[bug #62702] Clumps on strong gradients of larger galaxies become too large

[Mohammad Akhlaghi]

Follow-up Comment #4, bug #62702 (project gnuastro):

After some trials, in
[https://codeberg.org/gnuastro/gnuastro/commit/5c96952b53d commit
5c96952b53d], I discovered that a sufficiently robust method is to use the
variation of the azimuthal slice between subsequent pixels of a clump (as
opposed to cycles). 

In the image below, you can see an input image, and the resulting
over-segmented clumps ('DET_CLUMPS_ALL' in the output of
'--checksegmentation') between Gnuastro 0.20 and the commit above:

(file #55008)

During the false clump identification the two elongated clumps on top of the
good clump are rejected! Leaving us with a clean pixel map of only pixels that
are strongly affected by that clump and not the wing of the galaxy.

This task is not yet finished and some extra tests in the next steps of
segment (growth of true clumps in particular) are necessary.


    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?62702>

_______________________________________________
Message sent via Savannah
https://savannah.gnu.org/