Google Photos has an additional option to upgrade old photos with Ultra HDR, improving the quality of old images using the available tools on the application. Old photos after converting to Ultra HDR will have more colors, much more vivid. Below are instructions for upgrading old photos with Ultra HDR on Google Photos.
How to upgrade old photos with Ultra HDR Google Photos
Note, this feature is said to be coming in version 7.24.0.747539053 for some users.
Open the image on Google Photos, then tap Edit at the bottom of the screen, then scroll to the adjustments tab and tap Ultra HDR.
In the screenshot above, you can clearly see the difference between the standard photo and the new Ultra HDR-enhanced photo in Google Photos. The converted photo is labeled 'Ultra HDR' in the details, and its file size is significantly smaller. That's because Ultra HDR photos use a smaller gain map than the original photo. This gain map stores information about brightness, allowing your device to display brighter, more colorful photos without having to store as much data as a full-resolution photo.