Gradient Removal (Gradiente de color)

[Jack Harvey]

In doing NGC 1313 some of the red frames were shot with the moon up and I have a red gradient in the lower left corner of this image (see below).  I have tried both background tools, masks and curves and hist and find that I black clip the image too much to get rid of this.  Suggestions for gradient removal?

   
De este NGC 1313 algunos de los cuadros de color rojo se disparó con la luna y hasta tengo un gradiente de color rojo en la esquina inferior izquierda de esta imagen (véase más adelante). He tratado tanto de antecedentes herramientas, máscaras y curvas y hist encontrar y que yo clip negro la imagen demasiado para deshacerse de este. Sugerencias para el gradiente de eliminación?

[Juan Conejero]

DBE to rescue

Contrarily to what it may seem due to the strong gradients, this is not a difficult case.

1. Define a set of DBE samples on background regions.


2. Subtract the background model.


3. If necessary, you can apply a second iteration. For this example, this isn't necessary, but I'll show you how to do it anyway for demonstration purposes. Note that I saved the initial DBE instance as a process icon. It's just a matter of double-clicking the icon to reload the DBE tool with the previous set of background samples.


4. Subtract the new background model.


Hope this helps. As I've said, for this example a single iteration suffices (steps 1 and 2 only).

[Jack Harvey]

Boy that works well!!  Thanks!!!!