Manual: 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 output an image of a cross-section of the image.

       pgmabel does the calculation by performing the Abel Integration for Deconvolution of an	axial-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 direction.

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 image.	Default is the	cen‐
	      ter of the image.

       -factor factor
	      User  defined factor for enhancement of the output.  Use a factor less than 1 for decreasing gary values.	 De‐
	      fault 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@voyager.boerde.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)