\ .\" This man page was generated by the Netpbm tool 'makeman' from HTML source. .\" Do not hand-hack it! If you have bug fixes or improvements, please find .\" the corresponding HTML page on the Netpbm website, generate a patch .\" against that, and send it to the Netpbm maintainer. .TH "Pgmabel User Manual" 0 "June 2002" "netpbm documentation" .UN lbAB .SH NAME pgmabel - create cross section using Abel Integration for Deconvolution .UN lbAC .SH SYNOPSIS \fBpgmabel\fP [\fB-help\fP] [\fB-axis\fP \fIaxis\fP] [\fB-factor\fP \fIfactor\fP] [\fB-pixsize\fP \fIpixsize\fP] [\fB-left\fP | \fB-right\fP] [\fB-verbose\fP] [\fIfilespec\fP] .UN lbAD .SH DESCRIPTION .PP This program is part of .BR Netpbm (1) . .PP \fBpgmabel\fP 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\fP produces as output an image of a cross-section of the image. \fBpgmabel\fP 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\fP weights all gray-values of one side by the surface area of the calculated ring in square pixels divided by 4*\fIfactor\fP multiplied by the size of one pixel (\fIpixsize\fP). With the \fB-verbose\fP option, \fBpgmabel\fP prints the weighting factors. .PP Where the calculation generates a negative result, the output is black. .PP The computation is unstable against periodic structures with size 2 in the vertical direction. .UN lbAE .SH OPTIONS .PP You can abbreviate any option to its shortest unique prefix. .TP \fB-help\fP Prints a help message. .TP \fB-axis\fP \fIaxis\fP 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. .TP \fB-factor\fP \fIfactor\fP User defined factor for enhancement of the output. Use a \fIfactor\fP less than 1 for decreasing gary values. Default is 1.0. .TP \fB-pixsize\fP \fIpixsize\fP The size of a pixel for getting scale invariant. Default is 0.1. .TP \fB-left\fP Calculate only the left side of the image. You cannot specify both \fBleft\fP and \fBright\fP. .TP \fB-right\fP Analogous to \fB-left\fP. .TP \fB-verbose\fP print information about the calculation. .UN example .SH EXAMPLE .PP Rotate a PGM image to get an image with a vertical axis of symmetry, then calculate the cross section: .nf pnmrotate 90 file.pgm | pgmabel -axis 140 >cross_section.pgm .fi .UN lbAF .SH SEE ALSO .BR pnmrotate (1) , .BR pgm (5) , .UN history .SH HISTORY .PP This program was added to Netpbm in Release 10.3 (June 2002). .UN author .SH AUTHOR .PP Volker Schmidt (lefti@voyager.boerde.de) .PP Copyright (C) 1997-2002 German Aerospace research establishment