my plan was to use the treshold function (black and white, dark background) and to select with the colour picker my region of intrest.
This worked absoloutly fine until I reinstalled ImageJ/Fiji. When I press now Ctrl + Z or even go in the menu Edit -> Undo (with the mouse) my image turns red/black.
I tried to reinstall the program. I also have this problem on diffrent computers.
Does anyone know why this happens?