Unsharp Mask in Paint Shop Pro

One of the most frequent questions I receive concerns frustration about images losing their sharpness when they are resized. Learning to effectively use the unsharp mask makes it possible for your resized images to maintain a high quality appearance. This is especially important when you are creating thumbnail images of your products for quick download time on the page, but still need enough quality to entice your visitors to click.

You may have already noticed that using the sharpen feature often sharpens the image too much to keep that natural look. Using the unsharp mask is often the solution.

Sometimes the help files located within an image editor are not particularly helpful. If you are not familiar with the terms, the following instructions listed in Paint Shop Pro X are likely to leave you pretty lost, and they don’t give a clue on what the appropriate settings might be.

To apply low- and high-frequency sharpening

1. Choose Adjust > Sharpness > Unsharp > Mask.

The Unsharp Mask dialog box appears.

2. Type or set a value from 0.01 to 100.00 in the Radius control to specify the distance (radius) within which the command looks for dissimilar pixels to sharpen.

Photos with close-up subjects and softer details usually require higher Radius settings; photos with lots of fine detail usually require lower Radius settings.

3. Type or set a value from 1 to 100 in the Strength control to specify the overall strength of the command.

4. Type or set a values from 1 to 100 in the Clipping control to specify lightness values that adjacent pixels must have before they are sharpened.

5. Click OK.

As mentioned in my article on Resizing With Paint Shop Pro, I have found it most effective to use the unsharp mask as needed while I am resizing the image. Although Photoshop teaches users to resize in one step, down to the actual size desired, I have not found this to be the same for Paint Shop Pro users. In Paint Shop Pro, the image seems to retain higher quality when you resize in steps, reducing the size by no more than about 25% of the image at a time. I use the unsharp mask following each of these resize steps, as needed.

To locate the unsharp feature in Paint Shop Pro X, from the menu select: Adjust > Sharpness > Unsharp Mask

See Screen Shot

Selecting the correct settings for the specific image you are working on is likely to be a matter of trial and error. Fortunately Paint Shop Pro X provides a preview screen to help you test which settings will be best. I usually start with radius at 1.0, the strength at 20, and the clippings at 3. Again, these settings will vary depending on the specific image you are working with. Adjust the settings up or down until you find what works best.

See Screen Shot

Although several of the following articles I found throughout the internet apply specifically to Photoshop, the concept is still the same. I have found them very helpful regardless of the actual image editor you are using.

Unsharp Mask

The Mystery of Unsharp Mask

Sharpening with Unsharp Mask

Understanding Unsharp Mask

That’s it for the basics of the unsharp mask. In the next tutorial we will be covering how to decide which file format (jpg, gif, or png) you should choose for your images and graphics.


J. Cricket Walker

Small Business Marketing Consultant and Scenic Photographer
Copyright © 2006 J. Cricket Walker of Online Photography Magazine All Rights Reserved

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