possible feature request - background subtraction of a 2D background image

[mperrin]

Also mentioned by Knight, but it's TBD if this is sufficiently a concern to implement.

Right now the background subtraction just works to subtract a constant background level, and that is expected to be sufficient for WFS analyses purposes. As a contingency capability, if there is more spatially variable background than we expect, it might be desired to have some capability to subtract a 2D background image. I.e. load an image A, then select some other image B (via a file selection dialog?) and subtract image B from image A.

[pllim]

Okay, I'll just leave this be until I hear more. If we go forward, it would be a new plugin just because the GUI would be very different from existing BackgroundSub (maybe name it BgSub2D or something). Extra details would be nice:

• What if selected image is too big/small?
• Do we need to check if it is the right kind of image (e.g., using specific header keywords)?
• Do you also want to propagate ERR and DQ?
• Do you want to set any special keywords in the subtracted image indicating that background has been subtracted (like what happens in a pipeline)? This is in addition to existing logging mechanism.

If you decide it's a no-go, then feel free to close.

[mperrin]

yes agreed that was not a fully detailed feature request! Just capturing this as a note in real time during the WFSCOWG meeting ongoing right now here in the board room!