Description
Compressive sensing theory is a framework for simultaneously sampling and compressing signals, and it laid the foundation to enable recovery of a compressible signal from incomplete non-adaptive measurements. In recent years, compressive sensing has gained significant popularity in the signal processing community, resulting in many novel imaging and signal acquisition designs, but to date the applications have been mainly in free air space. This project develops a compressive sensing-based imaging system applicable in dispersive medium such as that in turbid coastal conditions. The proposed design uses a Digital Mirror Device (DMD), a spatial light modulator, as the illuminator to project a set of binary random patterns into the water. An electro-optical numerical model EODES is used to predict the actual pattern at the target plane, which is used as the measurement matrix in recovering the imagery using a total variation (TV) minimization-based optimization process.
Such a system design utilizes mature display technology widely used in consumer electronics, and can provide a more compact, reliable, and cost-effective alternative to other highly regarded extended range underwater laser imaging techniques such as the laser line scan system.
The proposed design has performed well in simulations conducted to date.
System architecture of a compressive sensing-based underwater serial laser imager
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Illuminated Pattern |
Att. Len=1 |
Att. Len=5 |
Att. Len=7 |
EODES-predicted measurement matrix at different attenuation lengths
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Att. Len |
LLS |
CS |
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1 |
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5 |
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7 |
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Comparison of simulation image from laser line scan imager and CS-based imager
For more information, please contact Bing Ouyang.
References:
Dalgleish F. R., Ramos, B., Britton, W. B., and Caimi F. M., 2010, “Multistatic distributed laser line scan underwater imaging architecture.” Proc. ONR/NASA Ocean Optics XX. Sept 27th-Oct 1st 2010. Anchorage, AK. Dalgleish, F. R. Caimi, F. M., Vuorenkoski, A. K., Britton, W. B. and Ramos. B., 2009 "Experiments in bistatic Laser Line Scan (LLS) underwater imaging". Proc. MTS/IEEE Oceans 2009, October 26-30 2009, Biloxi. MI.
