Oldal 40 [40]
Bc A BR 7
ent n" 228
Experimentally, the correction of a luminescence image for the pigment-binder interaction
involves the acquisition of:
(a) a luminescence image (e.g. a UV-induced visible luminescence image)
(b) a reflected image in the spectral range in which the luminescence of interest was
induced (e.g. a UV-reflected image if correcting a UV-induced luminescence image).
Corrected as described.
(c) a reflected image in the same spectral range in which the luminescence of interest was
collected (e.g. a visible-reflected image if correcting a UV-induced visible luminescence
image). Corrected as described.
The corrected images are then subjected to the mathematical operations discussed in more
detail in the Appendix 1 and shown schematically in Figure 1-25 for a UV-induced visible
luminescence image. Summarizing, the three processes are:
1. Calculation of the remission functions for the visible and UV-reflected images, Rem(VIS)
and Rem(UV);
2. Calculation of the y function;
3. Calculation of the corrected luminescence image.
UVR
3
.. (L478.
Rem(7S,)=! a — J
ais, | |
iz R.GB 1
r\2
Remy) - Et )
2UV
Remission Functions
UV-induced Kulbelka-Munk - UV-induced luminescence
luminescence image "ey" Function image corrected for
2 pigment binder effects
ee 1 1
y(VIS,UV) ¬
Rem(I7S ) 1 Rem(I7TS ((Rem(TIS ) -- 2)
Rem(ITS ) + 2 Rem(UTX(Rem(UT)-- 2)
iz RG B
Figure 1-25. Schematic showing the 'pigment-binder' correction of luminescence images using a UV¬
induced luminescence images image of a detail from a wall painting fragment from the British
Museum (Winged youth from the Tomb of the Nasonii, 1883,0505.5) as an example.
Version No. 1.0 32 Date : 14/10/2013