Thesis defense of Alice Fontbonne

Thesis defense of Alice Fontbonne, PhD student in the Imaging and Information group, on December 1, 2021 at 2 pm, in the auditorium of the Institut d'Optique in Palaiseau, on the topic: "Joint design of optical systems and image processing - A new approach to high-level optical design".

Abstract: "Today, most imaging systems consist of a complex optical system, a detector and digital processing. Conventionally, these blocks are optimised separately from each other, with different criteria. This thesis investigates the possibility of jointly optimising the optical and digital processing parameters, a method referred to as co-design. A first approach to co-design is the use of co-optimised phase masks to increase the pro-field of an imaging system. This thesis shows experimentally that masks optimised with the generic model used have exactly the desired performance. It is also shown that these masks are robust to a low amount of optical aberration, and to their use with a wide spectrum thanks to spectral averaging. The second objective of this thesis is to develop and compare methods for co-designing more complex optical systems using professional optical system design software. By comparing a conventional optimisation method, a method that implicitly takes into account the digital processing applied to the image and a method that explicitly takes into account the processing in the optimisation criterion, it is shown that the most efficient co-optimisation method is the one that explicitly takes into account the digital processing. The results obtained can be improved a posteriori by using zonal deconvolution, a restoration method that takes into account the spatial variation of the PSF in the field, and thus partially compensates for the inhomogeneities of performance in the field due to the imaging system alone. It is shown that using a small number of deconvolution zones is sufficient to restore images of co-designed systems whereas a more elaborate algorithm must be used for a conventional system. "