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Pgmabel User Manual
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pgmabel
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Updated: June 2002
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Table Of Contents
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NAME
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pgmabel - create cross section using Abel Integration for Deconvolution
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SYNOPSIS
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\fBpgmabel\fR
[\fB-help\fR]
[\fB-axis\fR \fIaxis\fR]
[\fB-factor\fR \fIfactor\fR]
[\fB-pixsize\fR \fIpixsize\fR]
[\fB-left\fR | \fB-right\fR]
[\fB-verbose\fR]
[\fIfilespec\fR]
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You can abbreviate any option to its shortest unique prefix.
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DESCRIPTION
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This program is part of Netpbm.
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\fBpgmabel\fR 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.  \fBpgmabel\fR produces as output an image of
a cross-section of the image.
\fBpgmabel\fR does the calculation by performing the Abel Integration
for Deconvolution of an axial-symmetrical image by solving the system
of linear equations.
After integration, \fBpgmabel\fR weights all gray-values of one side
by the surface area of the calculated ring in square pixels divided by
4*\fIfactor\fR multiplied by the size of one pixel (\fIpixsize\fR).
With the \fB-verbose\fR option, \fBpgmabel\fR prints the weighting
factors.
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Where the caculation generates a negative result, the output is black.
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The computation is unstable against periodic structures with size 2 in
the vertical direction.
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OPTIONS
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.RS
.IP "\fB-help\fR"
Prints a help message.
.IP "\fB-axis\fR \fIaxis\fR"
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.
.IP "\fB-factor\fR \fIfactor\fR"
User defined factor for enhancement of the output.  Use a \fIfactor\fR
less than 1 for decreasing gary values.  Default is 1.0.
.IP "\fB-pixsize\fR \fIpixsize\fR"
The size of a pixel for getting scale invariant.  Default is 0.1.
.IP "\fB-left\fR"
Calculate only the left side of the image.  You cannot specify both
\fBleft\fR and \fBright\fR.
.IP "\fB-right\fR"
Analogous to \fB-left\fR.
.IP "\fB-verbose\fR"
print information about the calculation.
.RE
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EXAMPLE
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Rotate a PGM image to get an image with a vertical axis of symmetry,
then calculate the cross section:
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    pnmrotate 90 file.pgm | pgmabel -axis 140 >cross_section.pgm
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SEE ALSO
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\fBpnmrotate\fR,
\fBpgm\fR,
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HISTORY
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This program was added to Netpbm in Release 10.3 (June 2002).
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AUTHOR
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Volker Schmidt (lefti@voyager.boerde.de)
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Copyright (C) 1997-2002 German Aerospace research establishment
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Table Of Contents
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NAME
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SYNOPSIS
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DESCRIPTION
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OPTIONS
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EXAMPLE
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SEE ALSO
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HISTORY
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AUTHOR
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