Hearing Voices from a Broken Disc

Hearing the voices of people who lived in another century brings them close to us, but early recording technology makes hearing them a challenge. In the first half of the 20th century a common recording method was to use discs with a lacquer surface. Sound waves caused a stylus to vibrate and cut grooves into the lacquer while the disc turned. The recording was played back by running another stylus through the grooves and amplifying the sound. The inner core of the discs was metal, cardboard, or even glass. Playing these old recordings is a problem – the lacquer deteriorates over time, developing cracks and sometimes detaching from the core, and of course glass is easily broken.

Until a few years ago, a broken record was a lost cause – while conservators can repair many types of damage, they cannot put broken glass recordings back together again. But in 2013 scientists from Lawrence Berkeley National Laboratory developed IRENE (Image Reconstruction Eliminate Noise, Etc.), a digital imaging system that can make a picture of the grooves on a disc and then transform the images into digital sound files. Carl Haber, the lead scientist and a Columbia graduate, won the MacArthur Fellows award for his work. (For more on Haber and how he developed IRENE, see this article in Columbia College Today).

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Glass disc, WNEW Join the News Reel, 10 February 1944, American Bureau for Medical Aid to China 1937-2005, Rare Book & Manuscript Library, Columbia University

Like many other libraries and archives, Columbia has its share of glass and other fragile recordings. When IRENE became available from the Northeast Document Conservation Center, we sent off this disc from 1944 to test the new service. The disc had shattered and small fragments along the edges of the breaks had been completely lost. Using IRENE, each surviving fragment was separately imaged, and then the entire recording was digitally reassembled. Pops and clicks can be heard where bits of the lacquer were missing, but this recording of WNEW’s Join the News Reel from 10 February 1944, broken decades ago, now speaks once more.

Listen here:

Learn more about IRENE at NEDCC.

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The IRENE system at the Northeast Document Conservation Center, mounted on a vibration-damping pneumatic air table. Photo courtesy of Northeast Document Conservation Center.

The Complexity of Color – Creating Digital Surrogates

Researchers and students today have an increasing expectation of being able to find needed materials and information online. Libraries and other cultural heritage institutions have responded by focusing on digitization for both preservation and access to these cultural heritage materials. The Digital Imaging Lab, as part of the Preservation and Digital Conversion Division, is at the center of the creation of digital surrogates for preservation and online access at Columbia University.

Digital surrogates are “faithful” reproductions of an object at the time it is photographed. It is an accurate record of the item’s appearance and condition at a singular point in time. Since we want to handle the material as little as possible, a use-neutral file is created that is large enough to cover the many expected uses of an image file, from viewing on a computer monitor to reproduction in books and journals. But how do we know what is large enough? Back in 2010, in order to ensure a certain level of quality, federal agencies set about writing a set best practices for all those involved with the creation of digital surrogates for the federal government. This became known as The Federal Agencies Digitization Guidelines Initiative or FADGI. These guidelines became the standard for cultural heritage institutions here in America. European institutions adopted similar standards, known as Metamorfoze. In the Digital Imaging Lab we strive to reach the 3 and 4 star ratings parameters set forth in these guidelines (page 10 of the FADGI guidelines has an explanation of the star rating system).

Creating a digital surrogate.

Creating a digital surrogate. Photo credit: David Ortiz.

By far the biggest challenge faced by any institution in the creation of digital surrogates is the capture of accurate color. Color is a highly complex subject. It is thought that the perception of color takes place in the mind as an endpoint of a sequence of physical, physiological and psychological events. Each individual perceives color in his or her own unique way. Just like individuals, every device used in our lab, from the monitors we use to the cameras to the printers, capture and display color differently. Luckily scientists have been studying color for a long time and there exist several models for the mathematical description of color. In the digital realm we use a color model called RGB, named for the red, green and blue light that devices use in capturing and displaying color. Certain amounts of each of these lights (on a scale of 0 to 255) will produce almost all of the colors we can perceive.

Before we can use any device in the Digital Imaging Lab we must first find out how that device captures or displays color, and then, using software, we can bring it to a known state of color capture or display. The process in a nutshell is this:  using scientifically created and widely recognized color targets that have patches of mathematically defined colors, we have the device capture an image of the target (or for a monitor, display a set of defined colors). We note how far off the device is and then create a set of offsets (or corrections) for the device. These offsets are what are typically called color profiles.

This is a very simplified version of what goes into color profiles. The color of the walls, ambient lighting, the position and type of lights being used for photography, all have unique characteristics that must be dealt with when getting ready to create a digital surrogate. Even the pigments in the object being imaged can affect the sensor in unique and surprising ways. Contrary to the wishes of most cultural heritage institutions, creating high quality digital surrogates that have a good chance of persisting long into the future, is never as simple as pushing a button.

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Digital Surrogate of a page from a medieval manuscript, at bottom is a Kodak color target.

A Brief History of the Preservation Reformatting Department

Columbia’s Preservation Reformatting Department (PRD) began as a reprographic services unit back in the 1930s. In the 1970s-1980s, the department gradually became a reprogaphy unit with an emphasis on the preservation of brittle and deteriorating materials.

While the Preservation Division was taking shape, the world was just beginning to understand the slow moving disaster headed our way: the acids within wood pulp paper, which would eventually consume our books and documents. A number of studies done as early as the 1930s had found that an overwhelming percentage of research collections were printed on acidic paper which, under less than pristine conditions, would eventually become embrittled, ensuring the eventual destruction of more than a century of scholarly works.

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Columbia Daily Spectator, Dec. 8, 1941

In an attempt to cope with this looming catastrophe, the National Endowment for the Humanities (NEH) issued a number of grants to research libraries throughout the U.S., including CUL. These funds, along with emerging best practices established by the Research Library Group (RLG), provided us with the means of moving nascent reformatting projects into large scale reformatting programs, which endure to this day, albeit in a much evolved form.

As of 2016, PRD has transformed itself in many ways; a reflection of the revolutionary technological changes happening outside and within the library doors. We continue to prioritize materials in demand but have expanded our capacity. You may be surprised to hear that we still do send out shipments of microfilm for brittle, circulating collections, primarily due to copyright restrictions. We also still create preservation photocopies for materials for which we really need physical copies on the shelves, such as music scores and reference materials.

In addition, we have a fully developed program for ebook creation for public domain materials and PRD staff is responsible for every step of this process, as they have been for many years with microfilming and photocopying. The staff collates items, searches for existing copies, creates copy catalogued records for the new formats, sends and receives vendor reformatted materials, and is responsible for all QC, image processing and uploading and organizing on Internet Archive.

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A pamphlet from the Missionary Research Library (Burke Library)

A future blog post will explore this process and some of the customizations and enhancements that PRD has come up with over the years.

Finally, we are also responsible for the front end of patron services and for numerous special projects, such as the Columbia Spectator digitization project and Burke’s Missionary Research Library digitization, images of which are included in this post.

Welcome to The Long View!

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Photographers and conservators work together to image a 17th-century medical book. Photo credit: David Ortiz.

Welcome to the Columbia University Libraries’ Preservation and Digital Conversion Division blog.  In our work preserving and imaging the Libraries’ diverse collections, we are privileged to work with remarkable materials and amazing people, as well as some awesome tools. As these activities take place in laboratories and spaces that are closed to the public, this blog will be a forum to share our work with the Columbia University community and beyond.  We hope you will find our observations and discoveries informative and that you will engage with us through the comments section. We want to hear from you!

You may be wondering, what do we mean by “The Long View”? In a division that focuses on both the tangible and the digital, our days are spent engaging with the past, with an eye towards the future. Cutting-edge technology is applied to unique items of cultural heritage; new acquisitions are prepared for circulation; research into historical artistic processes is paired with twenty-first century analytical equipment—all with the goal of increasing access and understanding. How do we make a fragile manuscript, a 17th-century medical pop-up book, or rare Chinese paper gods available to scholars and students? How will we ensure they are still accessible in the future? And what can the original materials and techniques used to make these items tell us about their history, provenance, and significance? These are the questions we ask and the challenges we enjoy. We are not the first to care for these collections, nor will we be the last. So we take the long view, actively engaging the past with the present, and securing its perpetuation into the future.

And now, a message from our director, Janet Gertz:

Established in 1974, the Columbia University Libraries Preservation and Digital Conversion Division is one of the oldest comprehensive preservation departments in the country. We are responsible for preserving Columbia University Libraries’ collections in all formats and genres and we achieve our charge by using a variety of tools to prevent or ameliorate damage and deterioration or, if that is not possible, to reformat. We take an active role, in collaboration with our colleagues throughout the Columbia University Libraries, to assure the ongoing stewardship of Columbia’s world class collections. In addition, we collaborate with colleagues outside of the Columbia community to improve and promote preservation nationally and internationally.