D28767: SEP Focus improvements

lancaster added a comment.


  "Rob, I actually disagree that you get the accurate saturation value. E.g. your technique wouldn't work for signed shorts or signed bytes or floating point where the range is 0 to 1.0, or for that matter, cameras where Indi would put out 0-4K values, etc. In the end, I think we'll need a user-supplied input for this, but all that, I think, should get worked out when you complete your Sextractor parameter integration, and this could be one of the parameters that we offer the user the ability to modify. Until then, I believe this will be good enough. It shouldn't do any harm, and it might improve the situation over the current system. I did, though, modify my code to check to see if it was a byte type, and if so, change the saturation threshold to 250."
  
  Hy you are of course correct on this, and I have not fully finished it yet as you pointed out. One possible thought I have on how to fix this is to either divide by 2 or raise to one less power of two for signed data types, but the only way I can think to determine whether it is signed or not is to just have an if statement or case switch statement based on the types that should be signed.  I am not sure that we can determine what saturated means for a float or double image, but we might not have to because their max value is incredibly high.  I did already make a user supplied value, basically a threshold percentage of saturation they would like to remove, I think this will be easier for end users to work with, assuming that I can get the data types worked out.

REPOSITORY
  R321 KStars

BRANCH
  sep-focus-improvements (branched from master)

REVISION DETAIL
  https://phabricator.kde.org/D28767

To: murveit, mutlaqja, lancaster, TallFurryMan
Cc: kde-edu, narvaez, apol