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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.

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.

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
June 2002 netpbm documentation