Subsampled phase retrieval for temporal resolution enhancement in lensless on-chip holographic video

Abstract

On-chip holographic video is a convenient way to monitor biological samples simultaneously at high spatial resolution and over a wide field-of-view. However, due to the limited readout rate of digital detector arrays, one often faces a tradeoff between the per-frame pixel count and frame rate of the captured video. In this report, we propose a subsampled phase retrieval (SPR) algorithm to overcome the spatial-temporal trade-off in holographic video. Compared to traditional phase retrieval approaches, our SPR algorithm uses over an order of magnitude less pixel measurements while maintaining suitable reconstruction quality. We use an on-chip holographic video setup with pixel sub-sampling to experimentally demonstrate a factor of 5.5 increase in sensor frame rate while monitoring the in vivo movement of Peranema microorganisms.

Dictionary-based phase retrieval for space-time super resolution using lens-free on-chip holographic video

“…The corresponding constraints, i.e., amplitude in Fourier domain and support in object domain, are updated accordingly. Ryu et al [2] reported the issue of space-time resolution tradeoff and proposed a sub-sampled phase retrieval (SPR) scheme for temporal resolution enhancement. Here, we propose a dictionary-based method for further improving the reconstruction results.…”

“…On-chip in-line holography (OIH) is a lens free imaging method that offers high resolution over a wide field-ofview [1,2]. However, high spatial resolution requires longer time for sampling and processing, yielding a low frame rate.…”

“…Our result demonstrates a suitable performance for space-time reconstruction with a temporal increase of 9× with 4 × 4 sub-sampling. Further, we compare phase retrieval performance with previously proposed method, SPR [2]. This dictionary-based super resolution scheme is applicable for monitoring in vivo movement of biological samples, such as Euglena.…”

High-speed holographic imaging using compressed sensing and phase retrieval

“…The second one focuses on lens-free on-chip imaging setup for in vivo scenes of biological samples. 42…”

Lensless imaging through multiple phase patterns illumination

“…[10][11] The resolution of an image is also restricted by sensor pixel sampling due to large pixel size. [12][13][14] In lensless microscopy, this factor is corrected through x − y translation of the illumination source. 8 The lensless microscopic system is made more compact through the side illumination technique 15 to reduce the complexity while achieving a large field of view.…”