Sharpening with Unsharp(!) Mask

In case you didn’t know, Unsharp Mask Filter is used to sharpen images (not blur them). The Unsharp Mask sharpens an image by increasing contrast along the edges in an image. It does not detect the edges, instead it detects pixels that differ in value by the threshold you specify.

It has been around for many years and it became a standard when sharpening images. Once it finds the pixels that differ in value, it increases the contrast between them by the amount you specify.

Here’s an example of a filter being applied:

Unsharp Mask in PhotoshopOriginal on the left, and the sharpened version on the right.

The filter can be found under: Filter->Sharpen->Unsharp Mask.

Unsharp Mask Filter

Here are the options you can find in Unsharp Mask Filter:

Unsharp Mask Filter

  • Sharpen Amount – it controls how much darker and lighter the edge borders become (or how much contrast is added at the edges).
  • Radius – it affects the size of the edges to be sharpened. Smaller radius enhances smaller scale detail. When using higher values, halos at the edges can appear.
  • Threshold – this slider controls how far apart adjacent tonal values have to be before the filter does anything. Low values have a greater effect as fewer areas are excluded.

And that’s it for today. I hope you enjoyed it and see you tomorrow. 🙂

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