Motion estimation from video for high-throughput lens-less 3D millimeter-wave imaging

Elina B. Richards; Daniel Arnitz; Claire M. Watts; Andreas Pedross-Engel; Matthew S. Reynolds

doi:10.1117/12.2586032

12 April 2021 Motion estimation from video for high-throughput lens-less 3D millimeter-wave imaging

Elina B. Richards, Daniel Arnitz, Claire M. Watts, Andreas Pedross-Engel, Matthew S. Reynolds

Proceedings Volume 11745, Passive and Active Millimeter-Wave Imaging XXIV; 117450A (2021) https://doi.org/10.1117/12.2586032
Event: SPIE Defense + Commercial Sensing, 2021, Online Only

Abstract

Lens-less millimeter-wave (mmWave) imaging of moving objects using a sparse array relies on knowledge of the relative positions between the moving object and the imaging system to enable coherent image reconstruction. However, accurate object position information is rarely available in commercial applications where the moving object, e.g. a conveyor belt or a robot, is controlled independently of the imaging system, or where the imaged objects move autonomously. This poses a significant hurdle for many commercial mmWave imaging applications. We present a video-based motion extraction approach for active mmWave imaging. The object velocity is extracted in real time from motion vectors obtained from a compressed video. This information is combined with readouts from a distance sensor to infer the position of the object at each time instant. Leveraging video-derived motion vectors enables the offloading of computational complexity of 2-D spatial correlations to highly optimized algorithms operating on camera frames. We show experimentally that the image quality of a commercial high-throughput 3-D mmWave imaging system prototype is improved significantly by this approach when the velocity of the target is unknown and time-varying. We furthermore show that image quality is also improved compared to known average motion profiles of the imaged objects. Using a lab setup with known ground truth, we show that the RMS position error is 2.5 mm over a travel length of 0.52 m. This is better than 1/8 of the wavelength at K-band (24 GHz) along the trajectory and thus sufficient to achieve excellent image quality at K-band and longer wavelengths.

Conference Presentation

Citation Download Citation

Elina B. Richards, Daniel Arnitz, Claire M. Watts, Andreas Pedross-Engel, and Matthew S. Reynolds "Motion estimation from video for high-throughput lens-less 3D millimeter-wave imaging", Proc. SPIE 11745, Passive and Active Millimeter-Wave Imaging XXIV, 117450A (12 April 2021); https://doi.org/10.1117/12.2586032

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available