Future space based imaging systems require increasingly large aperture sizes to keep pace with the demand for higher spatial resolution for both Earth and Space sciences missions. The cost and weight becomes increasingly prohibitive for telescopes and instruments with apertures greater than 1 meter. A number of solutions are possible and are under investigation; these include: deployable segmented aperture systems, sparse aperture systems, interferometric imaging system, computational deconvolution and super- resolution techniques. The commonality of these techniques lies in increased reliance on sophisticated computational and information theoretic techniques. We give an overview of the complex optical and image processing techniques required for such systems to become operational.