Cache Images is a plugin (download) that gives users option to sideload images that are hosted on other domains to their own site. Sideloaded images are added to WordPress media library so you can use all tools related to images that you can use with images uploaded through WordPress.
Why would you want to sideload images? Although image hosting on remote server has its good sides (like less load on server and less used bandwidth), there are negative sides too. For example, image can be deleted from remote site so you can’t use it, or site owner can prevent hotlinking or even redirect hotlinking requests to images you wouldn’t want to show to your visitors. Last, but not least, there is an ethical moment since remote site owner will pay for resources used by your server.
You can use this plugin by clicking on menu item Cache Remote Images under Tools menu item. On following screen, you will be presented with basic information about usage of plugin and a button Scan which will scan your posts for images hosted on other domains, or button Scan (including linked) which will also scan for images on other domains that are only linked from your site.
After scanning is finished, you will get a list with all domains from which you hotlink images. For every domain, you need to press on a button Cache from this domain that is shown next to domain name. Then plugin will sideload every image from that domain, add image as an attachment of first post where it found it, and update every post where original URL is occurring with new URL.
Since this plugin uses AJAX for sending requests from administration screen, you shouldn’t get out of time PHP errors. Note that it should take some time for sideloading to finish since for every image, plugin needs to sideload image to local server, make all thumbnails, and change original URLs in posts to new location.
Cache Images will handle images hosted on Blogger’s domain in a very smart way so you shouldn’t have to worry about issues with it. Also note that I recommend installation of a plugin WP-Smush.it which will try to reduce file sizes of your images without loss of quality through Yahoo’s free tool smush.it.
If you regularly use images from other domains, you can turn on automatic caching. This caching will be done after you save or publish post. You can turn in on Settings > Media administration page.
This plugin is fully internationalized. You can find .pot file in languages folder where you should place your translation. Please send me your translation by contacting me so that I can include it in next releases. Current translations are:
Cache Images was originally made by infamous Matt Mullenweg, co-founder of WordPress, and I updated it for my own needs, but later decided to send my changes to Matt who in turn gave me rights to update this plugin in wordpress.org SVN repository. AJAX functions are made by fork of code from plugin AJAX Thumbnail Rebuild.
Cache Images is released under the terms of GNU General Public License. It is completely free so if you find it useful you can give something back to authors. Your help could be done by translating plugin to your language, sending bugs and suggestions, promoting plugin in blogs, forums and other websites.
Support for this plugin could be get in comment section of this page or through WordPress support forum (preferred method). Note that I don’t guarantee that I’ll respond to your entries nor that I’ll do it in short period of time. Before posting, please read documentation on this page or on plugin’s page in WordPress plugin directory. I’ll may delete questions for which answers are provided. Please don’t send support question to email, except if you want paid support.