Lensless hypercentric imaging using digital holography

Hypercentric imaging is a powerful imaging modality that allows for the inspection of a specimen and its sides in the same recording. Typically, hypercentric imaging involves special lens objectives, which are bulky and limit the use of interferometric methods. To overcome this, we introduce lensless hypercentric imaging utilizing digital holography. We show, that the same hologram can be used to render various digital image perspectives, depending on the size and the position of a virtual aperture. We describe the perspective imaging model in detail and present experimental results, which proof the main concept and exemplarily show the dependence of the image perspective from the position of the aperture. To the best of our knowledge, this is the first time that lensless hypercentric imaging was realized. The results combine the benefits of lensless digital holography with the hypercentric imaging modality, thereby opening a path to a new class of inspection systems.