This paper presents a technique for blindly removing image non-linearities in the absence of any calibration information or explicit knowledge of the imagingdevice. The basic approach exploits the fact that a non-linearityintroduces specific higher-order correlations in the frequency domain (beyond second-order). These correlations can be detected using tools from polyspectral analysis. The non-linearities can then be estimated and removed by simply minimizing these correlations.
Hany Farid, Alin C. Popescu