Fast noise variance estimation

The paper presents a fast and simple method for estimating the variance of additive zero mean Gaussian noise in an image. The method can also be used to give a local estimate of the noise variance in the situation in which the noise variance varies across the image. It requires only the use of a 3 x 3 mask followed by a summation over the image or a local neighborhood. A total of 14 integer operations per pixel is necessary, The method performs well for a large range of noise variance values, In highly textured images or regions, though, the noise estimator perceives thin lines as noise. (C) 1996 Academic Press, Inc.