Stranica 190 [190]
Match the brightness (luminance) of the IRR and/or UVR image to the calibrated VIS image
7) If processing the IRR and/or UVR images, click on the “specden” tab to the right. The
spectral density correction of the IRR and UVR images is carried out by matching the
luminance of these images to that of the calibrated VIS image (see Workflow for the
correction of IR and/or UV-reflected images and the generation of IR and/or UV¬
reflected false-colour images).
8) Check that the areas being sampled to create the matrix of values for comparison with
the VIS image are within the targets by double left-clicking on the “sample” thumbnail
which opens a window (B9.sample). A slider is provided to adjust this as necessary for
the available Spectralon diffuse reflectance standards, although this should not be
necessary if the position of the targets has not moved significantly between frames and
the alignment procedure was carried out in the previous tab.
Generate the IRR and/or UVR false-colour image
9) If processing the IRR and/or UVR images, click on the “falsecolour” tab to generate the
IRR and/or UVR false-colour images from the calibrated VIS image and the corrected
IRR and/or UVR images (see Workflow for the correction of IR and/or UV-reflected
images and the generation of IR and/or UV-reflected false-colour images).
10) To generate the IRR false-colour image, check that “X-RG” option is selected at K9. To
generate the UVR false-colour image, check that “GB-X” option is selected at K2.
Mathematically reconstruct the ambient stray radiation and subtract it from the UVL and/or
VIL images
11) If processing UVL and/or VIL images, click on the “uvistray” tab (or the “vilstray” tab for
VIL images). This uses the Spectralon diffuse reflectance standards in the UVL (or VIL)
and corresponding VIS images to generate a mathematical reconstruction of the
ambient stray radiation present in the UVL (or VIL) image (for more details see Chapter
1).
12) Check that the areas being sampled to create the matrix of values for use in generating
the mathematical reconstruction are within the targets by double left-clicking on the
“sample” thumbnail which opens a window. A slider is provided to adjust this as
necessary for the available Spectralon diffuse reflectance standards, although this
should not be necessary if the position of the targets has not moved significantly
between frames and the alignment procedure was carried out in the previous tab (see
Workflow for the correction of UV-induced visible luminescence (UVL) images).
Exposure compensation of the UVL image
13) If processing UVL images, the possibility to adjust the exposure (luminance values) of
the UVL image using a slider is provided, so that these are accommodated comfortably
within the sRGB colour space gamut. However this should only be required if any of the
XYZ values of the images in Al are greater than 100. (see Workflow for the
correction of UV-induced visible luminescence (UVL) images).
Version No. 1.0 182 Date : 14/10/2013