Pgmabel User Manual(0) Pgmabel User Manual(0)
NAME
pgmabel - create cross section using Abel Integration for Deconvolution
SYNOPSIS
pgmabel [-help] [-axis axis] [-factor factor] [-pixsize pixsize] [-left
| -right] [-verbose] [filespec]
You can abbreviate any option to its shortest unique prefix.
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 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
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*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.
OPTIONS
-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 center of the image.
-factor factor
User defined factor for enhancement of the output. Use a factor
less than 1 for decreasing 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@voyager.boerde.de)
Copyright (C) 1997-2002 German Aerospace research establishment
netpbm documentation June 2002 Pgmabel User Manual(0)
