Technology Bootcamp January 18, 2014 Large-Scale Digital Libraries Digitization Process Krystyna K. Matusiak, Ph.D. Assistant Professor Library & Information Science Program

Overview Large-scale digital libraries (DLs)  The National Science Digital Library (NSDL)  HathiTrust  Europeana  The Digital Public Library of America (DPLA) Digitization as a conversion process Fundamental questions  What?  Why?  How? Digitization as a multi-step process Digitization standards and guidelines  The notion of archival master files and derivatives  Image capture: technical factors Digitization technology Overview of Digitization2

LARGE-SCALE DIGITAL LIBRARIES Overview of Digitization3

Large-Scale Digital Libraries Massive aggregations of scientific and cultural heritage content with millions of digital objects  Offer a new centralized approach to providing access to scientific and cultural materials  Aggregate content (or metadata) from smaller individual DLs and provide portals for global searching and retrieval  Address the limitations of the resource discovery in the DL environment  Build upon over two decades of extensive digitization efforts Types of content  Born-digital  Digitized Overview of Digitization4

Large-Scale Digital Libraries Sources of content  Local digitization: Individual DLs created by academic and public libraries, archives, historical societies, and other cultural heritage and research organizations  Mass digitization: Google Book Project; Open Content Alliance Information ecosystem – multilayered trusted networks Models  Distributed (DPLA, Europeana, NSDL)  Centralized (HathiTrust) Coverage Goals  Expanding access  Supporting digital preservation Overview of Digitization5

The National Science Digital Library (NSDL) 6

HathiTrust 7

Europeana 8

The Digital Public Library of America (DPLA) 9

DIGITIZATION PROCESS How have we created this critical mass of digitized content? Overview of Digitization10

Overview of Digitization11 Digitization is a process of conversion of analog information into a digital format through scanning or digital photography. It is a multi-step process that involves selection, image capture, creation of descriptive and technical metadata, and digital preservation of the objects created as a result of the conversion process.

Basic Digitization Workflow Digitization is More than Scanning Digitization Overview12 Selection Image capture Digital processing Indexing and metadata Ingesting Preservation and maintenance

What? Manuscripts * Books *Journals *Maps Overview of Digitization13

What? Archival Materials Overview of Digitization14

What? Cultural Heritage Materials on Tape and Film Overview of Digitization15

Why? Expand access – 24/7 Provide access to unique primary sources held in local archives Extend search capabilities of digital text Improve resource discovery Provide access to high-resolution images Integrate resources in multiple modes of representation Bring together dispersed collections Assist preservation and conversation efforts Overview of Digitization16

How? General Guidelines Digitize at the highest resolution appropriate to the nature of the source material  Avoid rescanning and handling of the originals in the future Create digital objects that are accessible and interoperable across platforms and devices  High-quality  Consistent  Authentic Produce digital objects that support the intended current and future use  Build a repository of digital master files to facilitate reprocessing and maintaining digital collections over time  Provide derivative access files for current use Create backup copies of all files on servers and have an off- site backup strategy Overview of Digitization17

Digital Master Files Created as a direct result of the image capture process either through scanning or photographing with a digital camera Should represent the visual information of the original material Serve as a long term archival file and a source for derivative images  Digital masters are not used for online delivery or print output General recommendations for digital master file creation include :  Scanning at the highest quality affordable  No compression or lossless compression  Non-proprietary archival formats TIFF – text or still images WAV – audio AVI or Motion JPEG 2000 or MXF – moving images * * Unlike text, still image, or audio, there is no archival file format that has been definitively established for moving images Overview of Digitization18

Examples  Photographic print 5x7 in. scanned in RGB mode at 600 ppi → 35 MB TIFF file, e.g. kw tif  Large map 63 x 56 cm. (24. 8 x 22 in.) scanned in RGB mode at 300 ppi → 185 MB TIFF file, e.g. am tif  Monograph page 23 cm (approx. 9 in.)scanned in RGB mode at 400 ppi → 25 MB TIFF file, e.g. 001_Front cover.tif Digital Masters

Derivative Files Created from digital master files for specific use including  Access images for digital collections or other types of Web delivery  User requests  High resolution prints General recommendations for derivative files :  Reduce the resolution depending on the intended use  72 dpi or 96 dpi for Web access  300 dpi for print output or for high-resolution viewers  Compress files to reduce their size  Select appropriate access formats PDF – text JPEG or JPEG still images MP3 – audio MPEG-4 (MP4) or QuickTime or Real Video – moving images Overview of Digitization20

Image Capture Technical Factors Mode of capture  Bitonal — one bit per pixel representing black and white  Grayscale — multiple bits per pixel representing shades of gray  RGB (red-green-blue) — multiple bits per pixel representing color File formats  Tiff  JPEG  JPEG2000  RAW and DNG No compression Compression  Lossless  Lossy 21

Image Capture Technical Factors Resolution (ppi – pixels per inch; dpi – dots per inch)  An image 1500 x 2100 pixels displayed at 100 ppi = ? in.  The same image 1500 x 2100 pixels displayed at 300 ppi = ? in Bit depth  The number of bits used to represent each pixel determines how many colors can appear in a digital image 22 Source: BCR’s CDP Digital Imaging Best Practices.

Digital Masters – Photographs and Text Scanning Specifications Source: Wisconsin Heritage Online Digital Imaging Guidelines (2009). Version 2.0. Original materialScanning resolution Bit depthApproximate scanned dimensions Approx. size of preview image Photographs 16” x 20” +200 ppi24-bit color6400 x 8000 pixels146 MB 8 ½” x 11”–16” x 20”300 ppi24-bit color3200 x 4000 pixels36 MB 8” x 10”400 ppi24-bit color3200 x 4000 pixels36 MB 5” x 7”625 ppi24-bit color3200 x 4000 pixels36 MB 4” x 5”800 ppi24-bit color3200 x 4000 pixels36 MB 4” x 2 ½”1200 ppi24-bit color3200 x 4000 pixels36 MB Text Print—no images600 ppi1-bit bitonalVaries Print—with images300 ppi8-bit grayscale or 24-bit color Varies Manuscript400 ppi8-bit grayscale or 24-bit color Varies

Scanners Source materials in a variety of formats require versatile scanning equipment  Photographs (reflective and transparent materials)  Photographic prints → flatbed scanners  Film negatives and slides → film scanners, flatbed scanners with transparency adapters  Text (reflective materials)  Single leaf documents → flatbed scanners, sheet-fed scanners  Bound materials → overhead scanners or digital cameras  Oversize materials (reflective materials)  Maps, charts, etc. → large format scanners or digital cameras  Microfilm (transparent)  Newspapers → microfilm scanners Overview of Digitization24

Book scanner for Book, Oversized Prints and Maps DSLR for Oversized Prints, Maps, Scrolls, and 3D objects Film and Slide scanner Film and Slide Scanner with auto-feeder Flatbed scanner for Prints, Glass, and Transparent objects Video conversion Audio conversion Large format scanner for maps and oversized materials 25Overview of Digitization

Resources General Digitization Guides, Standards, and Best Practices Association for Library Collections & Technical Services (ALCTS). (2013). Minimum Digitization Capture Recommendations. capture-recommendationshttp:// capture-recommendations BCR’s CDP Digital Imaging Best Practices (2008). [updated version of Western States Digital Imaging Best Practices] BCR CDP Digital Imaging Best Practices_2008.pdf Besser, Howard. Introduction to Imaging, Revised Edition (2003). The J. Paul Getty Trust. This book is free as a downloadable PDF. A Framework of Guidance for Building Good Digital Collections. 3rd Edition (2007). NISO Framework Advisory Group. Handbook for Digital Projects: A Management Tool for Preservation and Access. (2000). Northeast Document Conservation Center. Moving Theory into Practice: Digital Imaging Tutorial. (2000). Cornell University Library/Research Department. The NINCH Guide to Good Practice in the Digital Representation and Management of Cultural Heritage Materials. (2002). The National Initiative for a Networked Cultural Heritage (NINCH). CDP Digital Imaging Best Practices_2008.pdf 26Overview of Digitization