How to scan blu-ray covers nicely?

[Kyo28]

I use Collectorz.com's Movie collector to keep my list of blu-rays up to date and always add a front and back cover scan. Then I can export it to my website to have an online listing of my collection

However, I'm having some trouble to get nice scans of the covers. I prefer to make scans with the blue case included, because I feel that looks nicer than taking the covers out (as blu-ray cases aren't as tall as DVD cases). But I'm having trouble to get nice contrast, even with a good scanner. Any suggestions how to get them nice?

Here's as example of my results (click to enlarge)