Category Archives: B

Book fold optimization

Some books, especially books with a thick spine, have a deep book fold when opened. When viewed from the side or front, the pages are usually very curved, making it difficult to take a true-to-scale and distortion-free image. Since our scanning systems digitize vertically from above and have a high depth of field, no information is lost despite the strong curvature. Only the text may show a slight curvature in the digital copy in such cases. This cannot be changed physically and is independent from the optics used. In order to still obtain an optimal result, our software offers the optional function “book fold optimization”. It recognizes the text and “equalizes” it so that each letter is on a straight line and the text is optimally readable. The deep book fold and the curved text are thus displayed in the best possible way.

Attention: This function is a subsequent image manipulation, which improves the optical perception, but does not match the content of the original. Basically, all our systems are designed to create a color-accurate and true digital copy of the original. Such a subsequent manipulation no longer complies with this principle.

Book formats

Book formats have changed over the centuries and vary from country to country. It is therefore necessary to have a flexible scanning system in order to be able to carefully digitize a wide variety of formats.

The book format indicates how many sheets a book printer can create from one sheet of paper, which is traditionally based on the dimensions of a Roman parchment sheet. An unfolded sheet is called an atlas format, double folio or large folio. Folding the sheet a first time provides a folio format (2 sheets), folding it a second time provides a quarto format (4 sheets), and so on. The size varied depending on the availability of the skins that were processed into parchment.

In letterpress printing from the 15th to 19th centuries, the format was also determined by the number of folds of the paper sheet. However, the size of the paper sheet varied regionally according to the respective measurement system. Sheet sizes between 20 × 30 and 30 × 40 cm were common. In addition, the book size varied by the amount of trimming after binding. The ratio of height to width varied depending on the type of folding. In the 6°, 12° and 24° formats, the width is narrower in relation to the height than in the 2°, 4°, 8° and 16° formats.

German standards

Since 1883, efforts were made in Germany to standardize sheet sizes. 12 standard formats were introduced, of which number 1 measured 33 × 42 cm unfolded. For the bibliographic description of books, the Prussian Instructions (PI) were established, which defined standardized book sizes. The old designations folio, quarto, octavo, etc. were adopted, but defined differently. Only the height of the spine was used for classification, without regard to the sheet folding and proportion, based on the space-saving library arrangement of books of the same height on shelves.

In general, formats according to PI are considerably larger than according to the traditional definition. Thus, an octavo volume according to PI is up to 25 cm high, including also quarto, octavo, duodecimo and all smaller formats according to traditional understanding. In other countries, other rules applied.

Due to different printing, binding and cutting techniques, the size of the finished book varies. Therefore, the German Library in Frankfurt a. M. has created the following guideline:



Spine Height

gr. 2°


over 45 cm


40–45 cm

gr. 4°


35–40 cm


30–35 cm

Lex. 8°


25–30 cm

gr. 8°


22,5–25 cm


18,5–22,5 cm

kl. 8°


15–18,5 cm



10–15 cm

Specification in centimeters

< 10 cm

Today, libraries in German-speaking countries mostly use the Rules for Alphabetical Cataloging (RAK) created in 1976, which are based on the International Standard Bibliographic Description (ISBD). According to this, the height of the book spine is given in centimeters during cataloging without specifying a format category. In addition to the height, booksellers and antiquaries often also specify the width of a book or a format category. The latter also applies to some foreign classification.

Book cradle

The book cradle is a device that facilitates the digitization, filming or copying of bound originals, for example books, archive files, newspaper volumes or magazines. It ensures that the adjacent pages of bound originals are brought to the same height, regardless of the thickness of the original and regardless of the position at which a bound original is opened. In this way, the same distance to the imaging unit (scanning system) is achieved for both sides, a necessary prerequisite for ensuring optimum scanning results.

In contrast to conventional copiers or flatbed scanners, the book does not lie on a book cradle with the page to be digitized facing downwards, but with the text mirror facing upwards.

There are many different designs of such devices. The decisive factor for selecting the right book cradle is ultimately the material to be processed. Valuable historical materials such as old prints and illuminated manuscripts require a different type of book cradle than modern books, magazines or journals. Likewise, parameters such as condition, state of preservation, binding, or size and weight are often decisive for how far bound materials can be opened at all without causing damage to the binding or spine.

For this reason, a wide variety of book cradles are available to digitize books optimally, also from a conservation point of view. Basically, they can be divided into the following categories:

  • Simple book supports made of foam
  • Mechanical or motorized book cradles with a 180° opening angle
  • Mechanical or motorized V-shaped book cradles that only allow a reduced opening angle <= 110°.
  • Mechanical or motorized hybrid systems whose opening angle can be variably adjusted

Depending on the design, professional book cradles also have other additional features that ensure gentle handling of the originals:

Glass plate:As the pages should lie as flat as possible during scanning, book cradles are often equipped with a glass plate that should press the pages of the originals to be scanned as much as possible.

Book spine release: This refers to a special mechanism that is used to set a gap several centimeters wide between the individual support plates of the book cradle, into which the spine can be gently inserted. Modern scanning systems usually allow an adjustment that can be individually adapted to the respective original.

Book spine support: This is a mechanism below the area of the support plates that provides support for the inserted spine and prevents smaller books from slipping through the open gap when the spine is released.

Book support

A book support is a simple device to adjust the height for scanning. For this, the bound template lies on two foam sheets. These have to be adjusted and replaced again and again in order to compensate for the height differences that arise between the left and right pages of the book when turning the pages of bound templates.



Good price-performance ratio for institutions such as small archives which only have to digitize bound documents sporadically.

The book support can simply be put aside when it is not needed.

book2net repro stand with book support


  • Not suitable for larger scan jobs
  • Cumbersome to use. Many different foam sheets in thickness and width are required to optimally support various templates and materials.
  • Often very limited template height
  • Limited format width

Book scanner

In contrast to document or passage scanners, book scanners are so-called overhead or reflected light scanners, which were primarily designed for the gentle, contactless digitization of bound documents such as books, journals and magazines. Special components such as gentle light control from above (incident light), a book cradle with book spine exemption and a gentle glass pressure procedure avoid unnecessary stress on the documents during the scanning process and possible consequential damage. Usually, book scanners are also combined with special software that processes the digital copies and allows the user to save them in the desired format.

Book scanners are nowadays used worldwide in the public area of archives, libraries and administrations as a replacement for conventional copier systems (e.g. reading rooms, authorities, law firms, etc.). In addition, they are used in the service sector to process on-demand orders (university interlibrary loan) or extensive digitization projects. In addition to purely manually operated systems, semi or fully automatic scanners (scan robots) are also offered.

Book scanners with modern surface sensor technology are among the most innovative, gentle and reliable systems. They deliver the highest image quality as well as extraordinary scanning speed and image processing processes. In addition to quality and investment security, this can mean considerable time, cost and staff savings, especially when conducting large projects.

In cooperation with the British Library and the National Archives of Sweden, MICROBOX developed the first book scanner in 2006 under the book2net product line. Since then we have continuously expanded our portfolio and today we offer our customers application-specific hardware and software as complete solutions that cover all areas: DIN A5 or DIN A0 format, single sheet or precious handwriting, matt or glossy surface, flat or raised Structures, two-dimensional or 3D objects. From standardized digitization to special applications and professional multispectral photography: the MICROBOX / book2net team offers customer-specific solutions for all areas.

Book spine release

Book spine release refers to a special manually, mechanically or motor-controlled device with which a gap of several centimeters is set between the individual support plates of the book cradle, into which the book spine can be gently inserted. Modern scanning systems usually allow a setting that can be individually adapted to the respective template.
Often, a book spine release is also combined with a book spine support, which supports the inserted book spine from below the area of the support plates. It also prevents smaller books from slipping through the open gap.

book2net book cradle


Book bindings which are very similar to today’s existed as early as the first century AD.Before, written manuscripts were mainly kept as scrolls. The earliest bound collections of loose leaves are called “codices”. They were collected using Coptic binding, in which several layers of paper are bound together by intertwining a thread.
Then, as early as the 2nd century, books with a soft binding appeared. These early specimens are most comparable to our modern paperbacks; they had either no binding at all or a soft parchment or paper binding. Later, bookbinders began experimenting with wooden bindings, often covered with leather.
The oldest bound book in the Western world is the St. Cuthbert Gospels, dated to the 8th century AD and now a part of the holdings of the British Library. Scientific research, including a CT scan, provided detailed insights into the structure of the book. A clay-like material was found between the leather and the wooden boards, which raised the pattern on the cover.
As medieval bookbinding evolved, staples were added to some books to stabilize them. Similar bindings were found on books with parchment covers. However, since parchment is very sensitive to moisture, books were increasingly bound with cloth.
Nowadays we carry the world’s knowledge around in our smartphones, but in earlier centuries it could only be stored and passed on in books. Between the 13th and 16th centuries, the rate of those who were able to read increased, and this was followed by an innovative way of binding books: the girdle book. These books had a second cover over the leather binding, with which they could be fastened to a belt. This allowed the educated, wealthy bourgeois population to carry books (mainly religious texts) with them at all times.

Over time, books became more and more elaborate. The invention and spread of paper made it possible to produce books in editions that had not been possible before. These continuous developments also required a certain degree of automation in the binding process. In order to keep pace with the increasing demand, both the materials used and the techniques had to be revised. In the course of industrialization in the 19th century, books were no longer bound exclusively by hand. Increasingly, publishers took over the entire process of book making, from printing to binding. Books were printed on brittle paper, and by the end of the century, almost all books received a cloth binding. Many libraries re-bound these books, although nowadays attempts are made to preserve the old bindings.
By the 20th century, bookbinding was fully mechanized and glue replaced thread to hold the pages together. But not everyone was enthusiastic about this. Bookbinders see their craft as an art instead of an industry. To counter this, bookbinders continue to communicate the value of traditional techniques. There are competitions that impressively convey the art of the craft; an art form that always strives for perfection.

Book types

A book (Latin liber), according to traditional understanding, is a collection of printed, written, painted or even blank sheets of paper or other suitable materials, which is bound and usually equipped with a cover or jacket.

There are different types of books. They can be divided according to the type of production (brochure, hardcover) or according to the content (encyclopedia, travel guide, novel, etc.). There are also numerous special cases (e.g. audio book, blank book, artist’s book). Even books from everyday life do not make the classification easier (cash book, guest book). In addition, there are a number of products that are printed and bound, but are not called books (calendars, magazines, etc.).

In the digital age, the term book has also been applied to electronic publications (e-book).


Blooming is an effect that usually occurs with older, digital cameras with CCD sensors. Light points and stripes on the image are common for this effect. These are caused by overexposed areas, as the sensor’s pixels are only able to absorb a certain amount of charge. The excess amount of charge is released to neighboring pixels, creating a bright spot in the form of a stripe.






The white stripe below the sun is a result of the bloomig effect. On the other hand, the roundish white spot around the sun is caused by scattering of light in the atmosphere and optics and has nothing to do with blooming.

Source: Wikimedia Commons Copyright: Public domain 

What can you do about it? So-called anti-blooming gates can be installed in the sensor, which release excess charge. However, this reduces the sensitivity due to the larger pixel size. Long exposure times can result in overexposure, as the charge will drain before a storage cell is full. CCD sensors are therefore rarely provided with these gates, as they are often used for light-sensitive pictures.

Bayer Matrix (Bayer Sensor)

The Bayer matrix is the spatial arrangement of the red, green and blue pixels on a color sensor. A single pixel cannot capture all wavelengths, only the primary colors. Therefore, there are three different types of pixels, called RGB, on a sensor. Without offsetting, this would lead to a loss of 2/3 of the liquidation.

A color sensor of 30 MP, for example, delivers 30 MP color information. This is achieved in that the blue pixel fetches the missing color information red and green from the nearest pixel and uses this information to calculate the real color. This creates 30 MP color information, each from the three values of the basic colors. This process is called demosaicing and the offsetting is the know-how of the camera manufacturer. However, since many different sensors have to be calculated, the Bayer standard has been agreed upon. Here 50% green, 25% blue and 25% red pixels are used.

This division of colors corresponds roughly to that in nature. There are also different methods, for example Sony uses two different shades of green.