The lack of complete spatial incoherence of the optical field in the object plane of an imaging system results in a nonlinear relationship between the object and image intensity distributions. The problem of correcting such nonlinear distortions (which are quadratic and have a nonzero spread) by using post-detection image processing is addressed. A minimum mean-square-error linear filter is determined and its performance assessed by computer-simulated examples. Results of restoring images in a Kohler illumination system are obtained for different source sizes (i.e., different degrees of spatial coherence) and for different pupil sizes. Limits in which linearity is approached are determined.
Bahaa E. A. Saleh,
"Correction Of Nonlinear Blur Due To Partial Optical Coherence", Proc. SPIE 0194, Applications of Optical Coherence, (25 October 1979); doi: 10.1117/12.957916; https://doi.org/10.1117/12.957916