Adobe® Photoshop® CS2 Studio Techniques

Advanced Mode

If your image has very fine detail or considerable noise, you'll need to take additional steps to ensure that you don't trash too much detail in the image when you're attempting to remove noise. Color images are made out of three (RGB) or four (CMYK) color components, which are known as color channels. It's rather common to find more noise in one of those channels than the others (Figures 12.20 to 12.22). When that's the case, try applying the noise removal filters to the individual channels before attempting to reduce noise from the image as a whole; otherwise, you might end up trashing the detail in most of the channels just to rid one pesky channel of noise (usually the blue or yellow channel) (Figures 12.23 to 12.25). So the ...