> For the complete documentation index, see [llms.txt](https://astra-image.gitbook.io/astra-image-6.0/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://astra-image.gitbook.io/astra-image-6.0/processing-tools/unsharp-mask.md).

# Unsharp Mask

This is a classic unsharp mask tool for sharpening images. It uses a blurred copy of the original image and a simple algorithm to achieve a sharpening effect.

<div align="left"><figure><img src="/files/QWklDVMqIWTIoVh4Dr8r" alt="The Unsharp Mask tool."><figcaption><p>The Unsharp Mask tool.</p></figcaption></figure></div>

**Strength**\
This sets the strength if the sharpening effect.

**Radius**\
This sets the size of the filter using in computing the unsharp mask. Smaller sizes enhance smaller details and lager sizes enhance larger details. However, when set to high values, halos may appear around strong edges.