Spectral Imaging
The ISAAC Research Centre has developed a series of versatile and modular spectral imaging systems that enable automated high spatial resolution imaging from remote distances of tens of metres (80 micron resolution at distance of 10m) to close range imaging in the microscopic mode (a few micron resolution), from hyperspectral to broad band imaging.
Reflectance spectra can be collected alongside the imaging function, creating the opportunity to compare and identify the materials present- in a heritage context, this is most often used for pigment identification.
Reflectance Spectral Imaging:
-
enables automated high spatial resolution imaging from close range to remote distances of tens of metres (80-micron resolution at distance of 10 m),
-
efficiently collects millions of reflectance spectra in one image cube (2D spatial and wavelength in the 3rd dimension),
-
uses automated scanning to collect images and data from a large area.
The automated scanning functionality of the technique is particularly suited to the analysis of large decorated surfaces such as murals and decorated architectural sites such as churches- these applications are discussed on our Remote Sensing page.
The spatial and spectral parameters of the ISAAC Lab's spectral imaging systems are shown below.

Short wave infrared (SWIR) spectral imaging of the decoration on the Macedonian tomb at Aghios Athanasios, Greece, during our 2023 Molab analysis visit




In situ spectral imaging of the Canterbury Roll in New Zealand, 2018.
applications of spectral imaging
-
Revealing underdrawings on paintings and drawings using the imaging functionality
-
Pigment identification by collection of reflectance spectra during the analysis
isaac instrumentation
Micro-level Spectral Imaging
System
VIS-NIR hyperspectral imaging
Developer
ISAAC Lab
Spectral Range
400-1000 nm
Spectral Resolution
2.8 nm
Maximum Spatial Resolution
3 µm
Working
Distance
30 mm
Service
MOLAB/
FIXLAB
Close Range Spectral Imaging
System
Close Range
VIS-NIR Hyperspectral Imaging
VIS-NIR
miniature Hyperspectral imaging
(SPECIM-IQ)
Close-Range SWIR Hyperspectral Imaging
Close-Range VIS-NIR Spectral Imaging (PRISMS)
Mid-Infrared (MIR) Imaging
Developer
ISAAC Lab
SPECIM
NEO
ISAAC Lab
FLIR
Spectral Range
400- 1000 nm
400- 1000 nm
930- 2500 nm
400- 850 nm
1500- 5000 nm
Spectral Resolution
2.8 nm
7 nm
5.5 nm
50 nm
600- 2000 nm
Working
Distance
20 cm
15- 50 cm
10 cm
1.5- 20 m
1- 3 m
Service
MOLAB/
FIXLAB
MOLAB/
FIXLAB
MOLAB/
FIXLAB
MOLAB/
FIXLAB
MOLAB/
FIXLAB
Ground- based Remote Imaging
System
Remote VIS-NIR Spectral Imaging
Remote VIS-NIR Hyperspectral Imaging
Remote SWIR Hyperspectral Imaging
Developer
ISAAC Lab
ISAAC Lab
ISAAC Lab/
Neo
Spectral Range
400 nm – 850 nm
400 – 1000 nm
930 – 2500 nm
Spectral Resolution
50 nm
2.8 nm
5.5 nm
Maximum Spatial Resolution
60 µrad
30 µrad
45 µrad
Working
Distance
> 1.5 m
> 3.5 m
> 3.5 m
Service
MOLAB/
FIXLAB
MOLAB/
FIXLAB
MOLAB/
FIXLAB
Airborne Remote Spectral Imaging
System
UAV-based VIS/NIR Hyperspectral Imaging + LIDAR system
(UAV LIDAR-HSI)
Developer
Headwall
Spectral Range
400 nm – 1000 nm
Spectral Resolution
2.2 nm
Working
Distance
> 10 m
Service
MOLAB
Hybrid OCT and Spectral Imaging System
ISAAC Hybrid OCT System:
Developer
OCT Depth Resolution (air/polymer)
OCT Transverse Resolution
Working Distance
Spectral Imaging Spectral Range
Spectral Imaging Spectral Resolution
Spectral Imaging Transverse Resolution
Hybrid OCT @ 1350 nm &
VIS/NIR Microscopic Spectral Imaging
ISAAC Lab
5 µm / 3.3 µm
10 µm
40 mm
415 nm – 845 nm
10 nm
5 µm
selected publications
This is a selection of our Spectral Imaging publications. Our full publication list can be found here.
Liggins, F., Vichi, A., Liu, W., Hogg, A., Kogou, S., Chen, J. & Liang, H., 2022. Hyperspectral Imaging Solutions for the Non-Invasive Detection and Automated Mapping of Copper Trihydroxychlorides in Ancient Bronze. Heritage Science 10, 142. https://doi.org/10.1186/s40494-022-00765-8
Kogou, S., Li, Y., Cheung, S., Han, N., Liggins, F., Shahtahmassebi, G., Thickett, D. and Liang, H. 2025 Ground-Based Remote Sensing and Machine Learning for in Situ and Noninvasive Monitoring and Identification of Salts and Moisture in Historic Buildings. Analytical Chemistry 2025 https://doi.org/10.1021/acs.analchem.4c05581
Kogou, S., Shahtahmassebi, G., Lucian, A., Liang. H, Shui, B., Zhang, W., Su, B. and van Schaik, S. 2020. From remote sensing and machine learning to the history of the Silk Road: large scale material identification on wall paintings. Sci Rep 10, 19312 (2020). https://doi.org/10.1038/s41598-020-76457-9
Read, M., Cheung, C.S., Ling, D., Korenberg, C., Meek, A., Kogou, S. and Liang, H., 2019. A Non-Invasive Investigation of Limoges Enamels using both Optical Coherence Tomography (OCT) and Spectral Imaging: A Pilot Study. In: H. Liang and R. Groves, eds., Optics for Arts, Architecture, and Archaeology Vii. SPIE Optical Metrology, Munich, Germany, 24-27 June 2019. SPIE Proceedings 11058, 1105803 https://doi.org/10.1117/12.2527092
Wijsman, S., Neate, S., Kogou, S., Liang, H., 2018. Uncovering the Oppenheimer Siddur: using Scientific Analysis to Reveal the Production Process of a Medieval Illuminated Hebrew Manuscript. Heritage Science 6, 15. https://doi.org/10.1186/s40494-018-0179-0
Kogou, S., Neate, S., Coveney, C., Miles, A., Boocock, D., Burgio, L., Cheung, C.S. and Liang, H., 2016. The Origins of The Selden Map of China: Scientific Analysis of the Painting Materials and Techniques Using a Holistic Approach. Heritage Science, 4, 18. https://doi.org/10.1186/s40494-016-0098-x
