pgmabel [-help] [-axis axis] [-factor factor] [-pixsize pixsize]
[-left | -right] [-verbose] [filespec]
This program is part of Netpbm.
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 ver-
tical 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
After integration, pgmabel weights all gray-values of one side by the
surface area of the calculated ring in square pixels divided by 4*fac-
tor multiplied by the size of one pixel (pixsize). With the -verbose
option, pgmabel prints the weighting factors.
Where the caculation generates a negative result, the output is black.
The computation is unstable against periodic structures with size 2 in
the vertical direction.
You can abbreviate any option to its shortest unique prefix.
-help Prints a help message.
-left Calculate only the left side of the image. You cannot specify
-right Analogous to -left.
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
This program was added to Netpbm in Release 10.3 (June 2002).
Volker Schmidt (firstname.lastname@example.org)
Copyright (C) 1997-2002 German Aerospace research establishment