Mosaic or solid masking?

Match the masking method to the sensitivity of the information.

What mosaic leaves behind

Mosaic reduces visible detail but can preserve colours, shapes and the approximate length of text. Making text hard to read is not proof that it cannot be identified.

Use solid masking for sensitive details

Names, identity numbers, phone numbers, addresses and signatures usually call for a solid mask. Cover the full region with a little margin, including the edges of letters.

An illustrative check

Practise on the fictional number 8123 4567. After masking, none of its digits or outlines should be visible. This is a workflow example, not a measured guarantee of anonymisation.

Review after export

Apply the mask, download and reopen the actual output. Zoom in on each covered region. The red selection box is only a selection indicator; it must be applied to become part of the output.

Limits of both methods

Neither option decides what is sensitive or guarantees that every identifying clue and metadata field is removed. Keep an original privately and consider who will receive the edited image.