Making photos unique in Google's eyes?

Is there any chance to make photos look unique in Google's eyes without destroing them in any way? Sometimes we republish stuff from other websites (we rewrite it completely) but the photos don't get indexed in Google Images. We cut them in different size, but it doesn't help that much. Any tricks to get better rankings both in Google and Google Images ?

Thanks!

There is a thing called image hashing and that's how google/facebook/twitter/instagram or any reverse image search engines finds similar/duplicate images. You can simply change the hashes to make them unique again.

Download and play around with this free software :

The images that rank on Google are not usually the original ones. Some rank higher than the others because of their page's traffic. You should check if your content is optimized for search engines. Starting off with a powerful content would lead to the popularity of your page. Image ranking would then follow suit.