I'd like to consoldate all my photos into one catalog in Elements. The problem is that for several years, I've been uploading my iPhone photos directly to Google photos, while my digital camera photos (and photos received from friends) live on both my hard drive and in Google photos. Furthermore, the Google photos are compressed and I don't want to preserve the compressed copies of my hard drive photos; I want just the iPhone photos that I don't already have.
Does anyone have any suggestions for how to merge my Google photos with my hard drive photos and end up with the highest quality option where there are duplicates? Are there Elements features that could help? I've got about 50k photos so it's a sizable problem. I'm on a MacBook Pro running Catalina if that matters. Thanks!