Hidden information in screenshots?

zork · 08-16-14, 08:02 AM

Took some screenshots of models in my viewer.

Thought there is sth on my monitor at first:

Nope. It is in the image.

I remember reading about that kind of stuff long time ago. Maybe just fragments from the TGA to JPEG algorithm.

Or is that to find out who leaked WoW alpha images to the press? That would make sense at least. I would watermark my images in alpha state aswell.

*edit*

Tested it. Information is not included in TGA screenshots and JPG screenshots at quality 10. All other screenshots include that kind of fragments. Fragments seem to differ depending on chosen quality.

def9 · 08-16-14, 08:40 AM

I remember reading about this kind of thing a while back. If I remember right its called steganalysis if you want to research it further.

Duugu · 08-16-14, 12:08 PM

You could test some less uniform backgrounds. What are the results?

Nynaeve · 08-16-14, 05:46 PM

Just wondering, have you tested this using a program to screencapture (fraps, etc)? Or are you using the default in-game screenshot hotkey? Would be interesting to know if there are any differences in the screencapture between the two methods.

Duugu · 08-16-14, 05:55 PM

He did them ingame. And it is a watermark.

TOM_RUS postet a link to a deeper description. But the post is deleted now!? Don't know if he did this or if the link was against the wowi rules?

TOM_RUS · 08-16-14, 05:57 PM

Originally Posted by Duugu

He did them ingame. And it is a watermark.

TOM_RUS postet a link to a deeper description. But the post is deleted now!? Don't know if he did this or if the link was against the wowi toc?

Admin removed it.

Vlad · 08-16-14, 05:57 PM

It's a bit odd that the post with the link to ownedcore was deleted.

I mean the content linked was a real thread on this topic. It contains relevant and educational information and Java/C# code to make your own image scanning tool to read this kind of data from your own screenshots.

In any case it's a watermark put on "low" quality jpegs to appear as artifacts, but it contains your wow account name (pre bnet), server name and IP. Basic info to combat private servers I reckon.