Radiometric Calibration from Noise Distributions

A method is proposed for estimating radiometric response functions from noise observations. From the statistical properties of noise sources, the noise distribution for each scene radiance value is shown to be symmetric for a radiometrically calibrated camera. However, due to the non-linearity of camera response functions, the observed noise distributions become skewed in an uncalibrated camera. In this paper, we capitalize on these asymmetric profiles of measured noise distributions to estimate radiometric response functions. Unlike prior approaches, the proposed method is not sensitive to noise level, and is therefore particularly useful when the noise level is high. Also, the proposed method does not require registered input images taken with different exposures; only statistical noise distributions at multiple intensity levels are used. Real-world experiments demonstrate the effectiveness of the proposed approach in comparison to standard calibration techniques.