Noise will convey some superfluous information. It may be reproduced in the images like some extra lines, black and white dots, images with checker board effect, smeared edges in the image, non-uniform illumination and blurred edges if suppose either the camera or object is moving. In order to do image analysis with noisy image care must be taken to understand the noise effect by modeling it with the prior knowledge gained about it. These unwanted artifacts are caused by the Charge Coupled Device and Complementary Metal Oxide Semiconductor sensors present in the camera. The noise models are analyzed with the points spreading function (PSF) and modulation transfer function (MTF), Probability density function (PDF) and Histogram. The figure 1 depicts some of the basic and standard noise models available.
Various noise models