在cpg的plugins folder中，有一個叫 CPGMark 的，install 就得，好易用。
INSTALL
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* Unpack the archive and upload the "CPGMark" directory structure to your Coppermine gallery's plugins folder.
* Login as an admin, go to config, then "Manage Plugins"
* Find the CPGMark entry in the available plugins and click install.
* When logged in as admin you will see the CPGMark Config button in the toolbar. This allows you to set when images are watermarked and set the location and image file names used by the system.
* Watermark images should be uploaded to watermark_image_file_path/user_id
and named as per names set by admin.
* If you want to see a preview of your watermark settings on your own image, name a suitable image file preview.jpg and upload it to the same directory as your watermark images. If this file doesn't exist, the plugin uses it's default image.
* When logged in as a user you will see CPGMark in the menu. This allows you to choose whether to insert graphical or text watermarks and set their placing on the image.
