How to create a mosaic in Photoshop | How to hide part of an image/face

With Photoshop, you can select only part of an image and create a mosaic. If you want to pixelate things like faces, license plates, or people in the background, it's safe to start by duplicating the layer so you can work on it while preserving the original image.

Steps to create a mosaic in Photoshop

1. Open the image and duplicate the background layer.

2. Select the face or part of the image you want to hide using the rectangular selection tool, lasso tool, etc.

3. Open Filters from the top menu and select Mosaic under Pixelate.

4. Adjust the cell size to coarsen the blocks until the original information is unrecognizable.

5. After applying with OK, deselect and check the processing area within the entire image.

6. Save as a different name and export as a JPEG or PNG for sharing.

What cell size should I use?

There is no correct answer regarding cell size. It changes depending on the resolution of the original image, the size of the face, and the size displayed after posting. The important thing is not that the image cannot be read on the editing screen, but that the features of the eyes, letters, and numbers do not remain even if the exported image is enlarged. Small mosaics may look good but provide poor anonymization.

Don't forget information other than faces

In photos for SNS, even if only your face is hidden, information may be inferred from the logo on your uniform, nameplate of your house, car model, map in the background, smartphone notifications, etc. Before making a selection in Photoshop, you can reduce omissions by moving your eyes from the four corners of the image to the center and identifying candidates to hide.

What to check after using How to create a mosaic in Photoshop

The main risk is leaving a small edge of text, a number, or a code visible after editing. When using How to create a mosaic in Photoshop, make the edited area slightly larger than the target and open the exported file once before posting.

When using How to create a mosaic in Photoshop, treat visual softening and redaction as separate jobs. For How to create a mosaic in Photoshop, blur or mosaic can reduce detail, but sensitive text and codes are easier to check with an opaque cover.

Frequently asked questions

How to make the mosaic grain bigger in Photoshop?

Increase the cell size on the mosaic settings screen. Don't decide based on numbers alone; enlarge the exported image and make sure it's large enough that faces and text cannot be discerned.

What is the selection range when you want to make only the face mosaic in Photoshop?

Select the area that includes the hairline and surrounding area, rather than the very edge of the face. If the machining area is narrow, contours and features are likely to remain.