You reverse optimize storage by going to Settings > iCloud > Photos and select "Download and Keep Originals" -- although they may not all fit on your phone -- not sure how much storage you have and whether all 20,000 originated from your phone.
Locate the photo you want to return to its original state. Tap Edit at the top right corner of the image you want to revert. Tap Revert. Tap Revert to Original and your image will be restored to the unedited version.
Locate the photo you want to return to its original state. Tap Edit at the top right corner of the image you want to revert. Tap Revert. Tap Revert to Original and your image will be restored to the unedited version.
Edit and revert your cropped photo When you choose to edit the cropped photo, you will see a new option on the bottom right in red – "Revert." Click "Revert" if you wish to delete your crop and restore the original photo.
All you have to do is give the iPhone a shake while the app is still open and the iPhone prompts you to undo the mistake. While the prompt button says "Undo Typing," this button works for accidental deletions, cuts or any other editing you last did in the app.
To access Recently Deleted notes, open your Notes app, and tap "Recently Deleted" from your list of folders. See a note you wish to recover? Tap Edit > select the notes you want to recover > Tap "Move To" > Select a folder to restore the notes to. Phew, your notes are now safe in an active Notes folder!
Click Albums, then select the Recently Deleted album to view its contents. Click Select Photos, then do one of the following: Click Recover All. Select the photos or videos you want to recover, then click Recover.
If the last thing you did in the Finder was to delete a file or files (drag to Trash or select and then File > Empty Trash or Command-Delete), you can select Edit > Undo Move (Command-Z) and the items return to their previous positions.
You can also perform an undo action by swiping your iPhone's screen. To do it, place three fingers on the screen and swipe quickly to the left. You'll see an “Undo” message pop up near the top of your screen, and the last action will be undone.
You can recover deleted photos from your iPhone's Recently Deleted folder or an iCloud backup. You can also recover deleted photos from cloud storage apps like OneDrive or Dropbox. If photos are missing but not deleted, you may find them in the Hidden folder of the Photos app.
Tap on the filters icon and then scroll to the left to select "None." Hit "Apply" in the upper-right-hand corner and, voila! The filter will be removed. You can also change the filter to another one as I did in the image below.
There is no way to recover them. Notes does not have an undo feature and you have no previous backup to restore from.