Scans of CD/DVD medium label sides: technique?

coverartarchive
cover_art_technique
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#1

Been trying to scan the side of CDs that has the label and contents info in text.
Results disappointing so far.
I’ve seen some good images in the CA archives though.
How to get good images?


#2

What specific problems do you run into? I always scan CDs the same way I scan other images: at 600 DPI with minimal automatic post-processing.


#3

If you mean the package spine, you have to detach the plastic tray to pick the back cover up and scan it without the jewel case, with the two spines unfolded flat.


#4

The images of actual CDs have 2 overly dark segments, one each side of the central hole.
Each dark segment takes up about one sixth of the disc surface and transitions through a rainbow of colours on both edges.
The remainder of the image is OK.


#5

Ah, the matrix.
@kepstin explained somewhere that optical scanners had these rainbows and contact scanners did not.
I am not sure of the two technical names but contact scanners are focuses at surface only, all things not in direct contact with the glass will be out of focus (blurry).
Optical scanners have a deeper depth of field but have those rainbow optical effects.


#6

HI @mmirG - If you’re seeing a pattern that looks like this: https://www.kepstin.ca/wp-content/uploads/2016/09/13842659217.jpg
then you have a “CCD” optical sensor scanner with a CCFL (florescent light). Unfortunately, there’s not that much you can do about the pattern…

One suggestion that might work is to scan the CD, then rotate it 90° and scan it again. You can then combine the two images in photoshop or gimp to take the best parts of both.

If you’re planning to do a lot of CD scanning, it might make sense to look at a different scanner. The ones listed under the “Scanners with CIS Sensors” header on https://www.kepstin.ca/blog/recommended-scanners-for-album-art-scanning/ won’t have this issue with colors on CDs.

If you’re feeling like a DIY kind of person, you can also try finding a sheet of diffuser plastic and put it between the scanner bed and the CD. I get good results with that: https://www.kepstin.ca/blog/scanning-cds/