Sharpening in Luminosity Blend Mode

Clive R. Haynes FRPS

An improved method of Unsharp Mask using Luminosity Blend Mode

To avoid sharpening the colour information which can reveal an increase in visible 'colour noise', sharpening is often better carried out in the monochrome portion of the image known as 'Luminosity'.

The Luminosity (Lightness) content of the image provides the essential the structural detail of the picture.

To sharpen the Luminosity content only, copy the image to a new Layer.
Change the Blend Mode of this Copy Layer from 'Normal' to 'Luminosity'. To do this, click on the drop-down arrow next to 'Normal' at the top left of the Layers Palette and from the drop-down menu list of Blend Modes choose 'Luminosity' at the bottom - see screen grab.

Use Unsharp Mask or your preferred sharpening method in the usual way.

For examples of 'Colour Noise' and how Luminosity Blend Mode overcomes the problem, click on the link below.

Sharpen with Luminosity continued

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