The noise reduction filter is another tool carried over from Photoshop Elements 3 and enhanced for Photoshop CS2. This tool helps to reduce the grainy appearance of images shot in low light or at high ISO speeds. It can also help to remove compression artifacts from JPEG images. The tool is available from the menu: Filter > Noise > Reduce Noise. As you can see, there are controls for adjusting the strength of noise removal, the percentage of details preserved, the amount of color noise reduction, and the amount details should be sharpened. There is also an option that can help to reduce the appearance of JPEG artifacts from too much compression. In advanced mode, users can also perform noise reduction on a per channel basis. Users can also save specific settings as a preset.
The JPEG artifact option, per channel noise reduction, and ability to save presets are all enhancements over the noise reduction filter in Photoshop Elements 3.