Almost every one of us, who have digital photo camera, saw "grainy" photos at least once. That's thanking to colored pixels (so-called grains, speckles) that are present on photos, but do not exist in the reality.

There are several causes why the noise happens to digital photos: long exposure times, heating of the camera sensor, high ISO settings, matrix defects, small pixel size etc. The effect is very frequent to the consumer digital cameras that are built on CCD or CMOS sensors.

Digital noise is very unpleasant artefact that spoils really good shots sometimes. Every shot corresponds to a unique moment which will never happen again, and the only thing we have to do with a cool, but noisy photo is to retouch it slightly to make it perfect.

Does such a post-processiong software exist? Yes it does. There are several noise reduction photoshop pugins (for both windows and macOS) specially designed to remove noise grains from digital photographs:

http://www.digital-photography-software.com/archives/27

The utilities allow reduction of (together and separately): luminance noise and color (chroma) noise. Additional options include fading, blurring and sharpening edges.

So, removing of the most unpleasant picture imperfection - the digital noise - is possible and much more easier than one can imagine. Due to modern image processing algorithms, the plugins can work almost automatically, so noise reduction does not require any advanced computer skills from a photographer.

Noise reduction is made easy nowadays.