Pgmabel User Manual(0) Pgmabel User Manual(0) 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 You can abbreviate any option to its shortest unique prefix. -help Prints a help message. -axis axis 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. -factor factor User defined factor for enhancement of the output. Use a factor less than 1 for decreasing gary values. Default is 1.0. -pixsize pixsize The size of a pixel for getting scale invariant. Default is 0.1. -left Calculate only the left side of the image. You cannot specify both left and right. -right Analogous to -left. -verbose 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(5) , 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 netpbm documentation June 2002 Pgmabel User Manual(0)