Launch pixel+ viewer: New dimensions take a deeper look at heritage

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Together with the Art & History Museum and the Royal Library of Belgium (KBR), KU Leuven is launching an online open access application to view heritage objects dynamically and interactively online. This pixel+ viewer allows you to view centuries-old objects in a different light and reveal hidden details.  

Japanese print on paper (© KU Leuven Libraries collections) in the pixel+ viewer

As a result of the Corona crisis, museums and other heritage institutions today have little or no physical access, both in Belgium and abroad. It puts the consultation of objects and the study of our past under strong pressure. In part, we can fall back on digitised objects, notes and old publications, but these only represent part of the information, which means that important details can be overlooked. Fortunately, the sector, in collaboration with engineers, has devised solutions to remedy this.

In the heritage sector, the digitisation of objects has long been the focus of attention and experimentation. For the public, this usually results in an online photo that can be zoomed in or on which the contrast can be adjusted. These are purely colour images, standard digital photographs conceal no extra information. However, different types of image scanners register a lot more characteristics of a surface than just the colour. Being able to visualize this information in a handy online tool therefore offers new possibilities for anyone working with heritage objects. Think, for example, of the KBR drawings by Pieter Bruegel the Elder that were recently examined by KU Leuven. The researchers were able to study the paper down to the fibre using their Portable Light Dome (PLD) scanner. They also got a much better view of the extensive range of techniques used by the old master.

Detail on original Pieter Bruegel the Old drawing from 1557 (KBR: II132816, Luxuria), without colour the imprinted stylus traces of the engraver become visible (© Fingerprint, KBR and KU Leuven).

Software is the key

Over the past 15 years, KU Leuven researchers, together with various partners from the heritage sector, have developed digital techniques that can visualise objects to an unprecedented level of detail: the PLD scanner. “With this method, they illuminate an object from a large number of angles and take photos of it, the so-called ‘single-camera, multi-light recording’, says Hendrik Hameeuw, co-coordinator of the project at KU Leuven. “The way in which this recording is subsequently processed determines which characteristics of the surface, such as relief or texture, the software can show and thus how the user experiences the object”.

New universal file format

 “To be entirely complete, we actually have to look at the file types of these interactive datasets,” says Hameeuw. Most heritage institutions calculate and store these types of images of their heritage with a specific image format, usually RTI/HSH. The software developed in Leuven works with PLD files (ZUN, CUN) that have extra functionalities compared to those RTI/HSH files. Pixel+ now makes this way of calculation available to the whole world, not only by offering it online, but also by introducing a new kind of container file for it: glTF. “Compare it with an ordinary photo on your computer. It will probably be a JPEG or GIF file. But if you want to work with it in Photoshop, the program will turn the same image into a PSD file”. These glTFs are compatible with both the Leuven PLD and the RTI/HSH files. “With this we offer a new universal standard for this kind of images and we also open them immediately via the online pixel+ viewer, a kind of free photoshop for ‘single-camera, multi-light recording’ images”. This allows both RTI/HSH and PLD files to be studied and compared within the same program for the first time.

A new world

Pixel+ extracts a lot of extra information from the available data. The objects, such as old coins, miniatures or paintings, suddenly acquire extra dimensions after hundreds of years, which can be used for research on these objects to gain new insights. Especially in the field of 3D (geometry) and the correct understanding of the reflections of light on an object, the Leuven software is taking major steps forward.

“The technology is interesting for many objects, from clay tablets over coins to paintings or medieval manuscripts,” explains Hameeuw. “The software allows, among other things, the objects to be viewed virtually with different incidence of light, the relief to be mapped at pixel level or a 3D visualisation to be generated”. Frédéric Lemmers of the KBR Digitisation Department joins in: “By even combining it with multi-spectral imaging, researchers recently discovered that the heads of some figures in KBR’s 13th-century Rijmbijbel were painted over at a later date.” At the Art & History Museum, the technology was used to make heavily weathered texts on almost 4,000-year-old Egyptian figurines readable again.

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Same detail of illumination on folio 106 (verso) in the Rijmbijbel of Jacob van Maerlant (MS15001, ca. 1225-1291) with varying visualizations of multi-spectral PLD dataset, note the red lines around the heads (= later additions) (© KBR and KU Leuven).

Institutions from all over the world, from the Metropolitan Museum of Art in New York (USA) to the Regionaal Archeologisch Museum a/d Schelde in Avelgem (Belgium), will be able to upload, consult and study their own datasets or files in pixel+. The software converts the information according to various new standards and allows users to access the virtual heritage objects interactively. “This development really is a milestone for the heritage sector”, emphasises Chris Vastenhoud, promoter of the project from the Art & History Museum. “A whole new world will open up for heritage institutions worldwide. They will be able to document and share a lot of additional information in order to communicate about the objects in their collections”.

Pixel+ is available to everyone at http://www.heritage-visualisation.org with examples of objects from the collections of the Art & History Museum, KBR and KU Leuven.

The online pixel+ viewer with an example of a cuneiform tablet from the collection of the Museum Art & History, Brussels. (© Art & History Museum and KU Leuven).

The project is a collaboration between Art & History Museum, KU Leuven Department of Electrical Engineering, KU Leuven Illuminare, KU Leuven Libraries Digitisation and KBR; and was funded by the Federal Science Policy Office (BELSPO) through the BRAIN-be programme (Pioneer projects).

At the beginning of April 2020, the pixel+ project staff already presented their results during the online (as a result of Corona) SPIE conference. As a result, the paper below was published: 

Vincent Vanweddingen, Hendrik Hameeuw, Bruno Vandermeulen, Chris Vastenhoud, Lieve Watteeuw, Frédéric Lemmers, Athena Van der Perre, Paul Konijn, Luc Van Gool, Marc Proesmans 2020: Pixel+: integrating and standardizing of various interactive pixel-based imagery, in: Peter Schelkens, Tomasz Kozacki (eds.) Optics, Photonics and Digital Technologies for Imaging Applications VI, Proc. of SPIE Vol. 11353, 113530G. (DOI: 10.1117/12.2555685)

read paper – see presentation

Additional examples can be viewed and created at http://www.heritage-visualisation.org/examples.html

 

 

 

 

New paper and poster presented at the Archiving 2018 conference

At the Archiving 2018 conference (April 18-20, NARA, Washington, IS&T) a new paper and poster was presented: Bridging Multi-light & Multi-Spectral images to study, preserve and disseminate archival documents.

Bruno Vandermeulen, Hendrik Hameeuw, Lieve Watteeuw, Luc Van Gool, Marc Proesmans, Bridging Multi-light & Multi-Spectral images to study, preserve and disseminate archival documents, Society for Imaging Science and Technology, Archiving2018: Final Program and Proceedings pages:64-69

 

Discover RICH

Microdome imaging workshop at the J.P. Getty Museum

Between January 27th and February 3th the RICH team has been working together with the scientists and conservators of the J.P. Getty Museum and Research Institute in Los Angeles. Various artifacts of the Museum collection have been monitored and studied with Photometric Stereo such as medieval manuscripts, master drawings, bookbindings and daguerreotypes.

A daguerreotype by Jacob Byerly (1807-1883); left full image made with the White Light Microdome; middle a detail with raking light; right same detail with shaded filter showing degradation. Click on the image to enlarge;  collection J. P. Getty Museum

Both White Light and Multi-Spectral Microdomes have been used. The RICH Project, the technical background and the research targets have been highlighted the on February 2nd during the lecture: Microdomes and Manuscripts: Multi-Spectral and Photometric Stereo Imaging for Illuminations, Drawings and Documentary Heritage. After the lecture, a hands-on workshop was given at the Imaging Studio of the Getty Center.

Mira Calligraphiae Monumenta (Georg Bocskay & Joris Hoefnaegel, 1561-62), folio 33; image with White Light Microdome, collection Getty Museum

Mira Calligraphiae Monumenta (Georg Bosky & Joris Hoefnaegel, 1561-62),  detail, folio 33; Multi-Spectral Microdome; top left shaded filter; top middle Infrared light (850 nm); top right Red light (623 nm); below left Green light (523 nm); below middle Blue light (460 nm), below right UV light (365 nm)

Imaging embroidered bookbindings at the Special Collections of the University of Amsterdam

In preparation of workshop on Historical Embroidered Bookbindings at the Special Collections of the University of Amsterdam this summer, the RICH team monitored 15 precious historic bookbindings (16^th – 19^th century) with delicate needlework on velvet, silk and satin last week. The imaging was done with the white led microdome and with the multispectral microdome. Weaving, stitching and embroidering techniques were revealed in great detail, taking the researchers view through the eye of the needle.

Results will be presented during the 3-Days Seminar on Embroidered Bindings, Wednesday 19 – Friday 21 August, Summer School History of the Book at the Special Collections of the University of Amsterdam, Oude Turfmarkt 129, 17-28 August 2015. See: http://bijzonderecollecties.uva.nl/en/what-s-on/events/content/events/2014/08/summer-school-history-of-the-book.html

The RICH-project featured in the new LIBISzine magazine

The RICH-project is featured in the new LIBISzine magazine. Apart from the cover, you will find an interview with Lieve Wateeuw on the project.

Newest acquisition of the KU Leuven University Library monitored with the Multispectral Microdome

KU Leuven, MS1993, folio 008R with normal and IR light; folio 045R with visual and false color IR

In May 2015 the KU Leuven University Library acquired a unique illuminated manuscript from the Celestine monastery of Arenberg (Leuven, Belgium). The title “Preparationes ante missam” (“Preparations for the mass ‘) was written and illuminated in 1582 in the Celestine monastery in Heverlee, Leuven by the later prior Petrus Angeli. The manuscript is remarkably small in size (100 x 65 mm), and has 34 illuminations. At the beginning of the book Angeli painted eight heraldic weapons, held by female figures, angels, soldiers or ‘wildemannen ‘, followed with sixteen full-page miniatures. They are meticulously painted in warm and brilliant colors and finished with shell gold, depicting scenes of the Old and New Testament. The dedication miniature on folio 45 refers to the Croy’s family, members of the Knights of the Golden Fleece.

Last week the manuscript was examined in the Imaging Lab of the University Library with the new Multispectral Microdome developed in the framework of the RICH project. First conclusions are that the ‘cartouches’ and the coat of arms in the manuscript remained blank and were never overpainted. Moreover, the results showed with IR light that there was no underdrawing made with a carbon based medium, but probably some outline drawing of very small individual figures by a transfer technique. The false color imaging of folio 045r revealed a complex mixed color palette, characteristic for the late 16^th century illumination technique. The coming academic year, the newly arrived manuscript will be examined and analyzed to reveal it’s hidden features.

Workshop on multispectral imaging

The past days (May 11-13) the RICH team organized a workshop on multispectral imaging at the Imaging Lab of the University Library KU Leuven, which coincides with the implementation of the Multispectral Microdome. Mike Toth, Bill Christens-Barry and Alberto Campagnolo set up their imaging system for multispectral capture developed during the Archimedes Palimpsest project. Eric Joakim of Phase One kindly provided an IQ260 Achromatic digital back and IXR camera for capture.

Mike Toth, Lieve Watteeuw, Alberto Campagnolo, Bruno Vandermeulen, Bill Christens-Barry and Eric Joakim, photo Mike Toth

Western and eastern paper, parchment and papyrus documents and archaeological objects such as Egyptian execration statuettes were monitored. These objects were captured through 16 different spectral bands, ranging from UV to IR. We were specifically looking at censored, deleted and faded texts, pictorial layers and false color visualisation of polychrome layers of medieval illuminations.

The Timbuktu manuscripts, which are being researched and digitized at the moment at the Imaging Lab, were also the focus of attention.

Preparing Egyptian Execration Statuettes for capture

Focussing before multispectral capture

Lieve Watteeuw, Mike Toth, Bill Christens-Barry, Alberto Campagnolo and Eric Joakim at work in the Imaging Lab of the University Library

Lieve Watteeuw, Mike Toth, Alberto Campagnolo and Athena Van der Perre looking at a manuscript.

RICH presents the new Multispectral Microdome

Today the RICH team presented the first preliminary results of a Microdome with multispectral RTI capability at the Digital Humanities Spring Session (KU Leuven, April 28-29).

The new Multispectral Microdome is equipped with 228 different LED lamps. Five different spectra are evenly distributed over the dome: UV at 365 nm, Blue at 460 nm, Red at 523 nm, Green at 623 nm and IR at 850 nm. A black and white sensor of 28 Mp with extended sensitivity in UV and IR is mounted on top of the dome. After first analysis, the software will be fine-tuned and further enhanced.

Manuscript: KU Leuven, Tabularium, MS 1007, folio 41V

Imaging the topography of illuminations and bookbindings

Poster presented at ICOM-CC’s 17th Triennial Conference, Melbourne, September 15-19

You can view the poster in a larger version here.