how to add a watermark to load image?

In CKFinder there is a plugin called watermark. You can configure and use it.

Please add this:
include_once "plugins/waterkmark/plugin.php"; to CKFinder's config.php file in place where other plugins are added.
Above this line add something like :

    $config['Plugin_Watermark'] = array(
        "source" => "logo.gif",
        "marginRight" => 5,
        "marginBottom" => 5,
        "quality" => 90,
        "transparency" => 80,
    );

logo.gif in this case is stored in CKFinderPath/plugins/watermark directory.
This should works fine. Please remember that this adds watermark to images uploaded by CKFinder (during upload).
If you have more problems with this, please reopen this ticket.

As I wrote in http://drupal.org/node/1782288#comment-6477510 watermark plugin is from CKFinder, so it add watermark to images uploaded with CKFinder. When you turn it on and upload new image it will get watermark. The same should happen if you change image size in CKFinder.

i am webmaster i create new cms and include it ckfinder but i coudn't active watermark plugin in ckfinder

Please help me i ask you

include_once "plugins/waterkmark/plugin.php"; should be include_once "plugins/watermark/plugin.php";

if anyone is having any issues :-), great tool through.