DOKK / manpages / debian 10 / montage / mSubimage.1.en
MSUBIMAGE(1) Montage MSUBIMAGE(1)

mSubimage - Create a "cutout" of a FITS image

mSubimage [-d] [-a] [-h hdu] [-s statusfile] in.fits out.fits ra dec xsize [ysize]

mSubimage -p [-d] [-h hdu] [-s statusfile] in.fits out.fits xstartpix ystartpix xpixsize [ypixsize]

Creates a subimage (or "cutout") of a FITS file. Note that in "normal" mode, all the parameters (location and size) are in degrees; in pixel (-p) mode, all of them are in pixels

Turns on debugging.
All pixels - Force retrieval of whole image (useful to extract an entire HDU)
Operate on the specified FITS header extension (HDU)
Output and errors are sent to statusfile instead of to stdout
Pixel mode - create subimage using pixel locations, instead of a location on the sky

Input FITS file.
Path to output FITS file.
In normal mode, RA of center of output image.
In normal mode, declination of center of output image.
In pixel mode, pixel along the x-axis where the cutout image will begin
In pixel mode, pixel along the y-axis where the cutout image will begin
In normal mode, width of output image in degrees.
In normal mode, height of output image in degrees (default is equal to xsize.
In pixel mode, width of output image in pixels
In pixel mode, height of output image in pixels (default is equal to xpixsize

[struct stat="OK", content="blank, flat or normal"]

The content keyword indicates whether all pixels where NaN (blank), all pixels were the same value (flat), or the image appears to be normal.

[struct stat="OK", content="blank, flat or normal"]
HDU value (hdu) must be a non-negative integer
Cannot open status file: statusfile
Center RA string (string) cannot be interpreted as a real number
Center Dec string (string) cannot be interpreted as a real number
X size string (string) cannot be interpreted as a real number
Y size string (string) cannot be interpreted as a real number
Invalid 'x' size
Invalid 'y' size
Image file filename missing or invalid FITS
Cannot find HDU hdu
Output wcsinit() failed.
Location is off image
Region outside image
No pixels match area.
Can't create output file: out.fits
FITS library error

$ mSubimage image1.fits subimage.fits 307.9 37.29 .01 .01
[struct stat="OK", content="normal"]

The drizzle algorithm has been implemented but has not been tested in this release.

If a header template contains carriage returns (i.e., created/modified on a Windows machine), the cfitsio library will be unable to read it properly, resulting in the error: [struct stat="ERROR", status=207, msg="illegal character in keyword"]

It is best for the background correction algorithms if the area described in the header template completely encloses all of the input images in their entirety. If parts of input images are "chopped off" by the header template, the background correction will be affected. We recommend you use an expanded header for the reprojection and background modeling steps, returning to the originally desired header size for the final coaddition. The default background matching assumes that there are no non-linear background variations in the individual images (and therefore in the overlap differences). If there is any uncertainty in this regard, it is safer to turn on the "level only" background matching (the "-l" flag in mBgModel.

2001-2015 California Institute of Technology, Pasadena, California

If your research uses Montage, please include the following acknowledgement: "This research made use of Montage. It is funded by the National Science Foundation under Grant Number ACI-1440620, and was previously funded by the National Aeronautics and Space Administration's Earth Science Technology Office, Computation Technologies Project, under Cooperative Agreement Number NCC5-626 between NASA and the California Institute of Technology."

The Montage distribution includes an adaptation of the MOPEX algorithm developed at the Spitzer Science Center.

Dec 2016 Montage 5