Tag Archives: university

Techniques for recovering lost texts

Research Fellow Renate Smithuis and Research Associate Stefania Silvestri, are working on a Catalogue of Codices, Scrolls, and Other Texts in Hebrew Script in The University of Manchester Library.

The Library holds one of the most important smaller collections of Hebrew manuscripts in Europe and this project will create a full, online catalogue compliant with current cataloguing and metadata standards. To support the production of the catalogue, digitisation of a number of manuscripts is being undertaken. All images, included fully digitised volumes, are added to the Hebraica Collection in the John Rylands Library Image Collections, LUNA.

A substantial portion of the Rylands Gaster manuscript collection have already been selected for digitisation, including a number of manuscripts that suffered water damage during the Second World War. The level of water damage varies, some texts are still legible but faint, others have whole sections of pages rendered illegible.

The Heritage Imaging Team have been investigating the best way to recover the text in these volumes, unsurprisingly, we have found that a single solution does not fit all. The aim of this blog post is to demonstrate the different processing options available to researchers. We are researcher-led in the work that we do with Multispectral Imaging of our collections, so if you come across a text you cannot read, please get in touch to discuss your needs in more detail (email: uml.chicc@manchester.ac.uk).

I should note at this point that these examples are not exhaustive and we are always in the process of developing new techniques.

Trials in image processing have been run on pages from Gaster Hebrew MS 1832. The first step of carrying out any specialist techniques is to produce a high resolution ‘standard’ light photographs. These are the images that you can access in high resolution in our online image collections. Often, close inspection at high resolution enables a reader to decipher more than they can read with the ‘naked eye’.

In this example, the first image shows page 1 recto of Gaster Hebrew MS 1832 in ‘standard’ light. You are able to see that there is some faded text on the page but it is extremely faded in some areas:

Gaster Hebrew MS 1832

Gaster Hebrew MS 1832 1 recto standard image

The second image shows a standard high resolution image which has undergone additional image processing in Photoshop. The image has been inverted to help the text show through in certain areas of the page.

Gaster Hebrew MS 1832

Gaster Hebrew MS 1832 1 recto standard image with processing

The third image shows page 1 recto again, a standard high resolution image which has undergone processing in Photoshop to bring out the most faded central areas of the text.

Gaster Hebrew MS 1832

Gaster Hebrew MS 1832 1 recto standard image with additional processing

Here is a detail from each file type for comparison:

The benefit of this approach is that these results can be achieved without any additional imaging of the manuscript and standard photo manipulation software can be used. In addition, once results have been achieved, these can be batch applied to a set of images for an entire manuscript. The results may not be 100% consistent depending upon the range of damage to each page, but if the results are ‘good enough’ it will save many hours of image processing time.


Our next example shows firstly, page 2 recto of Gaster Hebrew MS 1832 in ‘standard’ light, plus an example of the same image which has been processed in Photoshop:

However, with this example we took several further steps to recover the lost text. In this instance, the manuscript has also been imaged using Multispectral Imaging. We now use a Phase One Achromatic IQ260 digital back, iXr camera body and standard lens combined with Megavision LED lighting panels and a filter wheel to capture 17 images at different points along the electromagnetic spectrum. I have included 2 images here, take at 370nm (UV) with a long pass violet filter, and at 448nm (Deep blue) as these single images give the best results. In the infrared wavelength, the text on this manuscript disappeared completely, which suggests that it is an iron gall based ink.


Using multispectral imaging we are able to take our image processing and textual recovery even further. Using ImageJ software I have combined several of the individual wavelengths to create a ‘pseudocolour’ image. This applies false colours to areas of difference across the page. Note the two images below in colour.

The colour results are not attractive to every eye, especially to the colour blind so can be converted in to greyscale. In the examples here, I have added an additional filter using the Channel Mixer in Photoshop to increase the contrast of the text even further.

Here you can see details of all 8 examples described above, click on the image to flick through each detail.

There are obvious benefits of taking every possible step of image processing to recover as much text as possible. However, there are also drawbacks. The manuscript must be subjected to a second round of digitisation using the Multispectral Imaging system, this is not only time consuming, but for fragile items it also increases the possible risk of damage to the physical item. There is additional time required for the photographer to process the images and store the additional data. Metadata must be produced to accompany the new images and to detail the processing work that has been carried out on the images.

Finally depending upon the nature of the damage to the page, a reader may need to consult a combination of 2 or 3 final processed images in order to read the entire page. Additionally, there must be a flow of communication between the reader/researcher and the person processing the images in order to process the ‘best’ results.

Specialists are currently working on software solutions to allow us to present the data to readers which will allow the reader themselves to combine and ‘play’ with images to suit their needs. We will report on developments in this area when they are available. Until then, we will continue to take a ‘triage’ approach to image recovery, assessing each item against the needs of the researcher to take the right steps to uncover lost texts.


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Multispectral Imaging Trials with The Photon Science Institute – George Christian and Robert Longstaff



Measuring the wavelengths of the Megavision Panels using a spectrometer


We are all used to the fact that unique or very rare manuscripts, like those stored in the collections of the John Rylands Library, must be handled with extreme care. They are often only displayed to the public through a layer of protective glass or maybe even exclusively as photographic reproductions; the originals far too fragile to be brought out of the dark for extended periods of time.

Since they provide us with such a precious link to the past, it is very understandable that they should be treated in this way. So it might be easy to forget that this has not always been the case. There are many examples of manuscripts whose raw materials (usually parchment) were at one time deemed more valuable than the text they contained, and which therefore became palimpsests.

A palimpsest is a manuscript from which the text has been removed and replaced by new writing, effectively recycling the original material. This then creates a new challenge for scholars who wish to read the original text which may only be very faintly visible, if at all. Traditionally, the underlying text would have been read simply by close inspection of the faint impressions left by the writing. However, this is obviously limited to manuscripts for which this text is visible to the naked eye in the first place.

In the nineteenth and early twentieth centuries, scholars brought out the less visible text with various chemical cocktails which were often highly damaging to the manuscripts. More recently, far less invasive techniques have been developed based on a fundamental understanding of light and how it interacts with matter, and CHICC has teamed up with the Photon Science Institute (part of the School of Physics and Astronomy at the University of Manchester) to trial the technique of Multispectral Imaging.

We (George Christian and Robert Longstaff) are two fourth-year physics undergraduate students who are working with the imaging team to explore the potential usefulness of this technique. Multispectral imaging is the technique of capturing data (in this case photographs) from one source at multiple wavelengths of light. By treating these images as mathematical objects (where each pixel has a numerical value associated with it), they can be combined and manipulated in such ways as to produce images where the previously invisible text can be seen and interpreted (hopefully) much more easily. For example, often invisible text can be made very clearly visible by illuminating it with ultraviolet (UV) light. The trouble is, the text that replaced it is usually also just as visible in the image.

However, if an image taken at a wavelength where only the overlying text is visible is subtracted from the image where both texts are visible, then we are left with an image containing only the text that was previously very difficult or impossible to make out. The techniques we are using were employed on the now famous Archimedes Palimpsest, and the results they have achieved can be seen in full on their website (http://www.archimedespalimpsest.org/).

We have already had some success, although really we are learning as we go. Our main challenge is to find ways to bring out the “hidden” text as clearly as possible, and hopefully in a way that is useful to the scholars! This is a very exciting opportunity for us as it’s the first time this has been offered as a final-year project, and it offers a unique chance to work in the John Rylands Library which doesn’t happen very often for physics students!

George & Robert

George and Robert’s findings can be read here


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RTI Cuneiform tablets now online

Sumerian tablet P108057. From the Umma Period, 2100-2000 BC.

Sumerian tablet P108057. From the Umma Period, 2100-2000 BC.

Rylands Cuneiform tablets, digitised using Reflectance Transformation Imaging (RTI) are now available online. We posted an interesting piece a while back about the digitisation process here. The library worked in collaboration with the Cuneiform Digital Library Initiative based at UCLA, and Dr. Klaus Wagensonner of The University of Oxford. See the amazing images and transcriptions here.

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Digitising Latin MS 113

CHICC recently digitised a beautiful 15th century chronicle roll here at the Rylands.

We decided to make a quick video of us working, showing how we tackle imaging a 20ft parchment roll.

Have a look at the video below, the images can be found on LUNA here.

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Blackburn’s ‘Worthy Citizen’: The Philanthropic Legacy of R.E.Hart

A few weeks ago, CHICC traveled over to the Blackburn Museum to digitise some wonderful manuscripts from the R.E. Hart collection.

The work forms part of a much larger AHRC funded project for an exhibition of parts of the collection at the Senate House Library in London.

Hart 20966, f. 106v, Venetian Book of Hours, c. 1470-80

Hart 20966, f. 106v, Venetian Book of Hours, c. 1470-80

From the project blog:

“On the 1st of May, James Robinson, head photographer of the John Rylands Heritage Imaging group, worked on-site at the Blackburn Museum. The session had been arranged by our team member, Tony Harris, and the specifications for our display needs were agreed between James and Tony. The beauty of the John Rylands expertise, is that all the photography took place at  the Blackburn Museum itself. The manuscripts and incunabulae were therefore spared transportation, and our project was spared that expense. Jamie managed to take sixty photographs over the course of the day, assisted by Vinai Solanki, the curator of the Museum , and myself. The kit which Jamie had with him enabled us to photograph items of great variety in size and shape, from a palm -sized English Book of Hours, to a fold-out fifteenth-century map of Jerusalem that extended to five feet in length. The images will be used on a display screen at the exhibition, to enable the viewers to see more of the manuscripts themselves, and to illustrate our catalogue for the show. Vinai will also use the images to raise the profile of the Hart Collection in the community itself.”

Be sure to follow the blog for progress on the project, and look out for the exhibition opening in November.

Image courtesy of Blackburn Museum

Image courtesy of Blackburn Museum

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CHICC Digitising the Archive of John Henry Cardinal Newman



CHICC are pleased to announce we have begun the digitisation of John Henry Cardinal Newman’s vast archive. The project is a collaboration between ourselves, The National Institute for Newman Studies, in Pittsburgh and Birmingham Oratory where the archive is kept.

A new blog is now live, following the progress of the digitisation project make sure to follow for regular updates!

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St Christopher Woodcut undergoes the National Gallery’s Infrared Imaging


St. Christopher Woodcut being imaged using Osiris camera

    On Tuesday 15th January 2013 the Rylands were very pleased to welcome Rachel Billinge, from the National Gallery, and Ed Potten, Head of Rare Books at the University of Cambridge for some very exciting imaging.

Rachel brought with her an Osiris camera for high-resolution infrared reflectography. The camera was developed by Opus Instruments based on a prototype that was designed and built by the National Gallery‘s Science and Conservation departments. The Osiris camera records infrared light wavelengths from 900-1700 nanometres, reaching further in to the infrared light spectrum than a standard CCD sensor could. The camera takes many images of an item and automatically stiches each ’tile’ together, saving hours of post-processing time.


St. Christopher Woodcut being imaged using Osiris camera


View of Osiris capture as it happens, the camera automatically stitched together each ’tile’ to create a full high-resolution image of the page


Rachel Billinge from the National Gallery working on a capture of the St. Christopher Woodcut using an Osiris camera

Rachel produced images of the St. Christopher Woodcut, in a bid to produce a legible image of the watermark to confirm, or otherwise, the dating of the Woodcut. The St Christopher woodcut, 1423, is the earliest dated example of European printing. It is preserved as an endpaper in a manuscript dated 1417 from Bohemia, the ‘Laus Virginis’. Rachel also imaged the Annunciation Woodcut, although no watermark is believed to be present in this print.

Members of staff from across the Library were on hand to support and analyse the images as they were produced. We await the results with bated breath… we will share the findings with you in a follow up post as soon as we possibly can.


Analysing the results… watch this space!

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Spectral Imaging @CHICC

CLICK for animated gif showing the sequence of the light panels across the spectrum. from UV, through visible to infrared.

Recently at CHICC we have finally begun our tests with our new MegaVision spectral lighting panels. Micheal Toth who has worked on the spectral imaging of the Archimedes palimpsest and other cultural imaging projects joined us for a 2 day workshop. Michael also gave a great presentation to staff about his recent work on the Galen Palimpsest digitisation project, and the importance of creating an online repository for the data. Michael has also been working on an incredible spectral project within St Catherine’s Monastery in the Sinai desert, a wonderful in depth article can be found here.

The light panels work through the electromagnetic spectrum, emitting light from 12 different wavelengths, starting off in UV and working through visible into infrared. We removed the IR filter from our Phase One P45+ back to be able to pick up the invisible light. By photographing objects under this lighting system, we are able to see what is essentially hidden, either text under text, water marks, text on pasted down pages and text obscured by damage.

The 12 wavelengths captured; 365nm UV, 455nm Royal Blue, 470nm, Long Blue, 505nm Cyan,535nm Green, 570nm Amber, 625nm Red700nm IR,735nm IR, 780nm IR, 870nm IR, 940nm IR. This is a Coptic palimpsest fragment, which also has burn damage. Even without processing with ImageJ, we are getting visible results.

The 12 images captured  are then processed through open source software ImageJ. This is the more difficult part of the process. The software is incredibly powerful, but it takes time to process the images and create results. We are currently working with image scientist Bill Christens-Barry in the US who will guide us through imageJ, and work on the images we have collected so far.

We tested the system on a variety of different objects from our collections, to test how the lights can help us with different problems. The famous St. Christopher woodcut, to try and bring out the watermark on the pasted down page. The above Coptic Palimpsest fragment, inscriptions in the Gutenberg Bible that have faded, and most effective without processing, carbonised Greek papyrus fragments, that are barely legible, completely when photographed under normal conditions. The below image shows the difference between normal and infrared. Even without processing the images through ImageJ, you can see the text is now clear.

Carbonised Greek Fragment 222 folio 2.

We will be sending our captured images over to Bill who will guide us through the processing. We will have some more conclusive results soon.

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New Rylands Special Collections Blog is now Live….

A brand new blog for the John Rylands Special Collections is now live. Expect some great insights into some of the incredible items from the collections. Don’t forget to follow the blog for regular updates.

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Japan, Described and Illustrated by the Japanese. Out Now!

Before Christmas, we were working again very closely with The Folio Society, to create a facsimile of the fabulous 10 volume copy of  Japan, Described and Illustrated by the Japanese we have in our collections. See this past post. Well, we are delighted to announce that the Folio Society edition is now available for pre-order!

One of the most opulent pictorial books ever published, Japan captures a vanished world in 259 hand-coloured photographs. Now, for the first time, this landmark work is reproduced in its entirety in two luxurious volumes

If it’s anything like our previous collaboration on Sharpe’s Birds of Paradise, it is guaranteed to be something special.

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