We present a series of long-wave-infrared (LWIR) polarimetric-based thermal images of facial profiles in which polarization-state information of the image forming radiance is retained and displayed. The resultant polarimetric images show enhanced facial features, additional texture, and details that are not present in the corresponding conventional thermal imagery. It has been generally thought that conventional thermal imagery (MidiR or LWIR) could not produce the detailed spatial information required for reliable human identification due to the so-called "ghosting" effect often seen in thermal imagery of human subjects. By using polarimetric information, we are able to extract subtle surface features of the human face, thus improving subject identification. The considered polarimetric image sets include the conventional thermal intensity image, S₀ , the two Stokes images, S₁ and S₂, and a Stokes image product called the degree-of-linear-polarization (DoLP) image. Finally, Stokes imagery is combined with Fresnel relations to extract additional 3D surface information.

Date Published: 21 May 2014
PDF: 9 pages
Proc. SPIE 9099, Polarization: Measurement, Analysis, and Remote Sensing XI, 90990G (21 May 2014); doi: 10.1117/12.2049700

Published in SPIE Proceedings Vol. 9099:
Polarization: Measurement, Analysis, and Remote Sensing XI
David B. Chenault; Dennis H. Goldstein, Editor(s)