Advertisement
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 |
