sourcextractor.config.measurement_images.MeasurementImage Class Reference

Inheritance diagram for sourcextractor.config.measurement_images.MeasurementImage:

Collaboration diagram for sourcextractor.config.measurement_images.MeasurementImage:

Public Member Functions
def	__init__ (self, fits_file, psf_file=None, weight_file=None, gain=None, gain_keyword='GAIN', saturation=None, saturation_keyword='SATURATE', flux_scale=None, flux_scale_keyword='FLXSCALE', weight_type='none', weight_absolute=False, weight_scaling=1., weight_threshold=None, constant_background=None, image_hdu=1, psf_hdu=None, weight_hdu=None)
def	__str__ (self)

Public Attributes
	meta
	gain
	saturation
	flux_scale
	weight_type
	weight_absolute
	weight_scaling
	has_weight_threshold
	weight_threshold
	is_background_constant
	constant_background_value
	image_hdu
	psf_hdu
	weight_hdu

Private Member Functions
def	_load_header_file (self, filename, hdu)

Detailed Description

A MeasurementImage is the processing unit for SourceXtractor++. Measurements and model fitting can be done
over one, or many, of them. It models the image, plus its associated weight file, PSF, etc.

Parameters
----------
fits_file : str or astropy.fits.HDUList
    The path to a FITS image, or an instance of astropy.fits.HDUList
psf_file : str
    The path to a PSF. It can be either a FITS image, or a PSFEx model.
weight_file : str or astropy.fits.HDUList
    The path to a FITS image with the pixel weights, or an instance of astropy.fits.HDUList
gain : float
    Image gain. If None, `gain_keyword` will be used instead.
gain_keyword : str
    Keyword for the header containing the gain.
saturation : float
    Saturation value. If None, `saturation_keyword` will be used instead.
saturation_keyword : str
    Keyword for the header containing the saturation value.
flux_scale : float
    Flux scaling. Each pixel value will be multiplied by this. If None, `flux_scale_keyword` will be used
    instead.
flux_scale_keyword : str
    Keyword for the header containing the flux scaling.
weight_type : str
    The type of the weight image. It must be one of:

        - none
            The image itself is used to compute internally a constant variance (default)
        - background
            The image itself is used to compute internally a variance map
        - rms
            The weight image must contain a weight-map in units of absolute standard deviations
            (in ADUs per pixel).
        - variance
            The weight image must contain a weight-map in units of relative variance.
        - weight
            The weight image must contain a weight-map in units of relative weights. The data are converted
            to variance units.
weight_absolute : bool
    If False, the weight map will be scaled according to an absolute variance map built from the image itself.
weight_scaling : float
    Apply an scaling to the weight map.
weight_threshold : float
    Pixels with weights beyond this value are treated just like pixels discarded by the masking process.
constant_background : float
    If set a constant background of that value is assumed for the image instead of using automatic detection
image_hdu : int
    For multi-extension FITS file specifies the HDU number for the image. Default 1 (primary HDU)
psf_hdu : int
    For multi-extension FITS file specifies the HDU number for the psf. Defaults to the same value as image_hdu
weight_hdu : int
    For multi-extension FITS file specifies the HDU number for the weight. Defaults to the same value as image_hdu

Definition at line 37 of file measurement_images.py.

Constructor & Destructor Documentation

__init__()

def sourcextractor.config.measurement_images.MeasurementImage.__init__	(		self,
			fits_file,
			psf_file = None,
			weight_file = None,
			gain = None,
			gain_keyword = 'GAIN',
			saturation = None,
			saturation_keyword = 'SATURATE',
			flux_scale = None,
			flux_scale_keyword = 'FLXSCALE',
			weight_type = 'none',
			weight_absolute = False,
			weight_scaling = 1.,
			weight_threshold = None,
			constant_background = None,
			image_hdu = 1,
			psf_hdu = None,
			weight_hdu = None
	)

Constructor.

Definition at line 100 of file measurement_images.py.

Member Function Documentation

__str__()

def sourcextractor.config.measurement_images.MeasurementImage.__str__

(

self

)

Returns
-------
str
    Human readable representation for the object

Definition at line 206 of file measurement_images.py.

References std::locale::id.id(), std::thread::id.id(), SourceXtractor::PyId.id, sourcextractor.config.measurement_images.MeasurementImage.image_hdu, sourcextractor.config.measurement_images.MeasurementImage.meta, sourcextractor.config.measurement_images.MeasurementImage.psf_hdu, and sourcextractor.config.measurement_images.MeasurementImage.weight_hdu.

Here is the call graph for this function:

_load_header_file()

def sourcextractor.config.measurement_images.MeasurementImage._load_header_file (   self,   filename,   hdu  )

private

Definition at line 183 of file measurement_images.py.

References sourcextractor.config.measurement_images.MeasurementImage.meta.

Member Data Documentation

constant_background_value

sourcextractor.config.measurement_images.MeasurementImage.constant_background_value

Definition at line 162 of file measurement_images.py.

flux_scale

sourcextractor.config.measurement_images.MeasurementImage.flux_scale

Definition at line 145 of file measurement_images.py.

gain

sourcextractor.config.measurement_images.MeasurementImage.gain

Definition at line 131 of file measurement_images.py.

has_weight_threshold

sourcextractor.config.measurement_images.MeasurementImage.has_weight_threshold

Definition at line 155 of file measurement_images.py.

image_hdu

sourcextractor.config.measurement_images.MeasurementImage.image_hdu

Definition at line 167 of file measurement_images.py.

Referenced by sourcextractor.config.measurement_images.MeasurementImage.__str__().

is_background_constant

sourcextractor.config.measurement_images.MeasurementImage.is_background_constant

Definition at line 161 of file measurement_images.py.

meta

sourcextractor.config.measurement_images.MeasurementImage.meta

Definition at line 121 of file measurement_images.py.

Referenced by sourcextractor.config.measurement_images.MeasurementImage.__str__(), and sourcextractor.config.measurement_images.MeasurementImage._load_header_file().

psf_hdu

sourcextractor.config.measurement_images.MeasurementImage.psf_hdu

Definition at line 170 of file measurement_images.py.

Referenced by sourcextractor.config.measurement_images.MeasurementImage.__str__().

saturation

sourcextractor.config.measurement_images.MeasurementImage.saturation

Definition at line 138 of file measurement_images.py.

weight_absolute

sourcextractor.config.measurement_images.MeasurementImage.weight_absolute

Definition at line 152 of file measurement_images.py.

weight_hdu

sourcextractor.config.measurement_images.MeasurementImage.weight_hdu

Definition at line 175 of file measurement_images.py.

Referenced by sourcextractor.config.measurement_images.MeasurementImage.__str__().

weight_scaling

sourcextractor.config.measurement_images.MeasurementImage.weight_scaling

Definition at line 153 of file measurement_images.py.

weight_threshold

sourcextractor.config.measurement_images.MeasurementImage.weight_threshold

Definition at line 158 of file measurement_images.py.

weight_type

sourcextractor.config.measurement_images.MeasurementImage.weight_type

Definition at line 151 of file measurement_images.py.

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The documentation for this class was generated from the following file:

• SEImplementation/python/sourcextractor/config/measurement_images.py