Pgmabel User Manual(0) Pgmabel User Manual(0)

pgmabel - create cross section using Abel Integration for Deconvolution

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

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.

You can abbreviate any option to its shortest unique prefix.

Prints a help message.
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.
User defined factor for enhancement of the output. Use a factor less than 1 for decreasing gary values. Default is 1.0.
The size of a pixel for getting scale invariant. Default is 0.1.
Calculate only the left side of the image. You cannot specify both left and right.
Analogous to -left.
print information about the calculation.

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

pnmrotate(1) , pgm(5) ,

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

Volker Schmidt (

Copyright (C) 1997-2002 German Aerospace research establishment

June 2002 netpbm documentation