pgmabel(1)

1Pgmabel User Manual(0)                                  Pgmabel User Manual(0)
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NAME

6       pgmabel - create cross section using Abel Integration for Deconvolution
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SYNOPSIS

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

15       This program is part of Netpbm(1).
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17       pgmabel reads as input a PGM image, which it assumes to be an image  of
18       a  rotational symmetric transparent object.  The image must have a ver‐
19       tical symmetry axis.  pgmabel produces as output an image of  a  cross-
20       section of the image.
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22       pgmabel does the calculation by performing the Abel Integration for De‐
23       convolution of an axial-symmetrical image by solving the system of lin‐
24       ear equations.
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26       After  integration,  pgmabel weights all gray-values of one side by the
27       surface area of the calculated ring in square pixels divided by  4*fac‐
28       tor  multiplied  by the size of one pixel (pixsize).  With the -verbose
29       option, pgmabel prints the weighting factors.
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31       Where the calculation generates a negative result, the output is black.
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33       The computation is unstable against periodic structures with size 2  in
34       the vertical direction.
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OPTIONS

38       In  addition  to  the options common to all programs based on libnetpbm
39       (most notably -quiet, see
40        Common Options ⟨index.html#commonoptions⟩ ),  pgmabel  recognizes  the
41       following command line options:
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43       You can abbreviate any option to its shortest unique prefix.
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48       -help  Prints a help message.
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51       -axis axis
52              Position of the axis of symmetry in the image in pixels from the
53              left edge of the image.  Default is the center of the image.
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56       -factor factor
57              User defined factor for enhancement of the output.  Use a factor
58              less than 1 for decreasing gary values.  Default is 1.0.
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61       -pixsize pixsize
62              The  size  of  a  pixel for getting scale invariant.  Default is
63              0.1.
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66       -left  Calculate only the left side of the image.  You  cannot  specify
67              both left and right.
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70       -right Analogous to -left.
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73       -verbose
74              print information about the calculation.
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EXAMPLE

80       Rotate  a  PGM  image to get an image with a vertical axis of symmetry,
81       then calculate the cross section:
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83           pnmrotate 90 file.pgm | pgmabel -axis 140 >cross_section.pgm
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HISTORY

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

96       Volker Schmidt (lefti@voyager.boerde.de)
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98       Copyright (C) 1997-2002 German Aerospace research establishment
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DOCUMENT SOURCE

101       This manual page was generated by the Netpbm tool 'makeman'  from  HTML
102       source.  The master documentation is at
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104              http://netpbm.sourceforge.net/doc/pgmabel.html
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106netpbm documentation               June 2002            Pgmabel User Manual(0)