There is a photo of the document on A4, is there an app or software that makes them look like a scan?

Question

linux

Those. sprinkle and convert the right-hand paper to a rectangular one.
App - for android, software - for Linux, preferably free.

Answer 1

Under the android there was a camscanner, under the line you can use the gimp.

Answer 2

For android there is ClearScanner.
Under linux, I don’t know highly specialized software for this, but you can definitely do it in gimp.