make_catalog

petrofit.segmentation.make_catalog(image, threshold, wcs=None, deblend=True, npixels=None, nlevels=30, contrast=0.001, plot=True, vmax=None, vmin=None, figsize=None)[source]

This function constructs a catalog using PhotUtils. The petrofit.segmentation.make_segments and petrofit.segmentation.deblend_segments functions are used to construct segmentation maps and the resulting segmentation is turned into a vatalog (photutils.segmentation.catalog.SourceCatalog)

Parameters:
imagearray like

Input image.

thresholdfloat or array-like

The data value or pixel-wise data values to be used for the detection threshold. A 2D threshold must have the same shape as data. See detect_threshold for one way to create a threshold image.

wcsastropy.wcs.WCS

Astropy WCS for catalog to convert source locations to RA-Dec.

deblendbool

Flag to enable deblending of sources in the segmentation map.

npixelsint

The number of connected pixels, each greater than threshold, that an object must have to be detected. npixels must be a positive integer.

nlevelsint, optional

The number of multi-thresholding levels to use. Each source will be re-thresholded at nlevels levels spaced exponentially or linearly (see the mode keyword) between its minimum and maximum values within the source segment.

contrastfloat, optional

The fraction of the total (blended) source flux that a local peak must have (at any one of the multi-thresholds) to be considered as a separate object. contrast must be between 0 and 1, inclusive. If contrast = 0 then every local peak will be made a separate object (maximum deblending). If contrast = 1 then no deblending will occur. The default is 0.001, which will deblend sources with a 7.5 magnitude difference.

plotbool

Flag to toggle plotting segmentation maps.

vmin, vmaxfloat

vmax and vmin values for plot.

figsizetuple

Figure size.

Returns:
cat, segm, segm_deblend
catphotutils.segmentation.catalog.SourceCatalog

A catalog of sources

segmphotutils.segmentation.core.SegmentationImage

Segmentation map.

segm_deblendphotutils.segmentation.core.SegmentationImage

Deblended segmentation map.