Fig 1.
Schematic representation of theTRICLOBS sensor suite layout.
The long-wave part of the incoming radiation is reflected into an uncooled infrared microbolometer by a LWIR (hot) mirror, the near-infrared part is reflected by a dichroic beam splitter (NIR mirror) towards an image intensifier (ICU), while the visual part goes straight to a second image intensifier.
Fig 2.
(a) The system is contained in a water and dust resistant housing with a single aperture and built-in displays that enable signal monitoring. (b) The interior showing the sensors and other components. (c) The TRICLOBS system mounted on an all-terrain platform.
Fig 3.
(a) Daylight color reference image. Visible (b) and NIR (c) images of the same scene as in (a). (d) Two-band (RG) false-color image obtained by assigning (b) to the green and (c) to the red channel of an RGB color image. The blue channel is set to zero. (e) The color mapping derived from corresponding pixel pairs in (a) and (d). (f) Result of the application of the mapping scheme in (d) to the false-color image in (d).
Table 1.
Brief description of the scenarios represented in the TRICLOBS database.
Fig 4.
Example RGB false-color frame and its individual channels (from scenario TRI_A1).
False-color RGB frames in the TRICLOBS database (a) are constructed by mapping corresponding (b) Visual frames to the Red channel, (c) NIR frames to the Green channel and (d) LWIR frames to the Blue channel of an RGB color image.
Fig 5.
Example MP4 movie frame (from TRI_A1.mp4).
The MP4 movies consist of four panels: the lower three panels represent the Visual (left), NIR (middle) and LWIR (right) channels, while the upper panel shows the fused result after color remapping performed on the TRICLOBS system.
Fig 6.
Example of grayscale image fusion.
(a) False-color frame from series TRI_B1, with the Visual (R) channel (b), the NIR(G) channel (c) and the LWIR (B) channel (d). (e) Result of grayscale (Laplacian pyramid) fusion of (b-d). The person carrying a box behind the glass door is quite distinct in the Visual band but not represented in the LWIR band. In contrast, smoke from the chimney on the upper left is quite distinct in the LWIR band but not represented in the other bands.
Fig 7.
Example of grayscale image fusion.
(a) False-color frame from series TRI_B2 with the Visual (R) channel (b), the NIR(G) channel (c) and the LWIR (B) channel (d). (e) Result of grayscale (Laplacian pyramid) fusion of (b-d). The person emerging from the foliage and the smoke plume rising from the chimney on the left are both highly visible in the LWIR band (d) but hard to distinguish in the other two bands. Both these details are represented with high contrast in the grayscale fused image (e) that is obtained through Laplacian pyramid fusion of the three individual bands.
Fig 8.
Example of grayscale image fusion.
(a) False-color frame from series TRI_C3 with the Visual (R) channel (b), the NIR(G) channel (c) and the LWIR (B) channel (d). (e) Result of grayscale (Laplacian pyramid) fusion of (b-d). The persons behind the two upper windows in the house on the foreground (left) and the two soldiers in front of the hedge in the back are visible in different bands but are all represented in the fused image (e).
Fig 9.
Color remapping applied to false-color RGB frames from the TRICLOBS data set.
Applying a color remapping (defined by the color table pair a,b) to RGB false-color frames (c, e and g) gives them a realistic color appearance (d, f and h).