Yeast count and viability on haemocytometer

Hello all,
I just installed Cellprofiler in order to automatically count yeasts (stained and unstained with methylene blue) on an haemocytometer.
yc2.tiff (423.4 KB)

I tried to adapt the script “example percentage positive” but i do not discriminate the images with phase contrast, only by staining.
I am suspecting that the grid may be a problem too?

Moreover, would intensity differences between alive and stained dead cells be enough to discriminate them?
Thank you for your help!

Have a good day