Neat Image: An Excellent Noise Reducer

Neat Image is a plug-in for Photoshop 7 through CS4, as well as Photoshop Elements and Apple Aperture, that reduces image noise and grain in digital photos and scans. (They also have a standalone version, and a version for video!)

It works well at reducing noise in low-light action photos, as well as in portraits, in files of any format, including Raw.

For automated noise removal, you can download noise profiles for many digital cameras, or you can easily create your own. If you set it up as an Action in Photoshop, you can apply it to batches of images automatically. It can automatically match a profile to an image based on its EXIF data, and intelligently sharpen details as it removes noise.

In addition, it can remove film grain from scanned slides and negatives, JPEG artifacts from over-compressed images, and color banding.

Neat Image costs $34.90 or $69.90, depending on whether you want the automation features and support for 16-bit images. I recommend it highly.