This article discusses a feature introduced in Photoshop CS2, the easy color noise reduction tool. Earlier, we described two efficient methods for color noise removal. Those tips were also available to those using even earlier Photoshop versions. Now we do a favor to lazy owners of CS2 or newer versions, introducing a much easier possibility.
Load the photo in Photoshop
No doubt the red-and-green confetti rain looks quite weird in the blue sky. This is a classic example of color noise, which, as all noise types, is very annoying in homogeneous areas. This is just a part of the original photo, but this red snow distracts our attention rather strongly from more important areas.
To get rid of it, you only need to find Filter/Noise/Reduce Noise in the menu. This is how its dialog looks like.
Getting the color noise
Although the image contains luminance noise (grains) as well, let’s stick to color noise until another time.
If you only want to remove color noise, use the third slider. But before, decrease Strength and Sharpen Details to minimum. The former deals with luminance noise, and the latter re-sharpens details lost in doing so. For us, only the Reduce Color Noise slider is important now. In this example, we set it to 90%. The higher the value, the stronger the filtering. Take care though, an overly high value can strongly wash the colors. The image will be similar to when you try to paint with aquarel onto wet paper. When adjusting this slider, try to find the balance between the intensity of noise reduction and the necessary washing of colors.
Without color blots
The zoomed image on the left shows the original, while the right one is the filtered picture. Since the other sliders were reduced to 0, details have not changed the least bit, but the sky got a more consistent color.