1. Create a text box & delete all the text.
2. Place 1 full stop in the text box & colour the full stop to the background of the image or page.
3. Hit the return key a few times to open the text box to the size you want & pull the blue tags to widen the box to the size of your image.
4. Place over the top of the image.
5. Now Publish.
NOTE: Do not do this if you have a link in the image. It will stop the link working.
This certainly isnít any way full proof, but will make it just a little harder for some.