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
23       Deconvolution of an axial-symmetrical image by solving  the  system  of
24       linear 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 caculation 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       You can abbreviate any option to its shortest unique prefix.
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43       -help  Prints a help message.
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46       -axis axis
47              Position of the axis of symmetry in the image in pixels from the
48              left edge of the image.  Default is the center of the image.
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51       -factor factor
52              User defined factor for enhancement of the output.  Use a factor
53              less than 1 for decreasing gary values.  Default is 1.0.
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56       -pixsize pixsize
57              The  size  of  a  pixel for getting scale invariant.  Default is
58              0.1.
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61       -left  Calculate only the left side of the image.  You  cannot  specify
62              both left and right.
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65       -right Analogous to -left.
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68       -verbose
69              print information about the calculation.
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EXAMPLE

75       Rotate  a  PGM  image to get an image with a vertical axis of symmetry,
76       then calculate the cross section:
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78           pnmrotate 90 file.pgm | pgmabel -axis 140 >cross_section.pgm
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SEE ALSO

84       pnmrotate(1), pgm(1),
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HISTORY

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

92       Volker Schmidt (lefti@voyager.boerde.de)
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94       Copyright (C) 1997-2002 German Aerospace research establishment
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98netpbm documentation               June 2002            Pgmabel User Manual(0)
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