WG 1: Spectral object documentation

Leader: Dr. Marcello Picollo (IT), vice-leader: Sérgio Nascimento (PT)

1st WG task st1.1 Identification, characterization and testing of spectral imaging techniques in the visible and near IR field
Spectral imaging techniques undergo a comparable change in technology as do spatial imaging techniques.
New developments in optical techniques lead to new means of splitting light resulting in new characteristics for instruments dedicated to monitor the optical spectrum for imaged surfaces. It is therefore necessary to explore the limits and advantages of the actual instruments in this waveband.

2nd WG task st1.2 Identification, characterisation and testing of imaging techniques beyond the visible and short wave radiation
The physical and chemical composition of surfaces is an important factor determining the interaction with light and reflection behaviour. As not all of these factors have an impact in the visible spectrum, instruments exist which are able to measure beyond this radiation. It is necessary to exploit and qualify also these type of instruments because they are often essential for the analysis of the surface composition.


The activities of COSCH WG1 are mainly focussed on the identification, characterisation and testing of two dimensions (2-D) spectral imaging techniques in the visible and near infrared (IR) field (task st1.1) and on the identification, characterisation and testing of imaging techniques beyond the visible and short wave radiation (task st1.2) for the study and documentation of CH artefacts. These tasks brought together research groups with different backgrounds and diverse research applications and aims. However, most of the efforts have been dedicated to the application of spectral imaging techniques to the investigation of artworks, mainly 2-D objects such as paintings.


2016 meetings/events:

  • WG1 task force meeting in Florence (IT), March 2016

Task Force Meeting – Florence (IT) 10.03.2016 - Istituto di Fisica Applicata "Nello Carrara", CNR

Attending: Andrea Casini (IT), Costanza Cucci (IT), Sony George (NO), João Linhares (PT), Lindsay MacDonald (UK), Cristina Montagner (PT), Sérgio Nascimento (PT), Marcello Picollo (IT), Ruven Pillay (FR), Armonie Sauzet (FR), Lorenzo Stefani (IT), Tatiana Vitorino (PT), E. Keats Webb (UK)

Participants of the Task force meeting at IFAC-CNR.

Presentation by Marcello Picollo to introduce the objectives of the meeting:

  • To discuss about the outcomes of the RRT
  • To discuss possible participation in COSCH book
  • To complete a reference list on different techniques/spectral regions
  • To complete a glossary a terms

Participants listening to Picollo's presentation.

Presentation by E. Keats Webb to present the Round Robin Test experience:

  • Introduction of the test objects
  • Short description of the STSMs developed
  • Current state of the data, including a summary of multi- and hyper-spectral systems, institutions, and users involved, and the challenges and issues associated with the data
  • Future work, including receiving the data that is still missing, further research and processing of data, and creation of guidelines and best practices

Webb presenting the RRT experience.

Open discussion to decide how to obtain results from the RRT to write the final report:

  • Selection of groups/people to work on the multispectral RRT data
  • Definition of tasks and questions that the participating institutions should carry out and answer
  • Dissemination through conferences and COSCH book
  • Distribution of tasks to complete the references list and glossary

Visit to IFAC-CNR's imaging spectroscopy laboratory at the end of the meeting.



2015 meetings/events:

  • Autumn WG meeting - Neuchâtel (CH), October 2015
  • CAA 2015, COSCH Special Session in Sienna (IT), April 2015
  • Spring MC&WG Meeting - Saint Etienne (FR), March 2015
  • CCIW'15, COSCH Special Session in Saint Etienne (FR), March 2015

WG1 has been actively involved in discussing the following themes:
1. Standardising the acquired imaging data and the calibration procedures to be followed with the diverse imaging systems.
2. Creating a well-defined and structured Round Robin Test (RRT) in order to compare colour and spectroscopic measurements, as well as information on calibration standards and laboratory mock-ups obtained through the use of diverse imaging devices developed by the different research groups that participate in the COSCH Action.
3. Exploring the possibilities offered by different technical and methodological approaches for the acquisition of multi- and hyper-spectral imaging data.
4. Implementing knowledge, guidelines, good practices and standardised methodologies with respect to the application of the numerous spectral imaging devices used to study and document cultural heritage.

Autumn WG Meeting – Neuchâtel (CH), 13.10.2015 - Haute Ecole Arc Conservation-restauration, Campus Arc 2

Attending: Irina Ciortan (RO), Sony George (NO), Jon Yngve Hardeberg (NO), J. Jussila (FI), João Linhares (PT), Lindsay MacDonald (UK), Sérgio Nascimento (PT), Marcello Picollo (IT), Ruven Pillay (FR), E. Keats Webb (UK)

STSM invited presentation dealing with WG1 activities

  • E. Keats Webb: "COSCH STSM WG1: Elaboration of Hyperspectral Image Data from Round Robin Test Acquisition"

Participants of the WG1 meeting at the COSCH Neuchâtel autumn meeting.

WG1 meeting Summary

  • Agreement letter: Hardcopy of letter getting passed around
  • RRT experience (completed by, data shared by, calibrated data shared by)
  • Processing RRT data

M. Picollo—panel painting
L. MacDonald—icon
S. George and I. Ciortan—color chart
R. Pillay—Involvement with VNIR hyperspectral data

  • Reports

STSM on RRT objects

COSCH report on WG1 activities

  • RRT data published on ISI scientific journal with IF. Use Andras Jung paper as model to structure our paper
  • Reference lists on different techniques/spectral regions: list and pdf files
  • Glossary: Still a little unclear about what is wanted/needed for the COSCH Glossary

CAA 2015, COSCH Special Session in Sienna (IT), 31.03.15

At the 43rd Computer Applications and Quantitative Methods in Archaeology conference (CAA 2015), Siena (Italy), March 30 - April 3 2015, COSCH supported a special session on colour in cultural heritage, chaired by Anna Bentkowska-Kafel, to which two oral and one poster presentations from the action's community were selected. The oral presentations dealt with the application of hyper-spectral imaging techniques to the investigation of concealed layers of paintings, mainly covering the WG1 activities, and of 3D technologies for the documentation of ancient Roman coins. The session testified the strong interest from scientists and researchers with different cultural backgrounds (museum professionals, archaeologists, art historians, digital humanities scholars) in the application of 2D and 3D spatial and spectral documentation of material cultural objects.

Spring MC&WG Meeting – Saint Etienne (FR), 26-28.03.2015 - Telecom Engineer School, University Jean Monnet

Attending: Corinna Ludovica Kock Dandolo (DK), Elodie Herens (BE), Irina Ciortan (RO), Jaroslav Valach (CZ), Julio M. del Hoyo Melendez (PL), Lindsay MacDonald (UK), Manfred Schreiner (AT), Marcello Picollo (IT), Raju Shresthat (NO), Ruven Pillay (FR), Sérgio Nascimento (PT), Sony George (NO), Tatiana Vitorino (PT), Vera Moitinho de Almeida (CY)

Invited presentation dealing with WG1 activities

  • Corinna Ludovica Koch Dandolo: "Terahertz Time-Domain Imaging for Imaging Analysis of Panel Paintings"

WG1 meeting Summary

Round Robin Test (most of the time of the meeting was dedicated to this crucial point)

  • The project manager (S. George) continues organising the RRT and makes sure that all the participating groups will follow the defined time-schedule.
  • It was decided to nominate a person to be responsible for each specific topics/objects, in order to facilitate the organisation and management of the data.
  • I. Ciortan and S. George were responsible for managing data related to the X-Rite ColorChecker chart.
  • L. MacDonald became responsible for the icon's data.
  • M. Picollo and T. Vitorino were in charge of the data concerning the painted panel.
  • S. Nascimento suggested that there should be a written agreement between all the research groups involved in the RRT to avoid any eventual legal problems and to clarify to all participants what is being done within the Round Robin exercise and what are its purposes.

(left) Picollo's talk on "Presentation of WG1 Outputs"; and (right) Picollo and Nascimento (WG1 Leader and Vice-Leader) during the coffee break at the COSCH MC & WG, Spring 2015 St. Etienne Meeting.

CCIW'15, COSCH Special Session in Saint Etienne (FR), 26.03.2015

At the 5th Computational Color Imaging Workshop (CCIW 2015), Saint Etienne (France), March 24 - 26 2015, COSCH supported a special session on colour in cultural heritage. The session was mostly related with digitisation and visualisation of cultural heritage objects, and it was well attended by researchers with different backgrounds. COSCH was represented by two invited and two oral presentations on colour accuracy the conference was a successful opportunity for promoting the action's activities.


09h00 – 10h00. Invited Speaker: Zoltan Kao, University of Szeged (Hungary), "Relative pose estimation and fusion of 2D spectral and 3D lidar images"

10h00 – 10h30. Coffee Break

Oral session
10h30 - 11h00. Jay Arre Toque, Pengchang Zhan, Peng Wang, Ari Ide-Ektessabi (Japan), "High-resolution multispectral scanning for mesoscopic investigation of discoloration of traditional Japanese pigments"
11h00 - 11h30. Citlalli Gámez Serna, Alain Trémeau, Ruven Pillay (France), "Data fusion of objects using techniques such as Laser Scanning, Structured Light and Photogrammetry for Cultural Heritage Applications"
11h30 - 12h00. Tatiana Vitorino, Andrea Casini, Costanza Cucci, Ana Gebeje, Jouni Hiltunen, Markku Hauta-Kasari, Marcello Picollo, Lorenzo Stefani (Italy & Finland), "Accuracy in colour reproduction: using a ColorChecker chart to assess the usefulness and comparability of data acquired with two hyper-spectral systems"
14h00 - 15h00. Invited Speaker: Lindsay McDonald, University College London (UK), "Representation of cultural heritage objects by image sets with directional illumination"

Oral session
15h00 - 15h30. Sérgio M.C. Nascimento, João M.M. Linhares, Catarina A. R. João, Kinjiro Amano, Cristina Montagner, Maria J. Melo, Marcia Vilarigues (Portugal), "Estimating the colors of paintings"


2014 meetings/events:

  • WG1 Training School in Florence (I), December 2014
  • Belgrade meeting (RS), September 2014
  • WG1 - ICISP Special Session in Cherbourg (F), June-July 2014
  • Task force meeting in Cherbourg (F), June 2014
  • Joensuu meeting (FIN), March-April 2014
  • Task force meeting in Braga (P), January 2014

WG1 Training School in Florence (IT), 10-12.12.2014

The 2014 COST-COSCH Training School on "Hyperspectral imaging – Techniques applied to the investigation of 2D polychrome surfaces" was organised in Florence by the IFAC-CNR Applied Spectroscopy research group. The idea of the Training School was to provide a general overview of hyper-spectral technologies for artworks investigations, mainly paintings. The program was multidisciplinary and took into consideration different approaches to the topic in order to meet the needs of the diverse professionals working in and competences applied to this field.

The class included 16 participants, who had different backgrounds and came from various European countries, which resulted in a wide representation of fields and nationalities, thus making it a multi-disciplinary group inclined to discuss and exchange ideas on the application of hyper-spectral imaging techniques to the investigation of paintings and other art objects.

The IFAC-CNR organizing Committee: Marcello Picollo, Costanza Cucci, Andrea Casini, Lorenzo Stefani, Filippo Micheletti, Eva Mariasole Angelin, Carlotta Stevani

Participants of the Training School at the Museum of San Marco, Florence.

Participants of the Training School listening to Costanza Cucci's presentation on 2-D hyper-spectral imaging devices and data acquisition.

Visit of the restoration laboratories of the SSPSAE e per il polo museale della città di Firenze, Florence, guided by Marina Ginanni and Elena Prandi.


Fall MC Meeting – Belgrade (RS) 15-17.09.2014 - Mathematical Institute of the Serbian Academy of Sciences and Arts and Faculty of Mathematics

Attendees: I. Ciortan (RO), A. Gebejes (FI), S. George (NO), J. Hoyo Melendez (PL), M. Picollo (IT), T. Vitorino (PO)

Presentation: M. Picollo: "Limits and advantages of different 2D VIS-NIR spectral imaging systems in answering conservators' questions".

The first RRT results were reported and more laboratories decided to join the RRT experience.

As defined in Belgrade the laboratories participating to the RRT were

1) University of Eastern Finland, Joensuu, Finland

2) UCL London, UK

3) Gjovik University Norway

4) IFAC-CNR, Florence, Italy

5) Imaging & Media Lab, Universität Basel, Switzerland

6) University of Leipzig, Germany

7) University of Minho, Braga, Portugal

8) CD6-UPC Terrassa, Barcelona, Spain

9) Museum in Krakow, Poland

10) Centre de Recherche et de Restauration des Musées de France Musée du Louvre, Paris, France

11) Norsk Elektro Optikk AS, Norway

12) Institute of Theoretical and Applied Mechanics of the Academy of Sciences, Prague, Czech Republic

13) University of Burgundy, France

14) University of Milan-Bicocca, Italy


2nd WG1 Task-Force Meeting - Cherbourg (FR) 30.06.2014 - IUT Cherbourg Manche

Attendees: F. Deger (NO), F. J. Burgos (ES), P. Fält (FI), M. Flinkman (FI), A. Gebejes (FI), S. George (NO), M. Hauta-Kasari (WG1 chair, FI), A. Karmacharya (DE), L. MacDonald (UK), A. Mansuri (local-organizer, FR), C. Montagner (PO), M. Picollo (WG1 vice-chair, IT), J. Sakamoto (FI), M. Vilaseca (ES), T. Vitorino (PO), S. Wefers (DE).

Participants of the task-force at the end of the meeting. A. Mansouri is not present in the picture due to his ICISP conference organisation responsibilities; S. George was looking for Mansouri; while P. Fält, M. Flinkman, A. Gebejes, and J. Sakamoto were attending on-going sessions.

Discussion about the Round Robin Test objects and their ongoing measurements:

  • Round Robin Test 1: X-Rite® ColorChecker Classic (provided by M. Hauta-Kasari);

ColorChecker chart (280 mm x 216 mm) to define the characteristic of each imaging device in colour rendering.

  • Round Robin Test 2: X-Rite® White Balance (provided by M. Hauta-Kasari);

White Balance chart (280 mm x 216 mm) to define the level of homogeneity in illumination during the image acquisition and in detector elements.

  • Round Robin Test 3: SphereOptics Zenith Polymer Wavelength Standard Calibration Standard (provided by A. Jung);

New reference panel of PTFE mixed with rare earth elements (erbium, dysprosium and holmium) to define the spectral accuracy and resolution of each imaging device.

  • Round Robin Test 4: Antique Russian icon (1899) printed on copper plate glued to a wooden support (provided by L. MacDonald);

Russian icon (265 mm x 220 mm) representing the "Virgin of Kazan" and marked Moscow 1899, to stress the behaviour of the different imaging device when highly reflective surfaces, such as gold background, are investigated.

  • Round Robin Test 5: test panel painted with medieval Tuscan technique (provided by M. Picollo).

Tempera painting mock-up with gypsum/canvas/gypsum ground on wood, made by conservators at the Restoration Laboratories of the Soprintendenza Speciale per il Patrimonio Storico, Artistico ed Etnoantropologico e per il Polo Museale della città di Firenze, to highlight the performances of the different imaging devices in penetrating the paint layers and detecting the under-drawings.

Results of the WG1 Taskforce Meeting in Cherbourg

  • Presentations of the selected five objects and the purpose of their investigation with special focusses on the application in the art/archaeological conservation fields.
  • Definition of possible connections with WG2 to link 3D with multi- and hyper-spectral imaging data.
  • Presentation of the RRT results to conservation (art and archaeology) field experts and colour conference, such as AIC and CAA.
  • Having end-users to test the results produced by the RRT and co-authoring join papers to be published on conservation and conservation-science journals.


Spring MC Meeting – Joensuu (FI) 31.03-01.04.2014 – University of Eastern Finland

Attendees: J. del Hoyo Melendez (PL); H. Skjerping, R. Shrestha, S. George (NO); T. Saarinen, T. Saarinen, M. Hauta-Kasari, H. S., J. Sakamoto (FI); D. Rieke-Zapp (DE); L. MacDonald (UK); A. Mansouri (FR); J. Linhares, S. Nascimento, T. Vitorino (PO); M. Picollo (IT); B. Marinkovic (RS); D. Strivay (BE)

STSM 2013 invited presentation dealing with WG1 activities

  • Tatiana Vitorino: "Hyper-spectral Acquisition on Historically Accurate Reconstructions of Red Organic Lakes"

WG1 meeting Summary

Round robin test (most of the time of the meeting was dedicated to this crucial point)

  • The project manager (S. George, Norway) will continue organising the RRT and make sure that all the participating groups will follow the defined time-schedule.
  • Update on the data acquisition parameters and expected results (fine tuning and more details).
  • Testing of samples is underway. There is a need for people that will be responsible for analysing and evaluating the dataset.
  • The dataset will be available as supplementary material on a paper or a central website that supports raw data in various formats.
  • Handling and transporting protocol for the icon as well as data delivery proposals.

STSM call for proposals: specific announcement for a candidate or candidates with experience in analysis and evaluation of HSI data (support person for RR testing).


1st WG1 Task-Force Meeting - Braga (PO) 27-28.01.2014 - Minho University; Dept. of Physics

Attendees: F. Boochs (DE); F.J. Burgos (ES); S. George (NO); J. Linhares (PO); L. MacDonald (UK); S. Nascimento (PO); M. Picollo (IT); H. Skjerping (NO).

Participants of the task-force meeting during the guided tour of the Colour Science Laboratory offered by Sérgio Nascimento.

Presentations of the activities of the groups participating at the meeting:

  • Sérgio Nascimento, Colour Science Laboratory, Uminho: "Applications of spectral imaging in art and cultural heritage"
  • Marcello Picollo, Applied Spectroscopy Lab., IFAC-CNR: "Fiber Optic Reflectance Spectroscopy (FORS) and Hyper-spectral Imaging (HSI) Techniques applied to the analysis of polychrome surfaces"
  • Antonio Cardoso, Signinum Restoration Company: "Syddarta Project"
  • Francisco J. Burgos, Centre for Sensors, Instruments and Systems Development (CD6), UPC: "Spatial and spectral object reconstruction at the CD6"
  • Lindsay MacDonald, Photogrammetry, 3D Imaging and Metrology Research Centre, UCL: "Using Filters in Multispectral Imaging"
  • Sony George, The Norwegian Colour and Visual Computing Laboratory, Gjovik University: "CH Imaging @ The Norwegian Colour and Visual Computing Laboratory"
  • Hallvard Skjerping, NEO: HySpex
  • Francisco J. Burgos, University of Eastern Finland (on behalf of Markku Hauta-Kasari): "Spectral analysis of Finnish icons with spectral imaging techniques"

Sérgio Nascimento presenting the Colour Science Laboratory research activities.

Presentation of the Round Robin Test and the definition of its targets

  • Francisco J. Burgos, University of Eastern Finland (on behalf of Markku Hauta-Kasari, UEF): "X-Rite Color Checker® CLASSIC, first results from UEF and next steps"
  • Marcello Picollo, Applied Spectroscopy Lab., IFAC-CNR: "Painted test panel. Definition of the main scope of the preparation of the panel (or more than one); its structure / construction / stratigraphy / materials used and explanation of why they were selected"

Presentation of the COSCH Knowledge Representation

  • Frank Boochs, Mainz University of Applied Sciences: "Knowledge Representation (KR)"

Frank Boochs' presentation on "COSCH Knowledge Representation".

Results of the WG1 Taskforce Meeting in Braga

  • Presentations of the activities of the diverse groups by each participant.
  • Definition of STSM keywords: Calibration of imaging spectroscopic devices; Acquisition, elaboration, exporting, and storing imaging data-cubes; Multi-spectral and hyper-spectral imaging; Analysis and rendering of spectral image datasets; Accuracy and reproducibility of spectral imaging systems; Visualisation case studies (individual and joint)
  • Final output of WG1: Handbook on the best measurement procedures to be followed by users (people working in CH conservation field)
  • Knowledge Schema: Nomination of WG1 coordinator;
  • Collection of respective facts: First step focussed on definition of methodological / technical data on the imaging devices within WG1 teams (defined by F. Boochs as "realisation of an appropriate KR using state-of-the-art technologies");
  • Selection of typical scenario within WG1 (WG1 directly connected to WG4 activities);
  • Delivery of facts to COSCHKR operative team.

2014 - ICISP Special Session

At the International Conference on Image & Signal Processing (ICISP 2014), Cherbourg, Normandy (France), June 30 – July 2 2014, COSCH supported a special session on Digital Cultural Heritage, chaired by Alamin Mansouri and Frank Boochs, to which four oral and two poster presentations were selected. The oral presentations dealt with the application of multi- and hyper-spectral imaging techniques to the investigation of artworks and artists' materials mainly covering the COSCH WG1 activities. The session was well attended and several questions from the audience were addressed to the speakers. This testified the strong interest from scientists and researches with different cultural backgrounds in the application of multi- and hyper-spectral imaging systems, and their data elaboration, to the cultural heritage field. Furthermore, COSCH was well represented and the conference was a successful stage for promoting COSCH activities.

Oral presentations:

Sony George, Ana Maria Grecicosei, Erik Waaler, Jon Yngve Hardeberg:

Spectral Image Analysis and Visualisation of the Khirbet Queyafa Ostracon. (Abstract/presentation)

Lindsay MacDonald, Maria Filomena Guerra, Ruven Pillay, Mona Hess, Stephen Quirke, Stuart Robson, Ali Hosseininaveh Ahmadabadian:

Practice-based comparison of imaging methods for visualization of toolmarks on an Egyptian Scarab. (Abstract/presentation)

Tatiana Vitorino, Andrea Casini, Costanza Cucci, Maria João Melo, Marcello Picollo, Lorenzo Stefani:

Hyper-Spectral Acquisition on Historically Accurate Reconstructions of Red Organic Lakes. (Abstract/presentation)

Hilda Deborah, Sony George, Jon Yngve Hardeberg:

Pigment Mapping of The Scream (1893) Based on Hyperspectral Imaging. (Abstract/presentation)


Poster presentation:

Mihajlovic, V. Jelisavcic, B. Marinkovic, M. Todorovic, Z. Ognjanovic, S. Tomovic, V. Stojanovic, V. Milutinovic: "Serbia Forum Digital Cultural Heritage Portal".

WG1 - Autumn Meeting 2013

Find abstracts of WG 1 from Autumn Meeting below:

Timo Hyvärinen (Specim, Spectral Imaging Ltd., Oulu):

What makes push-broom hyperspectral imaging advantageous for art applications? (Abstract/presentation)

Members Members

Frank Boochs
Jaroslav Valach
Markku Hauta-Kasari
Ruven Pillay
Ferdinand Deger
Alamin Mansouri
Franck Marzani
Stefan Röhrs
Camille Simon
Andreas Sarakinos
Marcello Picollo
Jon Hardeberg
Hallvard Skjerping
Julio del Hoyo Melendez
Rui Bordalo
Sérgio Nascimento
Lidia Font
Santiago Royo
Francisco Miguel Martinez-Verdú
Edith Joseph
Bratislav P. Marinkovic
András Jung
Dirk Rieke-Zapp
Aurélie Tournié
Marvin Klein
Haida Liang
Daniel Vazquez
Sony George
Stefanie Wefers
David Strivay
Raju Shrestha
Rodica Mariana Ion
Nicole Bruhn
Eva Matouskova
Lindsay MacDonald
Michal Obarzanowski
Cristina Montagner
Francesca Piqué
Tatiana Mendes Vitorino
Giorgio Trumpy
Irina Mihaela Ciortan
João Manuel Maciel Linhares
Lazaros Grammatikopoulos
Harri Salo
Tiziana Lombardo
Christel Pesme
Zvi C. Koren
Aleksandar Mihajlovic
Hilda Deborah
Vera Moitinho de Almeida
Ana Gebejes
Aurélie Mounier
Keats Webb
Corinna Koch Dandolo
Manfred Schreiner
Wilfried Vetter
Przemyslaw Korytkowski
Agnieszka Olejnik-Krugly
Johan Linderholm