How to Add Noise to Images in Photoshop CS6
Noise in images consists of any graininess or texture that occurs. Noise filters, such as the Photoshop CS6 Add Noise plug-in, produce random texture and grain in an image.
If you’re new to image editing, you might wonder why you’d want to add noise to an image in the first place. Wouldn’t it be smarter to remove it? Well, sometimes. In practice, you can find a lot of applications that call for a little noise here and there, including:
Adding texture: Objects that become too smooth, either because of blurring or other image editing you may have done, often look better when you add some noise to give them a texture. This technique is particularly useful if one object in an image has been edited, smoothed, or blurred more than the other objects in the image.
Blending foreign objects into a scene: When you drop a new object into the middle of an existing scene, the amount of grain or noise in the new object is often quite different from the objects it’s joining.
For example, say you’ve decided to take a photo of your house and want to insert a certain luxury car in your driveway. Unfortunately, your digital photo of your brother-in-law’s luxo-mobile is a lot sharper than the picture of your house. Adding a little noise can help the two objects blend more realistically. You may even forget that the car isn’t yours.
Improving image quality: Images that contain smooth gradients often don’t print well because some printers can’t reproduce the subtle blend of colors from one hue to another. The result is objectionable banding in your printed image: You can see distinct stripes where the colors progress from one to another.
Adding a little noise can break up the gradient enough that your printer can reproduce the blend of colors, and the noise/grain itself is virtually invisible on the printed sheet.