I have a black-and-white diagram (floor plans) scanned from a printout. It's mostly OK, but some of the lines are visibly faded or blurred in places, so it "looks" scanned.
I've tried various options in Paint.NET so far without any success. I could download any free software that would do the job. I could probably get access to Photoshop as well (not sure which version), but I wouldn't even know where to start with that.
Is there an easy way to make them into clear, sharp lines?