4,175 research outputs found
Simultaneous real-time visible and infrared video with single-pixel detectors
Conventional cameras rely upon a pixelated sensor to provide spatial resolution. An alternative approach replaces the sensor with a pixelated transmission mask encoded with a series of binary patterns. Combining knowledge of the series of patterns and the associated filtered intensities, measured by single-pixel detectors, allows an image to be deduced through data inversion. In this work we extend the concept of a ‘single-pixel camera’ to provide continuous real-time video at 10 Hz , simultaneously in the visible and short-wave infrared, using an efficient computer algorithm. We demonstrate our camera for imaging through smoke, through a tinted screen, whilst performing compressive sampling and recovering high-resolution detail by arbitrarily controlling the pixel-binning of the masks. We anticipate real-time single-pixel video cameras to have considerable importance where pixelated sensors are limited, allowing for low-cost, non-visible imaging systems in applications such as night-vision, gas sensing and medical diagnostics
Terahertz dynamic aperture imaging at stand-off distances using a Compressed Sensing protocol
In this text, results of a 0.35 terahertz (THz) dynamic aperture imaging
approach are presented. The experiments use an optical modulation approach and
a single pixel detector at a stand-off imaging distance of approx 1 meter. The
optical modulation creates dynamic apertures of 5cm diameter with approx 2000
individually controllable elements. An optical modulation approach is used here
for the first time at a large far-field distance, for the investigation of
various test targets in a field-of-view of 8 x 8 cm. The results highlight the
versatility of this modulation technique and show that this imaging paradigm is
applicable even at large far-field distances. It proves the feasibility of this
imaging approach for potential applications like stand-off security imaging or
far field THz microscopy.Comment: 9 pages, 13 figure
Fast Compressive 3D Single-pixel Imaging
In this work, we demonstrate a modified photometric stereo system with perfect pixel
registration, capable of reconstructing continuous real-time 3D video at ~8 Hz for 64 x 64 image resolution by employing evolutionary compressed sensing
Non-invasive, near-field terahertz imaging of hidden objects using a single pixel detector
Terahertz (THz) imaging has the ability to see through otherwise opaque
materials. However, due to the long wavelengths of THz radiation
({\lambda}=300{\mu}m at 1THz), far-field THz imaging techniques are heavily
outperformed by optical imaging in regards to the obtained resolution. In this
work we demonstrate near-field THz imaging with a single-pixel detector. We
project a time-varying optical mask onto a silicon wafer which is used to
spatially modulate a pulse of THz radiation. The far-field transmission
corresponding to each mask is recorded by a single element detector and this
data is used to reconstruct the image of an object placed on the far side of
the silicon wafer. We demonstrate a proof of principal application where we
image a printed circuit board on the underside of a 115{\mu}m thick silicon
wafer with ~100{\mu}m ({\lambda}/4) resolution. With subwavelength resolution
and the inherent sensitivity to local conductivity provided by the THz probe
frequencies, we show that it is possible to detect fissures in the circuitry
wiring of a few microns in size. Imaging systems of this type could have other
uses where non-invasive measurement or imaging of concealed structures with
high resolution is necessary, such as in semiconductor manufacturing or in
bio-imaging
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