MOLAB – 2 , Imaging and Diagnosis

Facility type: MOLAB

Access provider: Photonics for Heritage Science, IESL, FORTH

Title: Imaging and Diagnosis


MutliSpectral Imaging (MSI) allows the detailed mapping of the individual layers that compose an artwork using a prototype portable system. The artworks can be studied stratigraphically (differentiating between the individual paint layers), revealing information on their history, composition and structure as well as on their restoration interventions. Information on hidden under-drawings and the series that the pigments were applied allows art historians and scholars to draw conclusions about the period that the artwork was created and the artists’ technique and potentially verify the authenticity of an artwork. Furthermore, the presence of superficial layers and/or retouches contributes to the knowledge and understanding of their history, previous interventions and their preservation state and thus will assist the conservators to decide on the necessary conservation strategies.

Digital Holographic Speckle Pattern Interferometry (DHSPI) permits the non-contact detection of invisible defects and deformations. The method registers deformations by whole-field differential displacement of surface field. DHSPI-I & DHSPI-II are custom-made systems for sensitive interferometric imaging to
capture alterations of surface topography. This technique can be used on various artworks from panel paintings, canvas paintings, furniture, icons, to statues and wall paintings. Additionally, the technique can be used to monitor environmental change impact, transportation effects, restoration and interventive actions impact and originality verification on both movable/immovable artworks.


  • Spectral imaging of painted surfaces for stratigraphic analysis and mapping of materials
  • Monitoring of interventions and evolution of alterations/corrosion
  • Detection of sub-surface defects
  • Monitoring of the impact of environmental fluctuations on objects and monuments
  • Understanding of degradation mechanisms

Technical Info

IRIS II portable MultiSpectral Imaging system. 

IRISI-II is a mobile Spectral Imaging System with 28 interference filters covering the detectors sensitivity range from 350nm-1200nm

  • Sensor: Monochrome CMOS
  • Spectral Sensitivity: 350-1200nm
  • Spectral Bands: 28
  • CCD resolution: 2560*1920 pixels
  • Sensor lens: C-Mount type (exchangeable)
  • Dimensions (LXWXH)
    • Head: 23X16X8.5 cm (overall)
    • Head: 21X16X6.5 cm (overall)

DHSPI-II portable Digital Holographic Interferometry system

DHSPI-II is a compact fully-portable system with dedicated user-friendly software and built-in processing unit for real-time qualitative and post-processed quantitative structural diagnosis. DHSPI-II can be remotely (via cable) controlled  from an external pc (eg laptop) providing extra flexibility for in-situ measurements

  • Laser power:300mW
  • Coherence length: >30m
  • CCD resolution: 2MP
  • Pixel size: 4.40 μm
  • Spatial resolution: 114lines/mm
  • Displacement resolution: 266nm
  • Sensor lens: C-Mount type exchangeable
  • Typical FOV: ≥30 cm, lens depended
  • Beam Divergence: >40cm@1m (Gaussian Profile)
  • Dimensions (LXWXH)
    • Control Unit: 42X26X13 cm.
    • Head: 18X16X8 cm
  • Weight: ≈20 Kgr
  • Peripherals: Tripods, IR Excitation sources, PC


In situ analysis by portable Multispectral Imaging system, IESL, FORTH ©.

In situ analysis by portable Multispectral Imaging system, IESL, FORTH ©.

Related Publications

  • “A method for the registration of spectral images of paintings and its evaluation”, A. Zacharopoulos, K. Hatzigiannakis, P. Karamaoynas, V. M. Papadakis, M. Andrianakis, K. Melessanaki, X. Zabulis, Journal of Cultural Heritage (2017); doi:10.1016/j.culher.2017.07.004
  • “A spectral imaging methodology for determining on-line the optimum cleaning level of stonework”, V. Papadakis, A. Loukaiti, P. Pouli, Journal of Cultural Heritage, 11, 325-328 (2010); doi: 10.1016/j.culher.2009.10.007.
  • “A Novel Hyper-Spectral Imaging Apparatus for the Non-Destructive Analysis of Objects of Artistic and Historic Value”, C. Balas, V. Papadakis, N. Papadakis, A. Papadakis, E. Vazgiouraki, G. Themelis, J. of Cultural Heritage, 4, 330-337 (2003); doi: 10.1016/S1296-2074(02)01216-5.
  • “Complimentarity of digital holographic speckle pattern interferometry and simulated infrared thermography for Cultural Heritage structural diagnostic research”, V. Tornari, M. Andrianakis, K. Hatzigiannakis, K. Kosma, V. Detalle, E. Bourguignon, D. Giovannacci, D. Brissaud, International Journal of Engineering Research & Science ,2, 11, 2395-6992 (2016),
  • “Synchronized deformation monitoring in laser cleaning: an application for Cultural Heritage conservation” V. Tornari, E. Bernikola, K. Hatzigiannakis, K. Melessanaki, P. Pouli, Universal Journal of Physics and Application 1(2): 149-159, (2013); doi:10.13189/ujpa.2013.010215.
  • “Micro-mapping of defect structural micro-morphology in the documentation of fresco wall paintings”, V. Tornari, E. Bernikola, E. Tsiranidou, K. Hatzigiannakis, M. Andrianakis, V. Detalle, J.L. Bodnar, International journal of heritage in the digital era, 2 (1) (2013); doi: 10.1260/2047-4970.2.1.1.

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