Hi codewalker, maybe this can help you or you can get an idea.

I've had a similar issue in a mail-to-fax context: the fax could be too black, maybe for an error. So, I cycle through the ps file (I create a ps from tiff by requirement) and count the frequency of '0' characters ('black' in ps). If this is too high, I deduce the image is too black.

Can you dig into the image and count the values, if there are only 'black' and 'white' or various 'gray' or if there are other colours?

What do you think about?