Page 186 - Ming_China_Courts_and_Contacts_1400_1450 Craig lunas

Plate 19.8 Microscopy image of black pigment in BM 1942,0805.1 at Plate 19.9 Microscopy image of red pigment in BL ORB 40/863 at
x200 magnification captured using a Keyence VHX 2000 E series 200x magnification captured using a Keyence VHX 2000 E series
digital microscope digital microscope

a b c
Plate 19.10a–c a) Original RGB image of BL ORB 40/863; b) Black pigment only in LCHLuv L colour space; c) red seal pigment in LCHLuv
C colour space

is a luminance-chrominance colour space which is described been completely separated from the red pigment allowing
by one component representing luminance or ‘lightness’ (L), ease of study of the separate constituents.
and two components representing ‘colour intensity’ (C and The results are impressive. Other imaging techniques
H). It is a direct derivative of the Luv colour space as such as multispectral and hyperspectral imaging will
described earlier. certainly provide a more in-depth analysis of the constituent
Pl. 19.10a shows a digital image of British Library note materials, but these techniques can be expensive to install
ORB 40/863 captured using a Nikon D40 camera. The and require some technical expertise to manage. Colour
image was saved in JPG format in standard RGB colour space analysis is a powerful and affordable method requiring
space and imported into ImageJ, an open source image only a digital image and freely available software.
processing and analysis software package, for colour space
conversion. ImageJ has a plugin architecture which allows Concluding remarks
for extensible programming. Two plugins, Colour The aim of our presentation at the conference was to share
Transformer, and Colour Space Converter, were used in the results of our pioneering research into Ming paper
ImageJ to convert the RGB image of ORB 40/863 (Pl. money. Although the sample of 14 notes was small, the
19.10a) into the LCHLuv colour space. The L and C analysis and imaging were done to the highest specifications
components of this colour space are shown in Pl. 19.10b–c. and the results provide unprecedented data. This data is
The two monochrome images show the black pigment has relevant not only for Ming paper money, but also for Ming

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