How to Remove Moire Patterns From Photos

Get rid of the moire pattern that can result from scanning images.

Scanning photos from books, magazines, and newspapers often results in an unsightly interference effect called a moire pattern. Some photo scanners have a de-screening function, but you can also use Photoshop to manually remove the unwanted effect.

Moiré reduction on a photograph of a painting.

What Is a Moire Pattern?

A moire effect happens when patterns collide, specifically when a striped pattern with transparent gaps is laid over another similar pattern. In printing it can interfere with the pattern of dots over a woven fabric. In television and digital photography, the "rippling" effect of a moire pattern can be seen when someone wears a shirt or jacket with a particular kind of weave or striped pattern. The effect is caused by the overlap of the pattern with the interlaced image scanning of a digital television. It explains why you never see a TV host or news anchor wearing any sort of patterned material.

For photographers, moire patterns often occur when scanning a printed photograph from a magazine or newspaper. Though you can't see it, digital photographs are composed of many tiny dots that scanners can see. Fortunately, you can use Adobe Photoshop to reduce most or all of a moire effect. 

How to Remove a Moire

Follow these steps to remove a moire pattern in Photoshop.

  1. If you can, scan the image at a resolution approximately 150-200% higher than what you need for the final output.

    Be aware that this will likely result in a very large file size, especially if the final image is meant to be printed.

  2. Duplicate the layer and select the area of the image with the moire pattern.

  3. From the Photoshop menu, select Filter > Noise > Median.

  4. Use a radius between 1 and 3. Typically the higher the quality of the source, the lower the radius can be. You may find that 3 works well for newspapers, 2 for magazines, and 1 for books.

  5. Zoom to 100% magnification and apply a small, 2-3 pixel Gaussian blur using Filter > Blur > Gaussian Blur.

  6. From the Photoshop menu, select Filter > Sharpen > Unsharp Mask.

  7. Exact settings depend on the image resolution, but you can use these specifications as a starting point:

    • Amount: 50-100%
    • Radius: 1-3 pixels
    • Threshold: 1-5

    Adjust the settings until you like what you see.

  8. With the new layer selected, tone down the effect by reducing its opacity to 0 and then increasing the opacity until the moire disappears in the underlying image.

  9. Select Image > Image Size and reduce the resolution of the image.

If you still see a pattern after applying the Median filter, try a slight gaussian blur before resampling. Apply just enough blur to reduce the pattern.

If you notice halos or glows in the image after using Unsharp Mask, go to Edit > Fade. Set the Opacity to 50% and the Mode to Luminosity. (This is not available in Photoshop Elements.)

Another Quick Approach

There will be occasions where a moire pattern will appear in a photo. This is very common in clothing with striped patterns. Here's how to fix it:

  1. Open the image and add a new layer.

  2. Select the Eyedropper tool, then select the color of the fabric, not the moire.

  3. Switch to the Paintbrush tool and paint over the item with the moire.

  4. With the new layer selected set the Blend Mode to Color.