Noise bias compensation of tone mapped noisy image

This paper proposes a de-noising method especially for a biased noise. Even though a noise is assumed to have zero mean, an image processing such as tone mapping alters this property. Firstly, a precise estimation of the noise bias caused by a tone mapping function is derived considering discontinuity of a general form of the tone mapping. Secondly, a method of compensating the noise bias is introduced investigating estimation from observed noisy pixel values. Thirdly, the derived estimation is applied not only to compensate the noise bias, but also to reduce variance of the biased noise. Finally, significance of the proposed method is evaluated using HDR images in combination with a non-local mean filter.