Hello,

You can try use this addon Image Block

Other settings to images:

1. Go to about:config page.
2. Search for permissions.default.image change its value to:
   • 1 – Allow all images to load, regardless of origin. (Default)
   • 2 - Block all images from loading.
   • 3 - Prevent third-party images from loading.

• about:config
• http://kb.mozillazine.org/Permissions.default.image

You can use the SQLite Manager extension to generate a list.

• SQLite Manager: https://addons.mozilla.org/firefox/addon/sqlite-manager/

1. Open Profile Directory -> permissions.sqlite -> Go
2. Hit the "Execute SQL" tab
3. Use a SELECT like this:

SELECT id,host,type,permission,expireType,datetime(expireTime/1000,'unixepoch','localtime') AS expireTime,appId,IsInBrowserElement
FROM moz_hosts
WHERE moz_hosts.id AND type LIKE "image"
ORDER BY moz_hosts.id ASC

You can display more permission types at once:

SELECT id,host,type,permission,expireType,datetime(expireTime/1000,'unixepoch','localtime') AS expireTime,appId,IsInBrowserElement
FROM moz_hosts
WHERE moz_hosts.id AND (type LIKE "cookie" OR type LIKE "image")
ORDER BY moz_hosts.id ASC