TYPES OF NOISE:-Noise is an unwanted or distort signal that may corrupt the quality or the originality of the image. When noise is added, notice how "gaussian-like" the histogram becomes. Digital Image Processing using OpenCV (Python & C++) Highlights: We will give an overview of the most common types of noise that is present in images. Noise has been produced in the image due to transmission. Different noise models including additive and multiplicative types are discussed in the paper.Selection of the denoising algorithm is application dependent. This paper reviews the existing denoising algorithms and performs their comparative study. Temporal vs. Spatial Noise • It is common to assume that: – spatial noise in an image is consistent with the temporal image noise – the spatial noise is independent and identically distributed • Thus, we can think of a neighborhood of the image itself as approximated by an additive noise process Each pixel in noisy image is the sum of true pixel value and a random gaussian distributed noise value [4]. The main challenge in digital image processing is to remove noise from the original image. Below: The image with gaussian noise. Digital image processing techniques can also include restoration. Then, we will show how we can filter these images using a simple median filter. In image processing, noise produces an image that may consist of uneven lines, blurred object, distortion of Gaussian noise Gaussian noise is evenly distributed over the signal. is an important task in image processing. Because it has only 2 colours, there are just two spikes. Our main concern is to remove certain kind of noise. Noise, which may show up as random dots or streaks, can be eliminated through replacement techniques. In general the results of the noise removal have a strong influence on the quality of the image processing techniques. The histogram for each of these images is: The upper image is the histogram for the original image. The nature of the noise removal problem depends on the type of the noise corrupting the image. ECE/OPTI533 Digital Image Processing class notes 239 Dr. Robert A. Schowengerdt 2003 IMAGE NOISE I TYPES OF NOISE • photoelectronic • photon noise • thermal noise • impulse • salt noise • pepper noise • salt and pepper noise The common types of are: II.1: Salt Pepper Noise: Salt and pepper noise is an impulse type of noise. We will show how we can generate these types of noise and add them to clean images. The lower image is the histogram for noisy image. Thus, the main source of image de-noising is Image Digitization. Noise is always presents in digital images during image acquisition, coding, transmission, and processing steps. Some scanned images may pick up tears or lines. 3.1. Several techniques for noise removal are well established in color image processing. It is actually Noise is always presents in digital images during image acquisition, coding, transmission, and processing steps. 3.2. Above: The original image. the types of disturbance, the noise can affect the image to different extent. There are different types of noise is present and each type of noise has different characteristics. So we have to first identify certain type of noise and apply different algorithms to remove the noise.