Adobe Photoshop’s Unsharp Mask filter compares each pixel in an image to neighbouring pixels – the greater the contrast between two pixels, the more it increases the contrast. This results in a halo effect around edges that appears to increase an image’s sharpness.
The Unsharp Mask filter can also have the undesirable effect of exaggerating texture in flat areas, noise introduced by a scanner, and artifacts from JPEG compression. Even when happy with your Unsharp Mask settings, there’s still a rub. If the image is for online use, then the sharpened on-screen version will be what you get when it’s uploaded. However, if it’s destined for print, there’ll be a difference between the on-screen version and how it looks on paper after being put through the halftoning print-process.
nik Sharpener Pro is a clever plug-in that not only automatically sharpens images optimally, but offers output profiles designed to retain that image’s integrity – whether it’s being output on a laser, inkjet or an offset press.
Sharpener Pro’s options appear in the Photoshop filter menu, and all trigger an easy-to-use preview window. The great thing about this plug-in is that – although what it does is complex – it’s fully automated.
The image-quality options on offer are optimized by default, and so will rarely need tweaking. One interesting feature is the eye-distance settings: these compensate for the distance between image and viewer (a magazine as opposed to a poster, for example). There’s also a printer-quality slider, that compensates for varying paper and printer standards.
For graphics pros who use Photoshop’s Unsharp Mask, Sharpener Pro will prove a boon. However, for home use, the boiled-down Sharpener – which lacks some fine-tuning features – will prove adequate.
This review appeared in the Expo 2001