segfind#
- astropop.photometry.segfind(data, threshold, background, noise, mask=None, fwhm=None, npix=5, deblend=True)#
Find sources using
segmentation
.- Parameters:
- data: array_like
2D array containing the image to extract the sources.
- threshold: `int` or `float`
Minumim number of standard deviations above the background level where the algorithm will start to consider the sources.
- background: `float` or `~numpy.ndarray`
Background level estimation. Can be a single global value, or a 2D array with by-pixel values.
- noise: `float` or `~numpy.ndarray`
RMS or any other noise estimation to use in the detection. Can be a single global value, or a 2D array with by-pixel values.
- mask: array_like (optional)
Boolean mask where 1 pixels are masked out in the background calculation. Default:
None
- fwhm: `float` (optional)
FWHM to generate the convolution kernel. If
None
, no convolution will be performed. Default:None
- npix: `int` (optional)
Minimum number of connected pixels to consider a source. Default:
5
- deblend: `bool` (optional)
If
True
, the algorithm will try to deblend the sources. Default:True
- Returns:
- sources:
astropy.table.Table
Table with the sources found. The table will contain the following columns: -
id
: source ID -x
,y
: x and y coordinates of the source centroid -xcentroid
,ycentroid
: same asx
andy
-peak
: value of the source peak -flux
: integrated (background-subtracted) source flux within thesegment
sigma_x
,sigma_y
: standard deviation of the source elipsoid along x and ytheta
: rotation angle of the source elipsoid (degrees) from the positive x axisfwhm
: FWHM of circular gaussian fit of the sourceeccentricity
: The eccentricity of the 2D Gaussian function that has the same second-order moments as the source.elongation
: The ratio of the lengths of the semimajor and semiminor axes.ellipticity
: 1.0 minus the elongation.cxx
,cyy
,cxy
: SourceExtractor ellipse parameters. See [SourceExtractor docs]_area
: area of the segment, in pixelslabel
: label identifying the segment to which the source belongs. Can be used as y-sorted index.
- sources:
References