Advanced Imaging Services at KU Leuven Libraries Webinar slides
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The document outlines the advanced imaging services at KU Leuven Libraries, focusing on digitization and multi-spectral imaging technologies that enhance the visualization of heritage objects. It details the techniques, equipment, and procedures employed in imaging projects, while also highlighting collaborations and the incorporation of imaging into library services. Furthermore, it addresses the benefits of these services for research and conservation, alongside the challenges and future developments in the field.
Advanced Imaging Services at KU Leuven Libraries Webinar slides
- 1. Advanced Imaging Services at KU Leuven Libraries Bruno Vandermeulen Hendrik Hameeuw @imagingkuleuven
- 2. Content & Scoop • Digitisation and Imaging at KU Leuven Libraries • Standard Multi-Spectral Imaging • Multi-Light Reflectance Imaging o White Light Portable Light Dome o Multispectral Portable Light Dome what is the technology roadmap to successful results examples of projects & results incorporation library services 2
- 3. Digitisation and Imaging at KU Leuven Libraries 3 KU Leuven Libraries Library ServicesLIBISSpecial CollectionsArtes2Bergen Policy Unit Administration, Finance, HR, Communication SBIB GBIB FBIB PBIB RBIB EBIB Faculty libraries Digitisation & Document Delivery Document Delivery (ILL & scan on demand) Research & Policy Development Document Processing Policy Support & Advise Digitisation Imaging Lab
- 4. Digitisation and Imaging at KU Leuven Libraries • Digitisation and Document Delivery Department • Focus on projectmanagement (in house and outsourced digitisation projects) • Imaging Lab • Focus on quality • Respect for the materiality of objects (adapted infrastructure) • Consistent (high) quality level based on international standards • Close collaboration with research (such as Book Heritage Lab) • Implementing techniques to advance research • Development and implementation of new tools • Not limited to KU Leuven collections 4
- 6. Technology 6 • Beyond the visible light/spectrum Based on photography Outside the “comfort” zone of standard practice Extra (expensive) equipment • New possibilities for visualisation of features not visible to the human eye More complex capture procedures Slower imaging More complex storage issues Extra research & dissemination strategies Effect of MS imaging on canvas paintings The electromagnetic spectrum
- 7. Technology: Camera 7 Standard filtering, blocking of visible light towards a RGB pattern (Source: http://eladorbach.blogspot.com) Removal of UVIR and AA filters (Source: https://blog.mingthein.com) • Normal camera: • 400-700 nm • Modified (UV and IR sensitive) • 310-1100 nm • 310-400: UV • 400-700: VIS (white light) • 700-1100: IR • (Without Bayer-filter) Converted DSLR camera we selected
- 8. Technology: Lens 8 • Technical limits of standard lenses Hotspots (internal reflections) Shift in plane of focus Chromatic aberration in standard lenses causes different wavelengths of light to have differing focal lengths (Source: Lens6a.png, Creative Commons Attribution-Share Alike 3.0 Unported license.)
- 9. Technology: Lens 9 • CoastalOpt 60 mm UV-VIS-NIR • Full Apochromatic range 315 nm - 1100 nm • Fluorite glass elements
- 10. Technology: Light sources 10 • 2 options: Emitted light is broad spectrum Emitted light in narrow spectrum (narrow) band pass filters need to be used to filter the emitted and reflected light Very accurate, but expensive and less flexible white light + IR light source IR band pass reflection 1 2 narrow band emitter: blue reflection
- 11. Technology: Light sources 11 • 2 options: Emitted light is broad spectrum Emitted light in narrow spectrum (narrow) band pass filters need to be used to filter the emitted and reflected light Very accurate, but expensive and less flexible white light + IR light source IR band pass reflection 1 2 narrow band emitter: blue reflection UV emitter or
- 12. Technology: Calibration 12 • Conventional Technical Photography (TP) Established imaging standards (Metamorfoze, FADGI, …) Based on widely adopted commercial calibration cards and color targets (X-Rite Colorchecker SG, …) • Multispectral Imaging (MSI) UV target Diffuse Reflectance Standards (i.e. Spectralon) Pigment chart
- 13. Technology: processing • Image stack • False color images • Enhancement processing • Advanced processing routines (PCA, spectral unbinding, …) • to visualize features hardly or not visible to human eye 13 KU Leuven, Tabularium MS 1073
- 14. Standard Multispectral Imaging Roadmap KU Leuven 14
- 15. First trials with inadequate equipment 15 • Nikon D100 (limited sensitivity in IR region), 2008 • Standard VIS lens • Tungsten light • Cheap online acquired IR filter
- 16. First trials with inadequate equipment 16 • Phase One Achromatic Back (2011) • Standard 80 mm VIS lens • Cheap online acquired IR filter • UV: blacklight Color IR UV KU Leuven, Tabularium MS 1007, 042V Color IR UV KU Leuven, Tabularium MS 1014, 038V
- 17. Equipment: Filters 17 • Filters 1 Cheap online acquired filters • Filter kit 2 Forensic Photo kit: Peca • Additional filters 10 nm Bandpass filters
- 18. A first assignment 18 • Antifonarium illuminations • Simple procedure • Immediate results o Underdrawings o Surface characteristics VIS IR 850 nm UV 365 nm Private collection, Antifonarium, f 015R, detail 01 VIS IR 850 nm UV 365 nm Private collection, Antifonarium, f 015R, detail 02
- 19. Equipment: Light sources 19 • White light + IR emitter: standard studio flashes or tungsten light (halogen) • UV emitter: UV tube 365 nm and Black Light
- 20. First funded projects 20 • Development of Multispectral Portable Light Dome (RICH-project 2012) see infra • Establishing simple, standardized recording & processing pipeline for multispectral imaging of fragile Ancient Egyptian figurines (EES- project 2014) Full spectrum converted NIKON D610 DSLR camera Apochromatic lens Forensic Photo Kit: Peca filters TechSpec Hard Coated 10 nm bandpass filters (356, 730, 780, 850, 930 nm) Calibration in VIS, manual/visual adjustments in UV and IR
- 22. EES-project 22 • Limited number recordings • Simple post-processing o Photoshop color-channels o Enhancement processing False Color-IR B-channel LAB based on False Color- IR VIS RMAH-MRAH: E.7460
- 23. New filters & New calibration 23 • MidOpt filters oNarrow bandpass filters o Across/Overlap entire spectrum: c. 320nm – 950nm o For stability equipped with magnetic filter rings lens magnetic holder magnetic filter ring filter attached attached Selection of bandpass filters represented across electromagnetic spectrum (Source: Curve Compare sheets MidOpt)
- 24. Technology: Filters 24 • Filter kit 3 Selection of MidOpt filters 324nm Near-UV 405nm Violet 440 nm Violet 505nm Cyan 590nm Orange 635nm Light Red 400-700nm VIS 660nm Dark Red 695nm Red/IR 725nm NIR 780nm NIR 830nm NIR 880nm NIR 940nm NIR
- 25. New filters & New calibration 25 • Calibration MSI calibration card by Cultural Heritage Science Open Source Object-Level Target with Munsel patches by Image Science Associates Multi-step target with spectralon by Labsphere
- 26. 26 New filters & New calibration • Calibration via reflectance values monitoring (color readout) in Capture One (L.A.B.) oIR goes down on Munsel patches o UV much to low on MSI calibration card and Munsel patches oOnly spectralon stays consistent
- 27. New filters & New calibration 27 • Calibration with spectralon o Rough tuning during capture Aperture Shutter speed ISO o Fine tuning in post- processing Exposure Source: Labsphere Spectralon Standards Datasheet
- 28. Limits of standard Multi-Spectral Imaging 28 • Time consuming easily min per sequence • Stability throughout the recording sequence • Post-processing fine-tuning reflectance • Dark room for all-including capture • Price all basic equipment together: ±12870 € - Camera (D610) + Conversion: 1900,- - Lens (CoastalOpt UV-VIS-IR): 5500,- - MS Filter set + magnetic rings: 4500,- - Software (Capture One): 300,- - Calibration (spectralon): 670,-
- 29. Benefits of standard Multi-Spectral Imaging 29 • Allow standard MSI output conservation, underdrawings, materiality, … • Relative simple procedure doable for a normal institute photo-lab • Standard service incorporable in service catalog • Extra services towards research and conservation • Price Investment can be spread over time
- 30. An example of extra service 30 • Identification of materials 1. Capture of reference material Spectralon reference Historical Pigment Checker (v.5) by Cultural Heritage Science Open Source
- 31. An example of extra service 31 • Identification of materials 1. Capture of reference material 2. Capture of heritage object same settings Spectralon reference KU Leuven - Ms.1333
- 32. An example of extra service 32 • Identification of materials 1. Capture of reference material 2. Capture of heritage object 3. Make spectral curves oImageJ (Open Source) o Spectral fingerprint of pigment o Conversion in spreadsheet of reflectance values method as proposed on Archiving 2018, Washington by Fenella France & Meghan Wilson, Library of Congress Screenshot of establishing MS reflectance curves in ImageJ workspace
- 33. An example of extra service 33 • Identification of materials 1. Capture of reference material 2. Capture of heritage object 3. Make spectral curves 4. Compare For this example a positive identification of ‘azurite’ The MS reflectance curve as plotted in Excel for the blue pigment on Ms. 1333 of KU Leuven Libraries The MS reflectance curve as plotted in Excel for the azurite pigment patch Pigment Checker (v.5) by Cultural Heritage Science Open Source
- 34. (near) Future • 3Pi: Papyrus Parchment Paper Imaging • (Book Heritage Lab (FTRS), Illuminare, ESAT, KU Leuven Libraries) • Integration of both visualization and analytical tools (tools for data creation) • Processing • Dissemination 34
- 35. Multi-light Reflectance Imaging White Light Portable Light Dome Multispectral Portable Light Dome Technology & Roadmap 35
- 36. The system 36 OUTPUT Relightable Images/Pixels Enhanced visualization shaders Genuine 3D BRDF analyses 1980 Theoretic principles of photometric stereo 1999 Malzbender’s dome @ HP 2003 Start of PLD project @ KU Leuven 2005 PLD for cuneiform studies 2011 PLD for documentary heritage 2014 Multispectral PLD • Multi-light Reflectance Imaging (MLRI) • Based on principles of Photometric Stereo (PS) • Related with RTI
- 37. Acquisition devices 37 • The Portable Light Domes - WL Microdome - WL Minidome (version 1 & 2) - MS Microdome - MS Minidome Microdome Minidome (Version 1) Minidome (Version 2) MS Microdome Minidome (Version 1)
- 38. Acquisition devices 38 • LEDs • Ultraviolet (UV): 365 nm • Blue: 460 nm • Green: 523 nm • Red: 623 nm • Infrared (IR): 850 nm FINGERPRINT project (Imaging Bruegel Graphic Work) ARTGARDEN project (Imaging Closed Gardens) EES project (Imaging Ancient Egyptian Figurines)
- 39. Standard output 39 Multispectral Imaging of an Egyptian Mummy Portrait Viewer interface with cuneiform tablet ↙ Compilation of multispectral images (IR, R, G, B, UV, false color PCA’s) → Standard visualisations in the desktop viewer, white light dataset ↘
- 40. Principles in brief 40 Viewer interface with cuneiform tablet Final Compressed Data File (.cun or .zun) Greek silver coin – Leuven Art collection (o.i. 522) Greek silver coin – Leuven Art collection (o.i. 522) 3D models per side Photometric Stereo x228 or x260
- 41. From white light to multispectral 41 Viewer interface with cuneiform tablet
- 42. From white light to multispectral: Case 1 42 Visualization and measuring of the topography: Leuven, Mauris Sabbe Library – leather book binding • White Light PLD Visualisation Color shader with perpendicular light
- 43. From white light to multispectral: Case 1 43 Visualization and measuring of the topography: Leuven, Mauris Sabbe Library – leather book binding Color shader with raking light • White Light PLD Visualisation
- 44. From white light to multispectral: Case 1 44 Visualization and measuring of the topography: Leuven, Mauris Sabbe Library – leather book binding Color shader with raking light & measure tool • White Light PLD Visualisation
- 45. From white light to multispectral: Case 1 45 Visualization and measuring of the topography: Leuven, Mauris Sabbe Library – leather book binding Shaded shader with raking light • White Light PLD Visualisation
- 46. From white light to multispectral: Case 1 46 Visualization and measuring of the topography: Leuven, Mauris Sabbe Library – leather book binding Shaded shader with raking light • White Light PLD Visualisation
- 47. From white light to multispectral: Case 1 47 Visualization and measuring of the topography: Leuven, Mauris Sabbe Library – leather book binding Sketch1 shader • White Light PLD Visualisation
- 48. From white light to multispectral: Case 2 48 Conservation – monitoring surface conditions before and after (Private Collection – Illuminated Manuscript, Antiphonary, folio 4r) untreated treated Color shader with normal relighting • White Light PLD Physical analysis
- 49. From white light to multispectral: Case 2 49 untreated treated Color shader with raking light • White Light PLD Physical analysis Conservation – monitoring surface conditions before and after (Private Collection – Illuminated Manuscript, Antiphonary, folio 4r)
- 50. From white light to multispectral: Case 2 50 untreated treated Shaded shader with raking light • White Light PLD Physical analysis Conservation – monitoring surface conditions before and after (Private Collection – Illuminated Manuscript, Antiphonary, folio 4r)
- 51. From white light to multispectral: Case 2 51 untreated treated Color shader with measure tool • White Light PLD Physical analysis Conservation – monitoring surface conditions before and after (Private Collection – Illuminated Manuscript, Antiphonary, folio 4r)
- 52. From white light to multispectral: Case 2 52 untreated treated -5 -4 -3 -2 -1 0 1 0 10 20 30 40 50 60 70 80 90 Folio 34R Folio 34R Treated • White Light PLD Physical analysis Conservation – monitoring surface conditions before and after (Private Collection – Illuminated Manuscript, Antiphonary, folio 4r)
- 53. From white light to multispectral: Case 3 53 MS PLD reflection maps of the Pigments Checker (CHSOS); Above: ultramarine; Below: azurite Reflection maps and histogram. Above: pixel and zone X ultramarine; Below: pixel and zone Y, azurite Detail in Bible of Anjou (f001v): Pigment analyses - both azurite and ultramarine appear as blue (C = false color: IR/G/B) Analysing the reflections in 5 spectral bands • Multispectral PLD Spectral analysis
- 54. From white light to multispectral: Case 4 54 • Multispectral PLD Combined analysis (physical & spectral) Detail on NHD27 ‘Luxuria’ by Bruegel (drawing SII132816 & print SII22656, both KBR, Brussels)
- 55. From white light to multispectral: Case 4 55 Detail on NHD49 ‘View of Tivoli’ by Bruegel (print SI9412, KBR, Brussels) Legend A: Standard Phase One image B: Backlight Phase One image C: Multispectral PLD, normal RGB representation D: UV representation with MS PLD E: Shaded shader of MS PLD viewer F: False color Red-Green-UV • Multispectral PLD Combined analysis (physical & spectral)
- 56. Library Services and Advanced Imaging 56
- 57. Service integration 57 Preparation • Project application • Agreement • Book loans • Transport • Pre-/conservation Metadating Collection / Items • Analysis existing metadata • Creating (extra) metadata • Creating metadata for digitisation (‘digi numbers’) Standard digitisation • Imaging • Checks and processing • Upload Enrichment • OCR • High resolution viewer • Advanced imaging • … Ingest and publishing • Metadata – image matching • Ingest • Checks Post-care • Archiving documentation • Image preservation Advanced imaging Data work environment Data delivery
- 58. Added value 58 • Integrated service: standard digitisation and imaging • Embedding advanced imaging on institutional level • At the service of researchers, in close collaboration • Build up of high-end non-standard infrastructure through external funding • Pooling of equipment, resources and expertise • Library = lab to test out routines, develop workflows, … • High(er) visibility
- 59. Thank you! 59 Contact: Bruno Vandermeulen: bruno.vandermeulen@kuleuven.be Hendrik Hameeuw: hendrik.hameeuw@kuleuven.be @imagingkuleuven https://bib.kuleuven.be/english/research https://enrichingheritage.wordpress.com Projects involved: https://portablelightdome.wordpress.com https://fingerprintbruegel.wordpress.com
Editor's Notes
- #4: Digitisation: project management; imaging; copyrights and property rights (also: research on imaging techniques; policy preparation) Partnerships within the library for MD (collection curators or metadata department) and for CMS & archiving (LIBIS)