation coefficient,  which  re‐
       quires 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.

                                              22 Aug 1991                                 pgmtexture(1)