WooCommerce Watermark plugin allows you to secure your product images with a watermark. You can either add text or image watermark whichever suits your business requirements. Create rules to specify products or select a whole category to automatically apply watermarks.

Demo:

https://tinyurls.ca/axczK

https://www63.zippyshare.com/v/1xu4mdDX/file.html

https://mega.nz/#!quYjTA7D!6EJZwgrFE0sq3FILK1hpDOaBrMrJsk6UwqycYOxkIl8

http://uploadseed.com/2Tb