Fast Noise Estimation in Images

Estimate the standard deviation of the noise in a gray-scale image.

Description

This is an extremely simple m-file which implements the method described in :
J. Immerkær, “Fast Noise Variance Estimation”, Computer Vision and Image Understanding, Vol. 64, No. 2, pp. 300-302, Sep. 1996
 
The function inputs a grayscale image I and returns Sigma, the noise estimate. Here is a sample use:

I = rgb2gray(imread('sample.jpg'));
Sigma=estimate_noise(I);
         
The advantage of this method is that it includes a Laplacian operation which is almost insensitive to image structure but only depends on the noise in the image.

Acknowledgements

Noise Level Estimation From A Single Image inspired this file.

• Required Products: Image Processing Toolbox
• MATLAB release: MATLAB 7.9 (R2009b)

[Youssef KHMOU]