Image

class prose.Image

Object containing image data and metadata

When a FITS path (or header) is provided, keyword values are used to identify and instantiate a Telescope object. Image attributes then use this object to retrieve specific image information such as ra, dec, untis… etc

Parameters:

• fitspath (str or Path, optional) – file path , by default None

• data (numpy.ndarray, optional) – image data, by default None

• header (dict-like, optional) – image metadata, by default None

Example

from prose.tutorials import image_sample

# loading and showing an example image
image = image_sample("05 38 44.851", "+04 32 47.68")
image.show()

INFO Querying https://archive.stsci.edu/cgi-bin/dss_form

<Axes: >

image.header[0:10] # the 10 first lines

SIMPLE  =                    T /FITS: Compliance                                
BITPIX  =                   16 /FITS: I*2 Data                                  
NAXIS   =                    2 /FITS: 2-D Image Data                            
NAXIS1  =                  713 /FITS: X Dimension                               
NAXIS2  =                  714 /FITS: Y Dimension                               
EXTEND  =                    T /FITS: File can contain extensions               
DATE    = '2023-04-14        '  /FITS: Creation Date                            
ORIGIN  = 'STScI/MAST'         /GSSS: STScI Digitized Sky Survey                
SURVEY  = 'POSSI-O '           /GSSS: Sky Survey                                
REGION  = 'XO538   '           /GSSS: Region Name                               

Once this object is instantiated, its parameters are mapped to the ones of the telescope, detected from the header information. This exposes conveniant attributres, for example:

print(f"pixel scale : {image.pixel_scale:.2f}\nFOV: {image.fov}\nnight: {image.night_date}\n")

pixel scale : 1.01 arcsec
FOV: [0.20003263 0.20031318] deg
night: 1955-11-22

some of them being directly translated into astropy Quantity or datetime object.

Methods

__init__([fitspath, data, header, verbose, ...])	Object containing image data and metadata
copy([data])	Copy of image object
enough_stars([n, error])
from_telescope(telescope)
gaia_stars([world, inplace])	Query gaia stars in the image (only in >= 2.0.3)
get(key[, default])	Return corresponding value from header, similar to dict.get
has_stars([error])
plot_aperture(center[, arcmin])	Plot an aperture with radius defined in arcmin
plot_catalog(name[, color, label, n])	Plot catalog stars
plot_marks(coordinates[, label, ax])	Plot circular marks given world coordinates (only in >= 2.0.3)
plot_psf_model([cmap, c, figsize, axes])
plot_sources([ax])
show([cmap, ax, figsize, stars, zscale, ...])	Show image data
show_cutout([star, size])	Show a zoomed cutout around a detected star or coordinates
writeto(destination)

Attributes

airmass	Observation airmass as written in image header
bjd_tdb	BJD TDB time of the observation
date	datetime of the observation
dec	DEC of the image as written in header
exposure	Image exposure time in seconds
filter	Observation filter as written in image header
flip	Telescope flip as written in image header
fov	RA-DEC field of view of the image in degrees
jd_utc	JD UTC time of the observation
label	A conveniant {Telescope}_{Date}_{Object}_{Filter} string
night_date	date of the night when night started.
object
peaks
pixel_scale	Pixel scale (or plate scale) in arcseconds
plate_solved	Return whether the image is plate solved
ra	RA of the image as written in header
seeing	Seeing of the image as written is header
shape	Shape of the image data np.ndarray
skycoord	astropy SkyCoord object based on header RAn, DEC
stars_coords	Image sources pixel coordinates
wcs	astropy.wcs.WCS object associated with the FITS Image.header