shawfactor

This plugin allows you to create duplicate images in the media library, rather than having to create a new copy of the image and upload it to WordPress again.
It works by copying the post and its metadata into a totally new file in the media manager. Any changes you make to the new copy of the attachment — updating the caption or cropping, for example, will only be applied to the new attachment, not to the original.
This is useful if you want to edit or crop an existing image without effecting the original
To use, go to the Library tab and you will see a copy file link below each media (this will only appear in list view, see faq)

LH Copy Media File

Thanks! It does what it's supposed to do.

Great plugin! Does what it's supposed to.

Allows you to create duplicate images in the media library.

zitrusblau

This plugin can be used as a discrete but efficient tool for websites which have to make sure that copyright information for images is mandatory.
How it works: It simply blurs all uploaded images. The original only gets restored when the copyright info is set. 
The text field for the copyright info is provided as a form field in the attachment details view.
A simple but elegant solution to enforce copyright discipline among authors and editors.
This plugin is compatible with the plugin “Enhanced Media Library” (tested with version 2.4.5).

WP Copyright

Enforces copyright discipline by blurring all uploaded images as long as the associated copyright info is undefined.

LH Copy Media File vs WP Copyright