1.1.1.0 image.newimagefromfits

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image.newimagefromfits - Function

1.1.1 Construct a CASA image by conversion from a FITS image file
Description

This function is used to convert a FITS disk image file (Float, Double, Short, Long are supported) to an CASA image file. If outfile is given, the image is written to the specified disk file. If outfile is unset, the on-the-fly Image tool returned by this function is associated with a temporary image. This temporary image may be in memory or on disk, depending on its size. When you destroy the on-the-fly Image tool (with the done function) this temporary image is deleted.

This function reads from the FITS primary array (when the image is at the beginning of the FITS file; whichhdu=0), or an image extension (when the image is elsewhere in the FITS file, whichhdu > 0).

By default, any blanked pixels will be converted to a mask value which is false, and a pixel value that is NaN. If you set zeroblanks=T then the pixel value will be zero rather than NaN. The mask will still be set to false. See the function replacemaskedpixels if you need to replace masked pixel values after you have created the image.

Arguments


Inputs
outfile	Output image file name. Default is unset.
	allowed:	string
	Default:
infile	Input FITS disk file name. Required.
	allowed:	string
	Default:
whichrep	If this FITS file contains multiple coordinate representations, which one should we read
	allowed:	int
	Default:	0
whichhdu	If this FITS file contains multiple images, which one should we read (0-based).
	allowed:	int
	Default:	0
zeroblanks	If there are blanked pixels, set them to zero instead of NaN
	allowed:	bool
	Default:	false
overwrite	Overwrite (unprompted) pre-existing output file?
	allowed:	bool
	Default:	false

Returns
casaimage

Example

"""
#
print "\t----\t newimagefromfits Ex 1 \t----"
# Assume we can find test fits file using
# CASAPATH environment variable
pathname=os.environ.get("CASAPATH")
pathname=pathname.split()[0]
datapath=pathname+’/data/demo/Images/imagetestimage.fits’
im1=ia.newimagefromfits(’./myimage’, datapath, overwrite=true)
print im1.summary()
print im1.miscinfo()
print ’fields=’, im1.miscinfo().keys()
im1.done()
#
"""

The FITS image is converted to a CASA image file and access is provided via the image tool called im1. Any FITS header keywords which were not recognized or used are put in the miscellaneous information bucket accessible with the miscinfo function. In the example we list the names of the fields in this record.

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