'Sharpening with a 'High-Pass Filter'

Clive R. Haynes FRPS

This is an alternative method of sharpening an image and one that presents an amount of 'flexibility'.
It also has the advantage that it's quick and easy to do.

Above: This image of the ruined Abbey of Maillezais will be our example


The Method

Open the picture as a Background Layer

Make a copy of this layer, placing it on the layer above

Go to: Filter > Other > High Pass

Set High Pass radius to between 4 and 8 - this increases the 'fringe' effect


(Above: the High Pass filter dialogue box and effect on section of image)

Desaturate (via Image > Adjust > Desaturate) the High Pass effect - this is to prevent 'colour fringing'

(Above: the desaturated image )

Set Layer Blend mode to either 'Soft light' or 'Hard Light' - choose whichever suits the image
The opacity setting, for the layer, will influence the sharpening effect






(Above: Layers Palette with 'Blend Modes' window & menu)
(Above: Application of a 'layer Mask')

A further refinement is the application of a 'Layer Mask'. This enable parts of the 'sharpening layer' to be selectively 'erased' (using black f/g colour) or 'restored' (using white f/g colour) and a suitable brush.

For more information about the uses and applications of Layer Masks, go to 'Delving Deeper into Layers'


Above: Detail from final image.


Related Topics
Selective Sharpening
Sharpening Edges Gently
Sharpening in 'Luminosity'
Sharpening Texture with 'Emboss'
Know-How Contents
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