hi, I'm looking desperately for an extension that allows me to enter into the body of article, a background image of a window that scrolls parallax ... for instance as used in this link:

mag.newsweek.com/2014/01/24/bangkok-thailand.html

you have something like this? I wish it was simple to use and is compatible with K2 component. Thank you for your attention.

I don't know if there is a plugin that does this but you can construct something like this in your item' page.

You can use the extra fields to add the image on every item between the intro text and full text, for example.
Then just add the code this page uses in the item.php using the extra field you have setup.
You would have to also add the appropriate css and you would have the result in your item page as well.

You could also ask your template developer to help you with something like this.