Uniform gradation is what you will expect in a good digital photo but sometimes you will find blotchy or pale areas or specks in it. These problems are the digital photo noise. Digital photo noise may also be difference in the colour of an area of the photograph where there should have been smooth colour.
These areas were not present in the original scene you took the photograph of. You will not want digital photo noise in your digital photo which captures a precious moment for which you were waiting for so long and you took so much of pain.
When you shoot in a low light condition or when you shoot in a high ISO setting available in your digital camera, digital photo noise may occur.
In low ISO setting the noise is low. As you go on increasing the ISO for you different needs, the noise also increases. In DSLR (Digital Single Lens Reflex) cameras the noise level is lesser in higher ISO setting also.
Digital photo noise may be of different types like random noise (or salt and peeper noise or independent noise) and dependent noise (or Gaussian noise).
Faulty CCD element can cause random noise where a pixel may be totally different in colour from the neighboring pixels.
In dependent noise you will see noise in many places of the image. Here each pixel value gets changed slightly to a nearby value.
As image sensors are made of row and column arranged pixels so any problems in them show up in the final image as digital photo noise in case of row and column noise.
Reduction of digital noise
To reduce digital photo noise you can follow certain techniques. Shoot at the lowest ISO, shoot a well lit condition, shoot at higher shutter speed, avoid digital zoom if possible. These may not be possible all the time. But you can also resort to photo imaging softwares to remove and reduce digital photo noise. It contains noise reduction filters and despeckle filters.
Noise reduction software
Most of the digital cameras have noise reduction softwares built in it. Also other software solution providers also provide softwares for digital photo noise reduction. These are really effective and can help you a lot with your photographs with digital photo noise.
You can use different softwares to reduce the digital photo noise. You can use noise reduction filter in photoshop, noise filter in Neat Image, SmNR filters for noise reduction, Photoshop CS Noise Reduction Filter andImageConverter Plus. Image Converter Plus is an excellent tool for noise reduction. It removes the different pixels that create digital noise.
In some cases digital photo noise may be wanted to create an artistic look. It depends on the image and view of the photographer.
Author: Bikash Kalita