You should care your uploaded image name so that search engine could easily understand what the image is really about. You can easily turn image name SEO friendly in WordPress by using Clean Image Filenames plugin. This simple WordPress plugin clean or convert accent characters and special characters, like French or German in the file name of files uploaded to the WordPress media library. This plugin is multisite compatible, works with custom upload_dir setups, never conflict with your database or uploads settings.
First of all get the plugin from above link and install it to your blog. See the following example of before and after effects of the plugin on media uploads file naming system:
Before activating the plugin you can see that file name doesn’t change. Now activate the plugin and try to upload same file again:
By default this plugin supports GIF, JPEG, PNG format file. But you can easily add any file type you want by adding your own set of mime types in your theme function. To do that please check plugin description page.
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