Yes, it’s possible to take really nice blurred background photos and re-focus the photo after taking it, on the Samsung Galaxy S10. I prefer not to use the Samsung camera app as I find the live focus feature quite buggy and slow to use. Instead, I prefer the Blur Background feature of the classic Google Camera app from 2015, which amazingly works great on the Samsung Galaxy S10.
The only issue is that the shutter sound is super loud, and I haven’t found a way to make it softer yet.
Here’s some example photos taken using Samsung Galaxy S10 using the December 2015 build of the Google Camera app:
Vegetarian dish (food photo) with Blurred Background taken on Samsung Galaxy S10:
Pasta dish (food photo) with Blurred Background taken on Samsung Galaxy S10:
I got my Google Camera December 2015 APK from apkmonk dot com but I can not guarantee the safety of that site. Use at your own risk!