man > pgmabel

Pgmabel User Manual(1)                 General Commands Manual                Pgmabel User Manual(1)

NAME
       pgmabel - create cross section using Abel Integration for Deconvolution


SYNOPSIS
       pgmabel  [-help] [-axis axis] [-factor factor] [-pixsize pixsize] [-left | -right] [-verbose]
       [filespec]


DESCRIPTION
       This program is part of Netpbm(1).

       pgmabel reads as input a PGM image, which it assumes to be an image of a rotational symmetric
       transparent object.  The image must have a vertical symmetry axis.  pgmabel produces as  out‐
       put an image of a cross-section of the image.

       pgmabel  does  the calculation by performing the Abel Integration for Deconvolution of an ax‐
       ial-symmetrical image by solving the system of linear equations.

       After integration, pgmabel weights all gray-values of one side by the  surface  area  of  the
       calculated  ring  in  square  pixels  divided by 4*factor multiplied by the size of one pixel
       (pixsize).  With the -verbose option, pgmabel prints the weighting factors.

       Where the calculation generates a negative result, the output is black.

       The computation is unstable against periodic structures with size 2 in  the  vertical  direc‐
       tion.


OPTIONS
       In  addition  to  the options common to all programs based on libnetpbm (most notably -quiet,
       see  Common Options ), pgmabel recognizes the following command line options:

       You can abbreviate any option to its shortest unique prefix.




       -help  Prints a help message.


       -axis axis
              Position of the axis of symmetry in the image in pixels from the left edge of the  im‐
              age.  Default is the center of the image.


       -factor factor
              User  defined  factor for enhancement of the output.  Use a factor less than 1 for de‐
              creasing gary values.  Default is 1.0.


       -pixsize pixsize
              The size of a pixel for getting scale invariant.  Default is 0.1.


       -left  Calculate only the left side of the image.  You cannot specify both left and right.


       -right Analogous to -left.


       -verbose
              print information about the calculation.




EXAMPLE
       Rotate a PGM image to get an image with a vertical axis of symmetry, then calculate the cross
       section:

           pnmrotate 90 file.pgm | pgmabel -axis 140 >cross_section.pgm



SEE ALSO
       pnmrotate(1), pgm(1),


HISTORY
       This program was added to Netpbm in Release 10.3 (June 2002).


AUTHOR
       Volker Schmidt (lefti AT voyager.de)

       Copyright (C) 1997-2002 German Aerospace research establishment

DOCUMENT SOURCE
       This manual page was generated by the Netpbm tool 'makeman' from  HTML  source.   The  master
       documentation is at

              http://netpbm.sourceforge.net/doc/pgmabel.html

netpbm documentation                          June 2002                       Pgmabel User Manual(1)