FreeBSD Manual Pages
SEGMENT(1) User Commands SEGMENT(1) NAME Segment - segmentation based on signal structure SYNOPSIS astsegment [OPTION...] ASTRdata DESCRIPTION Segment is part of GNU Astronomy Utilities 0.24. Segment will segment an initially labeled region based on structure with the signal. It will first find true clumps (local maxima), estimate which ones have strong connec- tions, and then grow them to cover the full area of each detection. For more information, please run any of the following commands. In particu- lar the second contains a very comprehensive explanation of Segment's invo- cation: expected input(s), output(s), and a full description of all the op- tions. All options and their values: $ astsegment -P Inputs/Outputs and options: $ info astsegment Full section in manual/book: $ info Segment Full Gnuastro manual/book: $ info gnuastro If you couldn't find your answer in the manual, you can get direct help from experienced Gnuastro users and developers. For more information, please run: $ info help-gnuastro Segment options: Input: --chdu=STR HDU/extension of convolved image in file. --convolved=FITS Convolved image file to avoid convolution. --dhdu=STR HDU containing detection image. -d, --detection=FITS Filename of detection image (to segment). -h, --hdu=STR/INT HDU containing values (science image). --khdu=STR HDU containing kernel image. -k, --kernel=FITS Filename of kernel to convolve with input. --sky=STR/FLT Filename of Sky values image to subtract. --skyhdu=STR HDU containing Sky value to subtract. --std=STR/FLT Filename of Sky standard deviation. --stdhdu=STR HDU containing Sky standard deviation. --variance STD input is actually variance. Tessellation (tile grid): --checktiles Tile IDs in an image, the size of input. -F, --remainderfrac=FLT Fraction of remainder to split last tile. --interpmetric=STR Interpolation metric (radial, manhattan). --interpnumngb=INT No. of neighbors to use for interpolation. --interponlyblank Only interpolate over the blank tiles. -L, --largetilesize=INT[,INT] Sim. to --tilesize, but for larger tiles. -M, --numchannels=INT[,..] No. of channels in dim.s (FITS order). --oneelempertile Display 1 element/tile, not full input res. --workoverch Work (not tile) over channel edges. -Z, --tilesize=INT[,INT] Regular tile size on dim.s (FITS order). Output: -D, --dontdelete Don't delete output if it exists. -K, --keepinputdir Keep input directory for automatic output. --noobjects Finish with true clumps, don't create objects. --outfitsnocommit No Git commit in 0-th HDU of output FITS. --outfitsnoconfig No metadata in 0-th HDU of output FITS. --outfitsnodate No 'DATE' in 0-th HDU of output FITS. --outfitsnoversions No versions in 0-th HDU of output FITS. -o, --output=STR Output file name. --rawoutput Output contains only CLUMPS and/or OBJECTS HDUs. --tableformat=STR 'txt', 'fits-ascii', 'fits-binary'. --wcslinearmatrix=STR WCS linear matrix of output ('pc' or 'cd'). Segmentation: -B, --minskyfrac=FLT Min. fraction of undetected area in tile. --checksegmentation Store segmentation steps in a file. --checksn Save clump S/N values into a file. -c, --snquant=FLT S/N Quantile of true sky clumps. --grownclumps Save grown clumps instead of original. -G, --gthresh=FLT Multiple of STD to stop growing clumps. --minima Built internal clumps from minima. --minnumfalse=INT Minimum number for S/N estimation. -m, --snminarea=INT Minimum area of clumps for S/N estimation. -O, --objbordersn=FLT Min. S/N for grown clumps as one object. -s, --clumpsnthresh=FLT S/N threshold of true clumps. -v, --keepmaxnearriver Keep clumps with peak touching a river. -y, --minriverlength=INT Minimum len of useful grown clump rivers. Operating modes: -?, --help give this help list --checkconfig List all config files and variables read. --cite BibTeX citation for this program. --config=STR Read configuration file STR immediately. --config-prefix=STR Custom prefix of option names config files. -C, --continueaftercheck Continue processing after checks. --lastconfig Do not parse any more configuration files. --minmapsize=INT Min. bytes to avoid RAM automatically. -N, --numthreads=INT Number of CPU threads to use. --onlyversion=STR Only run if the program version is STR. -P, --printparams Print parameter values to be used and abort. --quietmmap Don't print mmap'd file's name and size. -q, --quiet Only report errors, remain quiet about steps. -S, --setdirconf Set default values for this directory and abort. --usage give a short usage message -U, --setusrconf Set default values for this user and abort. -V, --version print program version Mandatory or optional arguments to long options are also mandatory or op- tional for any corresponding short options. GNU Astronomy Utilities home page: http://www.gnu.org/software/gnuastro/ REPORTING BUGS Report bugs to bug-gnuastro@gnu.org. COPYRIGHT Copyright (C) 2015-2025 Free Software Foundation, Inc. License GPLv3+: GNU General public license version 3 or later. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written/developed by Mohammad Akhlaghi SEE ALSO The full documentation for Segment is maintained as a Texinfo manual. If the info and Segment programs are properly installed at your site, the com- mand info Segment should give you access to the complete manual. GNU Astronomy Utilities 0.24 November 2025 SEGMENT(1)
NAME | SYNOPSIS | DESCRIPTION | REPORTING BUGS | COPYRIGHT | SEE ALSO
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=astsegment&sektion=1&manpath=FreeBSD+Ports+15.1.quarterly>