Image Blur: Privacy Masking, Background Effects, and Selective Blur
Blur softens detail in an image β useful for hiding sensitive information (faces, license plates, credit cards), simulating depth-of-field effects, or creating subtle background textures. This guide covers what blur can and can't do.
There are several blur algorithms in common use. Gaussian blur (the default) creates a soft, natural-looking smoothing. Box blur is faster but produces a more 'mechanical' look. Motion blur simulates movement. Radial blur creates a circular streak. Each has different visual properties.
Privacy use: what blur actually hides
- β’Heavy Gaussian blur (radius 20+ on a face) generally cannot be reversed. Safe for hiding identities.
- β’Light blur (radius < 5) can sometimes be partially undone with deconvolution. Don't trust it for true privacy.
- β’Pixelation (mosaic) is also unreliable β pixelated text in particular can be reconstructed by AI tools.
- β’For real privacy, replace the area with a solid color rather than blurring or pixelating.
Extended FAQ
Can blurred faces be unblurred?
Light blur sometimes; heavy blur (radius 20+) effectively cannot. AI deblurring works on cinematic motion blur but generally fails on aggressive Gaussian blur designed for privacy.
Is blurring enough to redact a credit card or social security number?
No. Use a solid black box. Blur can be partially reversed by AI on text β replace, don't blur.
Are my images uploaded?
No. The blur is applied to a canvas in the page. This matters here: faces and documents are the usual reason to blur, and neither is uploaded.