When it's done as pixels, we use pixelated and pixelation.
You can write:
- They removed the pixelation, thereby showing the face of the person who decided to speak in anonymity.
Wikipedia gives "pixelization", but pixelate appears more common.
Many will write "pixelated" even when it would be more correct to use another word (eg I News referring to a blurred image as "pixelated"):
- blurred out (if the image is made blurry)
- blacked out (made black)
- blanked out (made black or white)
- blocked out
- masked out (any kind of blurring/rectangle/pixelation which prevents you seeing the face)
So you can have
- They removed the blurring, thereby showing the face ...
If it is actually censorship and not privacy, you can also write
- The removed the censoring/censorship, thereby showing the offensive symbol
Very occasionally you see redaction bar Guardian which would be appropriate for both privacy and censorship. You could certainly write
- They removed the redaction, thereby showing the face ...
"Redaction" is quite a formal word.