Online blind calibration of non-uniform photodetectors: application to endomicroscopy

We present an original method for the online blind calibration of non-uniform photodetectors. The disparity of the detectors may arise from both irregular spatial arrangement and distinct slowly time-varying photometric transfer functions. As natural images are mostly continuous, the signal collected by neighboring detectors is strongly correlated over time. The core idea of our method is to translate the calibration problem into relative pairwise calibrations between neighboring detectors followed by the regularized inversion of a system akin to gradient-based surface recovery. From our blind calibration procedure, we design an online blind calibration pipeline compatible with clinical practice. Online blind calibration is proved to be statistically better than standard offline calibration for reconstructing endomicroscopy sequences.