Mask operation on a stack

[Pedro J CamelloDr Pedro J Camello]

Hi all,

I have stacks containing time series  of fluorescent images of cells. I want to set all the area outside the cells (easy to mark manually or thresholding) to a specific value. I can do easily a transform of that area to NaN values with the function included in the Process > Math menu, but I would prefer to set the pixels at a value of my choice.

Is it possible to create a mask and then apply that value to the matching pixels in the stack?

Thanks in advance