(Yesterday, 04:42 PM)kulharin Wrote: "click and drag to define a selection" sorry, can you clarify a selection of which part of the image? The grey background or the whole thing?
As that short animation. Color Select tool. Bottom of the tool options is a tick-box for Draw mask
With that enabled, click in background area, hold left-mouse-button and drag to right. The selection shows as a magenta mask. Release mouse button to fix the selection.
It is just a way to adjust the threshold value on-the-fly. You mentioned trouble adjusting threshold.
It sounds like you need a good extract foreground from background procedure. Not going to be quick with that type of image.