reverse-selection - i.e. selecting points from the background

[yosun]

how would you recommend reversing this marker detection?

i'm trying to generalize to cases where the background to be removed is mostly known - white with some shadow (for example), with just a single foreground object

[glrs]

Hi @yosun,

I am not sure I understand your question. If you want to keep the foreground object, it should work the same for any background. If you only have white background and just a shadow it should be even easier. You select the points that define the background, e.g. 1 point in the white area and 1 point in the shadow area, and you give them a value of 1. Then select some points that define your object and give them a value != 1.

Let me know if that answers your question. You can also take a look in my stackoverflow answer, as it might be helpful.