> is just going to be making up the missing data.

This is generally true. What I find fascinating is the application of information that is not present in the data but that can be confirmed by the data. I’m thinking specifically of deblurring algorithms people use to recover text. If you can guess what font is being used in a screengrab with, say, someone’s bank account blurred out, you can take the i formation contained in the downloaded font and try combinations until you match the blur algorithm that may also be information not contained in the image.

What’s also crazy, is that even if all you do is black out the text, kerning alone can still be used to guess the correct text with some degree of accuracy. I worked on redaction software at one point, and these were very much the types of things we thought about when dealing with text.