RGB Images¶
- hostphot.rgb_images.linear(inputArray, scale_min=None, scale_max=None)¶
Performs linear scaling of the input numpy array.
- Parameters
inputArray (numpy array) – Image data array.
scale_min (float, default
None
) – Minimum data value.scale_max (float, default
None
) – Maximum data value.
- Returns
imageData – Scaled image data array.
- Return type
numpy array
- hostphot.rgb_images.sqrt(inputArray, scale_min=None, scale_max=None)¶
Performs
sqrt()
scaling of the input numpy array.- Parameters
inputArray (numpy array) – Image data array.
scale_min (float, default
None
) – Minimum data value.scale_max (float, default
None
) – Maximum data value.
- Returns
imageData – Scaled image data array.
- Return type
numpy array
- hostphot.rgb_images.log(inputArray, scale_min=None, scale_max=None)¶
Performs
log10()
scaling of the input numpy array.- Parameters
inputArray (numpy array) – Image data array.
scale_min (float, default
None
) – Minimum data value.scale_max (float, default
None
) – Maximum data value.
- Returns
imageData – Scaled image data array.
- Return type
numpy array
- hostphot.rgb_images.asinh(inputArray, scale_min=None, scale_max=None, non_linear=2.0)¶
Performs
asinh()
scaling of the input numpy array.- Parameters
inputArray (numpy array) – Image data array.
scale_min (float, default
None
) – Minimum data value.scale_max (float, default
None
) – Maximum data value.non_linear (float, default
2.0
) – Non-linearity factor.
- Returns
imageData – Scaled image data array.
- Return type
numpy array
- hostphot.rgb_images.create_RGB_image(outfile=None, survey='PS1', filters='zir', images_dir='', scaling='linear', scaling_params=None)¶
Creates an RGB image.
- Parameters
outfile (str, default
None
) – Output file name. If None, no output is saved.survey (str, default
PS1
) – Survey used for the filters.filters (str, defaul
zir
) – Filters used to create the RGB image (in that order). Must be three filters.images_dir (str, default ‘’) – Directory where to find the images.
scaling (str) – Type of scaling. Choose between
linear
,sqrt
,log
andasinh
.scaling_params (dict) – Dictionary with the parameters for the
scaling
function. IfNone
, use the default values.
Examples
>>> # Example of scaling_params: >>> scaling_params = {'R':{'min':r_med/100, 'max':r_med*30}, 'G':{'min':g_med/1000, 'max':g_med*150}, 'B':{'min':b_med/30, 'max':b_med*100}}
- hostphot.rgb_images.get_PS1_url(ra, dec, size=3, filters='grizy', data_format='jpg')¶
Get URL for the colour image.
- Parameters
ra (float) – Right Ascension in degrees.
dec (float) – Declination in degrees.
size (float or ~astropy.units.Quantity, default
3
) – Image size. If a float is given, the units are assumed to be arcmin.filters (str) – Filters to include.
data_format (str) – Data format (options are
jpg
orpng
).
- Returns
url – The image’s URL for a colour image.
- Return type
str
- hostphot.rgb_images.get_PS1_RGB_image(outfile, ra, dec, size=3, filters='grizy')¶
Downloads an RGB image from the PS1 server.
- Parameters
outfile (str) – URL of the image to be downloaded
ra (float) – Right Ascension in degrees.
dec (float) – Declination in degrees.
size (float or ~astropy.units.Quantity, default
3
) – Image size. If a float is given, the units are assumed to be arcmin.filters (str) – Filters to include.
- Returns
url – The image’s URL for a colour image.
- Return type
str
- hostphot.rgb_images.get_SDSS_RGB_image(outfile, ra, dec, size=3)¶
Downloads an RGB image from the SDSS server.
- Parameters
remote_url (str) – URL of the image to be downloaded
ra (float) – Right Ascension in degrees.
dec (float) – Declination in degrees.
size (float or ~astropy.units.Quantity, default
3
) – Image size. If a float is given, the units are assumed to be arcmin.
- Returns
url – The image’s URL for a colour image.
- Return type
str