Recently I have been trying to scan some sports cards. Unfortunately, when I try with both my relatively new HP Deskjet printer/scanner 3520 or my older Dell printer/scanner I get the same result, little wavey lines on the scanned images. The HP is wireless and the Dell is wired through usb, and both get the same result. I've tried raising or lowering the DPI on the scans, but that didn't work.
These are a couple images to show what I'm talking about, notice see how it happens way more to flesh tones than anything else? What is causing this and how can I get rid of it? Thanks.