---
name: "astcrop"
section: "1"
platform: "linux"
package: "gnuastro"
version: "0.23-2+b3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/astcrop"
---

# astcrop(1)

crop regions of a dataset

## NAME

Crop - crop regions of a dataset

## SYNOPSIS

**astcrop** \[*OPTION*...\] \[*Crop-Identifier*\] *ASTRdata* ...

## DESCRIPTION

Crop is part of GNU Astronomy Utilities 0.23. Crop will create cutouts, thumbnails, postage stamps or crops of region(s) from input image(s) using image or celestial coordinates. If muliple crops are desired, a catalog must be provided. When in WCS mode, if the cut out covers more than one input image, all overlapping input images will be stitched in the output.

For more information, please run any of the following commands. In particular the second contains a very comprehensive explanation of Crop's invocation: expected input(s), output(s), and a full description of all the options.

- All options and their values:

  $ astcrop **-P**

- Inputs/Outputs and options:

  $ info astcrop

- Full section in manual/book:

  $ info Crop

- 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`

Crop options:

-

  Input:

- **--hendwcs**=*INT*

  Header keyword number to stop reading WCS.

- **--hstartwcs**=*INT*

  Header keyword number to start reading WCS.

- **-h**, **--hdu**=*STR*/INT

  Extension name or number of (all) input(s).

- **-O**, **--mode**=*STR*

  Coordinate mode 'img' or 'wcs'.

- **-z**, **--zeroisnotblank**

  0\.0 in float or double images are not blank.

-

  Output:

- **-a**, **--metaname**=*STR*

  Name of output HDU (EXTNAME keyword in FITS).

- **-A**, **--append**

  If output exists, append crop to existing HDUs.

- **-b**, **--noblank**

  Remove parts of the crop box out of input image.

- **-D**, **--dontdelete**

  Don't delete output if it exists.

- **-K**, **--keepinputdir**

  Keep input directory for automatic output.

- **--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.

- **--primaryimghdu**

  Write crop in primary/zero-th HDU of output.

- **-p**, **--suffix**=*STR*

  Suffix (postfix) of cropped images.

- **--tableformat**=*STR*

  Table fmt: 'fits-ascii', 'fits-binary', 'txt'.

- **-t**, **--oneelemstdout**

  Print one element's value on stdout.

- **-T**, **--type**=*STR*

  Type of output: e.g., int16, float32, etc...

- **--wcslinearmatrix**=*STR*

  WCS linear matrix of output ('pc' or 'cd').

**-X**, **--widthinpix**           **--width** is in pixels (even in WCS mode).

-

  Crop by center

- **--checkcenter**=*FLT*/INT

  Width (in pixels) of box at center to check.

- **-c**, **--center**=*FLT\[*,...\]

  Central coordinates of a single crop.

- **-w**, **--width**=*FLT\[*,...\]

  Width when crop is defined by its center.

-

  Crop by center (when a catalog is given)

- **--cathdu**=*STR*/INT

  HDU of catalog, if it is a FITS table.

- **-C**, **--catalog**=*FITS*/TXT

  Input catalog filename.

- **-I**, **--ignorecase**

  Ignore case in matching/searching columns.

- **-n**, **--namecol**=*STR*/INT

  Column no./info of crop filename (no suffix).

- **--searchin**=*STR*

  Select column(s): 'name', 'unit', 'comment'.

- **-x**, **--coordcol**=*STR*/INT

  Column no./info containing coordinates.

-

  Crop by region

- **-l**, **--polygon**=*FLT*,FLT\[:...\]

  Polygon vertices, also a DS9 region file.

- **--polygonout**

  Keep the polygon's outside, mask the inside.

- **--polygonsort**

  Sort polygon vertices as counter-clockwise.

- **-s**, **--section**=*STR*

  Image section string specifying crop range.

-

  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.

- **--lastconfig**

  Do not parse any more configuration files.

- **--log**

  Information about output(s) in a log file.

- **--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 optional 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 © 2015-2024 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 **Crop** is maintained as a Texinfo manual.  If the **info** and **Crop** programs are properly installed at your site, the command

-

  **info Crop**

should give you access to the complete manual.