Contours are useful to highlight the 2D shape of a certain flux level over an image. To derive contours in Statistics, you can use the option below:

`-R FLT[,FLT[,FLT...]]`¶`--contour=FLT[,FLT[,FLT...]]`-
Write the contours for the requested levels in a file ending with

`_contour.txt`. It will have three columns: the first two are the coordinates of each point and the third is the level it belongs to (one of the input values). Each disconnected contour region will be separated by a blank line. This is the requested format for adding contours with PGFPlots in LaTeX. If any other format can be useful for your work please let us know so we can add it. If the image has World Coordinate System information, the written coordinates will be in RA and Dec, otherwise, they will be in pixel coordinates.Note that currently, this is a very crude/simple implementation, please let us know if you find problematic situations so we can fix it.

GNU Astronomy Utilities 0.20 manual, April 2023.