How do I make Iceweasel\Firefox only display images on specified sites?

Question

Summary:

In Iceweasel (it's effectively Firefox), I want to block all images, but allow images on websites I specify. But the standard method to do this is not working.

The way you're supposed to be able to do this is as follows. In Iceweasel, select Edit/Preferences/Content and UNCHECK LoadImagesAutomatically. Select Exceptions, enter a website name, select "Allow". Now, Iceweasel should display images for websites with the "Allow" designaton, but not for any other site.

But images are NOT displayed on the "Allowed" sites. NO images are shown on any sites. And I've got the NoScript extension disabled. I have no other extensions.

Am I doing something wrong? If I have to use a workround, I don't want an extension that just toggles images on and off. I want to have images blocked by default, and only allow them on sites I choose. Many thanks if you have a solution.

Full Details:

I'm using Iceweasel 10.0.4. Is this an Iceweasel bug? Is there a workround?

CHECKING LoadImagesAutomatically does display images on all sites as you'd expect.

Answer 1

You can do that with a user stylesheet by using @-moz-document, e.g.

@-moz-document regexp('^(?!https?://(www\\.foo\\.com|www\\.bar\\.com)/).*') {
  img { display: none }
}

Note: if you do not want such not-displayed images to be downloaded, then instead of the user CSS solution, you can use the Greasemonkey extension and write a script to remove all the img elements (except for some specified sites). This will not work for img nodes that are added dynamically, though. And this may also break some scripts (if they expect to find some img node).