CARL Database

Visible and thermal images have been acquired using a thermographic camera TESTO 880-3, equipped with an uncooled detector with a spectral sensitivity range from 8 to 14 μm and provided with a germanium optical lens, and an approximate cost of 8.000 EUR. For the NIR a customized Logitech Quickcam messenger E2500 has been used, provided with a Silicon based CMOS image sensor with a sensibility to the overall visible spectrum and the half part of the NIR (until 1.000 nm approximately) with a cost of approx. 30 EUR. We have replaced the default optical filter of this camera by a couple of Kodak daylight filters for IR interspersed between optical and sensor. They both have similar spectrum responses and are coded as wratten filter 87 and 87C, respectively. In addition, we have used a special purpose printed circuit board (PCB) with a set of 16 infrared leds (IRED) with a range of emission from 820 to 1.000 nm in order to provide the required illumination.

The thermographic camera provides a resolution of 160×120 pixels for thermal images and 640×480 for visible images, while the webcam provides a still picture maximum resolution of 640×480 for near-infrared images and this has been the final resolution selected for our experiments.

A couple of halogen focus disposed 30 degrees away from the frontal direction and about 3 m away from the user, match the artificial light of the room. Note that all the tripods and structures have fixed markings on the ground.