Determining and changing the intensity of given pixels




I was measuring the protein signal of a cell and unfortunatelly the medium also gave a signal, even stronger, than that of the cell.
In the black/white pictures the background (medium) is brighter than the cells.
My question is if has everybody met or solved this problem.
Basically the background doesn’t cover the whole picture, it is only between the cells.
Noise reduction doesn’t help, and I couldn’t get better pictures neither with changing the minimum in the Brightness/Contrast.
What I can think of as a solution is to changing the intensity of the medium to zero.
Is there any method for this accoording to your knowledge (to determine the intensity value of those pixels where there is only medium and than change this intensity to zero in the whole picture)?
It might modify the signal also, but I’d just like to give it a try.

Thank you,



It would be great if you can post an original image file here… this way we can access your same dataset to try to recreate the issue you are having and better find solutions.



Try Edit > Invert and have a look.