Click here to see in five minutes how I create fully searchable black and white PDFs from photos. Such files are relatively small and can be made to such a quality that you could easily mistake them for a PDF coming straight from the publisher.
The video also gives you a sense of how long this process takes. For this small book it took me half an hour.
Links to software:
Resize Sense (Surely there is an equivalent for Windows)
ScanTailor (Originally for Windows, but with some effort it can run on OSX as well)
Acrobat Pro (expensive; try getting it through your university)
Comments on this workflow are of course welcome!