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 crosssection of the image.
pgmabel does the calculation by performing the Abel Integration for Deconvolution of an axialsymmetrical image by solving the system of linear equations.
After integration, pgmabel weights all grayvalues 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 caculation generates a negative result, the output is black.
The computation is unstable against periodic structures with size 2 in the vertical direction.
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 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(5) ,
HISTORY
This program was added to Netpbm in Release 10.3 (June 2002).
AUTHOR
Volker Schmidt (lefti@voyager.boerde.de)
Copyright (C) 19972002 German Aerospace research establishment