Noise Level Estimation from a Single Image

NoiseLevel estimates noise level of input single noisy image. [nlevel th num] = NoiseLevel(img,patchsize,decim,conf,itr) Output parameters nlevel: estimated noise levels. th: threshold to extract weak texture patches at the last iteration. num: number of extracted weak texture patches at the last iteration.

The dimension output parameters is same to channels of the input image. Input parameters img: input single image patchsize (optional): patch size (default: 7) decim (optional): decimation factor. If you put large number, the calculation will be accelerated. (default: 0) conf (optional): confidence interval to determin the threshold for the weak texture. In this algorithm, this value is usually set the value very close to one. (default: 0.99) itr (optional): number of iteration. (default: 3)

Example: img = double(imread('img.png')); nlevel = NoiseLevel(img);

Web page: http://bit.ly/NLest (http://www.ok.ctrl.titech.ac.jp/res/NLE/noise_level.html)

Reference: Xinhao Liu, Masayuki Tanaka and Masatoshi Okutomi Noise Level Estimation Using Weak Textured Patches of a Single Noisy Image IEEE International Conference on Image Processing (ICIP), 2012.

Xinhao Liu, Masayuki Tanaka and Masatoshi Okutomi, Single-image Noise Level Estimation for Blind Denoising, IEEE Transactions on Image Processing, Vol.22, No.12, pp.5226-5237, 2013.