A Color Restoration Algorithm for Thin-Film Camera Images

To achieve the demand of earth observation with high spatiotemporal resolution and large scale, a novel optical imaging system is planning to equip on Chinese next generation geo-stationary earth orbit (GEO) satellite. The primary mirror of camera is made of a set of thin films and adopts the diffraction imaging mechanism. A series of ground experiments have been carried out using a thin-film camera with 80 mm aperture for the technical verification. The inherent chromatic aberration due to diffraction imaging appears in the obtained data. To address the issue, a color restoration algorithm by matching, tailoring and linearly stretching the histograms is proposed in this paper. Experimental results show the proposed approach has good performances in color restoration of the diffractive optical images. The effectiveness and robustness of the algorithm are also assessed with various color deviation indexes.