Pixelate vs. Blur: Which to Use When Redacting Photos

The problem

People argue about whether a mosaic or a blur is “more secure”, and pick one on gut feeling. The honest answer is that both can fail. A light blur on a clear face can leave enough shape and colour that a friend recognises it. A coarse mosaic with a few large squares can be partly reconstructed or simply guessed, especially on small text.

The mistake is treating the look as the safety. They are two separate choices.

What PrivShot gives you

Two settings, in Settings → Default redaction (and again in the editor for manual marks):

• Style: Mosaic or Blur. This is how it looks.
• Strength: Light, Medium or Strong. This is how much detail is destroyed.

The default is Mosaic at Medium.

What they actually do

• Mosaic replaces the region with blocky cells. PrivShot sizes the cells relative to the face, so even a distant face still gets a few real cells instead of one flat colour. At Strong a face has only about three cells across, which is chunky and unrecognisable.
• Blur smooths the region. At higher strength it is heavier, and PrivShot also keeps the blur from fading out on small regions, so the centre stays fully covered.

How to choose

• Style = how it should look. Mosaic reads clearly as “censored”, which suits documents and public posts. Blur is softer and suits candid photos.
• Strength = how safe. For anyone who must not be identifiable, use Strong, whichever style you like.
• For text, don’t worry. PrivShot always uses a heavy blur on detected text (phone, ID, card numbers, addresses), whatever your default. A mosaic over small characters can stay partly readable; a strong blur destroys them.

Check your own work

Zoom into the result and look at it the way a stranger would. Can you tell the person’s hair, glasses or shape? Can you read any digits? If yes, increase the strength.

Good defaults

• Keep Medium for everyday shots and raise it to Strong when it matters.
• Try the same photo in both styles and compare before you decide.

FAQ

Which is more secure, mosaic or blur? Neither style is safe at a weak setting, and either is safe at a strong one. Choose the style for how it looks and the strength for how safe it is.

What are the strength levels? Light, Medium and Strong. Medium is the default. For faces that must not be recognised, use Strong.

What style is used for text? Detected text such as phone and card numbers always gets a strong blur, whatever your default, because mosaic over small glyphs can stay partly legible.

Where do I set my default? In Settings, under Default redaction: Style and Strength. You can also set them for manual marks in the editor.