Noise Reduction in Adobe Photoshop

All images are likely to suffer from noise to a certain extent depending on a number of factors, such as: the ISO level, sensor heat, and exposure time.

Photoshop offers a few techniques for reducing image noise. One of which is the Reduce Noise feature found in the top menu under Filters >> noise >> reduce noise

Reduce Noise Filter is mainly designed to combat the two known luminance and color noise problems, while preserving edge details in an image.

In the basic dialog box, you’re going to want to specify the noise reduction strength being applied to your image. The preserve details slider will specify how much edge information is being preserved in your shot. One thing you want to keep in mind is, the more you want to preserve details, the more edge information will be retained, but the less noise will be reduced. So you have got to balance it out depending on your needs. The reduce color noise slider will allow you to specify the degree of color noise suppression. Also there’s a trade off. The more you reduce color noise, the more your colors will appear to "bleed" and the more your image will be softened. After these adjustments, your image is highly likely to have suffered loss of sharpness to a certain extent, and here you’re going to want to give it back to your image using the sharpen details dial. But I suggest you be careful with that since cranking up this dial too high may introduce artifact to your image.

The basic noise reduction mode applies your settings to the overall image. You might want to specify noise reduction settings as per channel. That’s when you’re going to need to go to the advanced mode by selecting the advanced radio button in the dialog box. You might want to apply more rigid adjustments to the blue channel as it is usually the noisiest of all three channels, and less rigid adjustments to the red and green channels. And of course you’re going to want to specify how much image details be preserved.

When you’re done you hit the OK button on the dialog box and photoshop will apply your adjustments, giving you an image that is noise free to some extent depending on your settings.