Sparse optical interferometric arrays of many apertures can produce direct images in thedensified-pupil mode, also called “hypertelescope” mode. Pending the introduction ofadaptive optics for cophasing, indirect images can also be reconstructed with speckleimaging techniques. But adaptive phasing is preferable, when a sufficiently bright guidestar is available. Several wave sensing techniques, by-products of those used onmonolithic telescopes for some of them, are potentially usable. For cophased direct imagesof very faint sources in the absence of a natural guide star, a modified form of the LaserGuide Star techniques demonstrated on conventional and segmented telescopes is described.Preliminary testing in laboratory suggests further investigation. Recorded images, assumedco-phased, are also improvable post-detection with optical aperture-synthesis techniquessuch as Earth rotation synthesis, where data from successive exposures are combinedincoherently. Nevertheless, the gain becomes modest if hundreds of sub-apertures are used.Image deconvolution techniques are also applicable, if suitably modified as demonstratedby Aime et al. (2012), and Mary(2012). Their modified deconvolution algorithmscan extend the Direct Imaging Field (also called Clean Field) of hypertelescopes. Moresub-apertures at given collecting area, implying that their size is reduced, improve thedirect-imaging performance. The predictable trend thus favors systems combining hundredsof sub-apertures of modest size, if workable designs can be evolved. One such design, the“Ubaye Hypertelescope” entering the initial testing phase in the southern Alps, has afixed spherical meta-mirror with a 57 m effective aperture, expandable to 200 m.Preliminary results suggest that larger versions, whether spherical or activeparaboloidal, can reach a kilometric aperture size at terrestrial sites having a suitableconcave topography. In space, hypertelescope meta-apertures spanning up to 100 000 km arein principle feasible in the form of a flotilla of mirrors, driven by micro-thrusters orby the radiation pressure of the Sun or lasers.