The main thing here is not an image processing task but "imaging". you need a lab setup to acquire the right image of these prints first.
How?
Prepare a dark room. Use a constant uniform source of white light, as white as possible. Keep the walls white, as white as possible. Use a good camera, mostly global shutter type. Switch off auto focus. Use the camera on a mount and focus manually. Set it on a pedestal and clamp the prints. Find a way not to disturb anything, don't even touch it between taking photographs of all the papers. THIS IA A HUGE CHALLENGE.
Analysis
Even the best software or professor cannot give you an algorithm that can analyse a better paper from the image. Image analysis is pure subjective. yes, tools can help you quantify some of the things like the contrast, dispersion etc using numbers. But, that is also dependent in the image itself, not the printout. Yes, basic stuff like color range, number of shades of black at the same pixel position (location of the paper). again for this DON'T TOUCH when the INAGING is in process.
So, it's the INAGING that is super difficult here, not the analysis.
As of writing in your paper, mention every care you'd taken for the imaging. You can use other types of photography like infrared etc. Do a survey for the best ways to image a printout for analysis.
Thank you!