Grain Surgery, Visual Infinity's new plug-in for Adobe Photoshop 5.5 and later, is a powerful and easy-to-use noise-manipulation program that lets you remove noise from an image, add noise to an image, and copy one image's noise to another.
What's All This Noise about Noise?
Experienced designers typically employ blur or despeckle filters to reduce noise from digital cameras or grain from scanned images. Although these tools can be effective, they also have a tendency to eliminate important image detail.
Grain Surgery takes a more intelligent approach to noise removal. To understand present noise, the program checks areas of your image that contain simple, flat colors. It then removes recognized noise patterns from the image.
The plug-in's simple dialog box includes a large preview window with an easy-to-use slider control for specifying how much noise reduction to apply. You can also set the number of noise samples to use and where they should be taken from.
Grain Surgery's results are impressive but not perfect. Though it does a very good job of removing noise, it also tends to soften fine image detail.
Got a Match?
You can use Grain Surgery's Add Grain tool to add noise and grain to an image. In addition to controlling grain size, intensity, and saturation, you can select grain options that mimic specific kinds of film.
The plug-in's Match Grain feature can analyze the grain in one image and then add it to another image to help you create more-believable composites.
Macworld's Buying Advice
Grain Surgery will be a good addition to almost any editing arsenal. There are other techniques that may remove noise as well as Grain Surgery does, but the program's adding and matching features make it worth its price.