Optical Data Compression in Time Stretch Imaging

Abstract

Time stretch imaging offers real-time image acquisition at millions of frames per second and subnanosecond shutter speed, and has enabled detection of rare cancer cells in blood with record throughput and specificity. An unintended consequence of high throughput image acquisition is the massive amount of digital data generated by the instrument. Here we report the first experimental demonstration of real-time optical image compression applied to time stretch imaging. By exploiting the sparsity of the image, we reduce the number of samples and the amount of data generated by the time stretch camera in our proof-of-concept experiments by about three times. Optical data compression addresses the big data predicament in such systems.

Adaptive foveated single-pixel imaging with dynamic supersampling

“…In addition, Fig. 5(h-i) also highlights that the number of independently operating fovea can be increased should the scene demand it [24].…”

“…For example, the lack of a fixed Cartesian pixel geometry means it is no longer necessary for the resolution or exposure-time (i.e. the time taken to record all the measurements used in the reconstruction of an image) to remain uniform across the field-of-view, or constant from frame to frame [21][22][23][24]. A variety of animal vision systems successfully employ spatially-variant resolution imaging [25,26].…”

Principles and applications of high-speed single-pixel imaging technology

“…To increase their imaging speed dramatically, a mechanicalscan-free method is a necessity for the generation of structured light patterns. In recent years, an impressive ultrafast optical imaging technique called 'serial time-encoded amplified microscopy (STEAM)' has been proposed, overcoming the compromise between sensitivity and frame rate and achieving real-time observation of fast dynamic phenomena (Goda et al, 2009;2012;Goda and Jalali, 2013;Chen et al, 2015;Lau et al, 2016;Lei et al, 2016). The STEAM technology uses a pulsed laser as the light source and establishes a bridge between the space and time domains using a photonic time stretch (PTS) technique together with spatially dispersive elements.…”

High-throughput label-free image cytometry and image-based classification of live Euglena gracilis

“…In this paper, we demonstrate high-throughput label-free single-cell image cytometry and image-based classification of live E. gracilis cells under different culture conditions. We conduct it with our high-throughput optofluidic image cytometer that builds on an optical time-stretch microscope [5][6][7][8][9][10][11][12][13] with a sub-micrometer resolution of 780 nm at an ultrahigh line rate of 75 Hz [14] combined with an inertial-focusing microfluidic device [15]. The image cytometer enables the acquisition of the images of single cells in a label-free manner without the need for fluorescent probes that can cause interference with cellular functions or bioproduct yield and is, therefore, suitable for monitoring the growth of E. gracilis cells and their response to environmental conditions.…”