How do I get Google Photos to store full resolution photos after I changed the setting?

Question

I started using Google Photos to backup all my photos in just standard resolution (their free version). Now I just changed my setting in the auto-backup utility on my Mac to store them in the full resolution. I also changed another setting under Google+ settings to store full resolution images as well. I also increased my Google Drive storage expecting this to rise dramatically. But my storage usage didn't change much at all after I changed to full res images, and when I compare the dimensions from my iPhoto library to the same photo in Google Photos it doesn't match. Google photos version has smaller dimensions.

Do I need to re-upload my whole library to Google Photos? If so, how would I do that? If not, then why isn't it updating my photos to their full resolution?

Answer 1

I think Google will not re-upload your photo again. Because those photos already on Google Plus Photo. However Google will upload full resolution photos the moment you changed your settings. There is a little strange while Google+ count your storage limit.

Google+ Photos: Only photos over 2048x2048 pixels and videos longer than 15 minutes count toward your storage limit. ---reference

So, the answer to your first question is Yes. You need to re-upload all your photos to Google+ Photos. You can use Picasa to re-upload your photos.