pgmtexture

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 matrices at 0, 45, 90, and 135 degrees for a dis-
       tance 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  Cy-
       bertinetics, 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 limited.  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  Station,  employer
       for hire of James Darrell McCauley.

                                  22 Aug 1991                    pgmtexture(1)