You might have noticed that under certain conditions, the image acquired with your digital camera has far too much information, thus creating noise and digital artifacts that mar your photo. This is particularly an issue when you're shooting at night and/or with a high ISO in other low-light conditions.
Free Photo Noise Reduction tool is a small and easy to use image editing software which can help you remove a tremendous amount of that noise easily.
To reduce the noise, just move the sliders in the noise reduction panel properly.
The first two sliders affect luminance noise(Grain). The last two sliders affect color noise(colored artifacts).
Amount: Determines how much to reduce the luminance/color noise.
Radius: Adjust the size of the details that luminance/color noise reduction is applied to. Lower values preserve more detail but may also keep some larger size noise.