tweakreg_catalog module provides functions for generating catalogs
of sources from images.
make_tweakreg_catalog(model, kernel_fwhm, snr_threshold, sharplo=0.2, sharphi=1.0, roundlo=- 1.0, roundhi=1.0, brightest=None, peakmax=None)¶
Create a catalog of point-line sources to be used for image alignment in tweakreg.
ImageModel) – The input
ImageModelof a single image. The input image is assumed to be background subtracted.
kernel_fwhm (float) – The full-width at half-maximum (FWHM) of the 2D Gaussian kernel used to filter the image before thresholding. Filtering the image will smooth the noise and maximize detectability of objects with a shape similar to the kernel.
snr_threshold (float) – The signal-to-noise ratio per pixel above the
backgroundfor which to consider a pixel as possibly being part of a source.
sharplo (float, optional) – The lower bound on sharpness for object detection.
sharphi (float, optional) – The upper bound on sharpness for object detection.
roundlo (float, optional) – The lower bound on roundess for object detection.
roundhi (float, optional) – The upper bound on roundess for object detection.
Maximum peak pixel value in an object. Only objects whose peak pixel values are strictly smaller than
peakmaxwill be selected. This may be used to exclude saturated sources. By default, when
peakmaxis set to
None, all objects will be selected.
DAOStarFinderautomatically excludes objects whose peak pixel values are negative. Therefore, setting
peakmaxto a non-positive value would result in exclusion of all objects.
catalog – An astropy Table containing the source catalog.
- Return type