An assessment of multimodal imaging of subsurface text in mummy cartonnage using surrogate papyrus phantoms

Heritage Science

Table 1 Comparison of different imaging modalities

Imaging technique	Number of sheets through which iron-based inks can be recorded	Number of sheets through which carbon-based inks can be recorded	Typical image acquisition time	Typical image processing time	Pixel/voxel size	Field of view
Multispectral imaging	2	2	20 min	~ 1 h	24 μm	30 × 30 cm
Transillumination	> 3	> 3	20 min	~ 1 h	24 μm	10 × 15 cm
Optical coherence tomography	0	0	< 10 s	2 min	2 μm	10 mm × 2 mm (in depth)
X-ray micro tomography	> 3	Not visible	18 h	< 2 h	38 μm	5 × 10 cm
Portable X-ray fluorescence spectroscopy	6	Not visible	30 s	None	~ 1 cm	1 cm
X-ray fluorescence imaging	> 3	Not visible	10 s	1 min	100 μm	10 × 15 cm
X-ray phase contrast imaging	> 3	Not visible	10 min	1 min	100 μm	2 × 5 cm
Terahertz	1	3	0.1 s/pixel	10–20 s	100 μm	4 × 4 cm

Note that for most of these parameters can be varied depending on the application, so these figures should be seen as indicative only