Book scanning

Book scanning or book digitization (also: magazine scanning or magazine digitization) is the process of converting physical books and magazines into digital media such as images, electronic text, or electronic books (e-books) by using an image scanner. Large scale book scanning projects have made many books available online.

Digital books can be easily distributed, reproduced, and read on-screen. Common file formats are DjVu, Portable Document Format (PDF), and Tagged Image File Format (TIFF). To convert the raw images optical character recognition (OCR) is used to turn book pages into a digital text format like ASCII or other similar format, which reduces the file size and allows the text to be reformatted, searched, or processed by other applications.

Image scanners may be manual or automated. In an ordinary commercial image scanner, the book is placed on a flat glass plate (or platen), and a light and optical array moves across the book underneath the glass. In manual book scanners, the glass plate extends to the edge of the scanner, making it easier to line up the book's spine.

A problem with scanning bound books is that when a book that is not very thin is laid flat, the part of the page close to the spine (the gutter) is significantly curved, distorting the text in that part of the scan. One solution is to separate the book into separate pages by cutting or unbinding. A non-destructive method is to hold the book in a V-shaped holder and photograph it, rather than lay it flat and scan it. The curvature in the gutter is much less pronounced this way. Pages may be turned by hand or by automated paper transport devices. Transparent plastic or glass sheets are usually pressed against the page to flatten it.

After scanning, software adjusts the document images by lining it up, cropping it, picture-editing it, and converting it to text and final e-book form. Human proofreaders usually check the output for errors.

Scanning at () is adequate for conversion to digital text output, but for archival reproduction of rare, elaborate or illustrated books, much higher resolution is used. High-end scanners capable of thousands of pages per hour can cost thousands of dollars, but do-it-yourself (DIY), manual book scanners capable of 1200 pages per hour have been built for US$300.

Commercial book scanners

Commercial book scanners are not like normal scanners; these book scanners are usually a high quality digital camera with light sources on either side of the camera mounted on some sort of frame to provide easy access for a person or machine to flip through the pages of the book. Some models involve V-shaped book cradles, which provide support for book spines and also center book position automatically.

The advantage of this type of scanner is that it is very fast, compared to the productivity of overhead scanners.

Large-scale projects

Projects like Project Gutenberg (est. 1971), Million Book Project (est. circa 2001), Google Books (est. 2004), and the Open Content Alliance (est. 2005) scan books on a large scale.

One of the main challenges to this is the sheer volume of books that must be scanned. In 2010 the total number of works appearing as books in human history was estimated to be around 130 million. All of these must be scanned and then made searchable online for the public to use as a universal library. Currently, there are three main ways that large organizations are relying on: outsourcing, scanning in-house using commercial book scanners, and scanning in-house using robotic scanning solutions.

As for outsourcing, books are often shipped to be scanned by low-cost sources to India or China. Alternatively, due to convenience, safety and technology improvement, many organizations choose to scan in-house by using either overhead scanners which are time-consuming, or digital camera-based scanning machines which are substantially faster and is a method employed by Internet Archive as well as Google. Traditional methods have included cutting off the book's spine and scanning the pages in a scanner with automatic page-feeding capability, with subsequent rebinding of the loose pages.

Once the page is scanned, the data is either entered manually or via OCR, another major cost of the book scanning projects.

Due to copyright issues, most scanned books are those that are out of copyright; however, Google Books is known to scan books still protected under copyright unless the publisher specifically prohibits this.

Collaborative projects

There are many collaborative digitization projects throughout the United States. Two of the earliest projects were the Collaborative Digitization Project in Colorado and NC ECHO – North Carolina Exploring Cultural Heritage Online, based at the State Library of North Carolina.

These projects establish and publish best practices for digitization and work with regional partners to digitize cultural heritage materials. Additional criteria for best practices have more recently been established in the UK, Australia and the European Union. Wisconsin Heritage Online is a collaborative digitization project modeled after the Colorado Collaborative Digitization Project. Wisconsin uses a wiki to build and distribute collaborative documentation. Georgia's collaborative digitization program, the Digital Library of Georgia, presents a seamless virtual library on the state's history and life, including more than a hundred digital collections from 60 institutions and 100 agencies of government. The Digital Library of Georgia is a GALILEO initiative based at the University of Georgia Libraries.

In the twentieth century, the Hill Museum and Manuscript Library photographed books in Ethiopia that were subsequently destroyed amidst political violence in 1975. The library has since worked to photograph manuscripts in Middle Eastern countries.

In South Asia, the Nanakshahi trust is digitizing manuscripts of Gurmukhī script.

In Australia, there have been many collaborative projects between the National Library of Australia and universities to improve the repository infrastructure that digitized information would be stored in. Some of these projects include, the ARROW (Australian Research Repositories Online to the World) project and the APSR (Australian Partnership for Sustainable Repository) project.

Destructive scanning methods

For book scanning on a low budget, the least expensive way to scan a book or magazine is to cut off the binding. This converts the book or magazine into a sheaf of separate sheets which can be loaded into a standard automatic document feeder