Information for efficiency: reconstructing compound objects by quantum imaging with higher-order correlation functions

Quantum imaging generally leads to nonlinear estimation problems intractable for a larger number of problem parameters. We connect the features of the Fisher information with the parametric locality of the problem and build the efficient iterative scheme reconstructing only a subset of the whole set of parameters in each step. We demonstrate super-resolving reconstruction of grey transmission objects with the experimental data obtained by imaging with entangled twin-photons and pseudo-thermal sources. We predict and experimentally confirm the existence of optimal photon correlations providing for the best image resolution. We also show how an estimation bias may drastically improve the resolution.