Category Archives: G

Grayscale is an important basis for creating a color profile and calibrating a monitor so that images appear true to color.

They are formed from the 256 colors of an RGB color palette in which the red, green and blue components remain the same in the color value. If R, G and B have the value 0, the color defined by this is a pure black; if all three color components have the value 255, this defines a pure white.

This results in a gradation of different tones between black and white, each of which is identified by a number. An intermediate value, such as 192, defines a gray color of certain brightness. In the palette of a grayscale image, therefore, all 256 colors between 0 and 255 are stored − this means that a total of 256 possible gradations in brightness can occur. All color tones, which are stored accordingly between 0 and 255, result in the different gray tones.

A gray chart is used to measure the dynamic range or tonal value differentiation of a digital camera, scanner or monitor. It is a test chart in which there is a smooth or multi-graded (gray scale chart) transition between dark black and bright white.

In order to ensure a true-to-scale, distortion-free high-quality image when digitizing bound originals, one of the requirements is that the surface of the original must be absolutely flat. For this reason, many professional scanning systems work with additional glass or Makrolon© plate pressure systems.^©.

In addition, to guarantee that books of different thicknesses and states of preservation can also be scanned gently and efficiently using glass plates, professional systems operate with advanced adjustment systems for the glass plate allowing the pressure and travel paths to be set precisely and individually as required.

This is used in particular with high-performance scanners with semi-robotics such as the book2net Cobra, Flash, Mosquito, Hornet and Dragon.

Professional book scanners also offer special non-reflective glass with UV protection (museum glass) to minimize light exposure, especially for valuable originals such as incunabula and manuscripts.

The destruction of culturally and historically significant documents through armed conflicts or natural disasters means irreparable damage to cultural memory. Valuable archive and written material are therefore particularly in need of protection. The amount of archival material and their random locations, however, generally does not allow a significant amount of outsourcing in the event of catastrophes or hazardous situations, as the protected spaces required for this are hardly available. For this reason, the Federal Republic of Germany began in 1961, in accordance with the Hague Convention for the Protection of Cultural Property, to microfilm its valuable archives for security purposes and to store them at central shelter so that they can replace the original documents in the event of irretrievable loss. The microfilming is carried out on behalf of the Federation under the leadership of the Federal Office of Civil Protection and Disaster Assistance (BBK). The archive material is security-filmed on microfilm in accordance with selection criteria defined by the Federal Government and in compliance with specified technical standards.

As part of the conversion of the microfilming devices to digital technology, which was agreed between the Federal Office for Civil Protection and Disaster Assistance (BBK) and the Conference of Heads of the Federal and State Archives Administrations (KLA), tenders for high-performance archive scanners have recently been issued to carry out this major task. We are pleased that several of the central state archives have already decided to purchase our new archive scanner book2net Archive Pro to support this project.

Archive Pro at the Hessian State Archives

Federal security document safeguarding project relies on the versatility of the new book2net archive [...]

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Digitization guidelines

The quality of a digitization process is subject to a wide variety of factors. [...]

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Graphics Interchange Format, GIF, is a bitmap image file format that supports up to 8 bits per pixel for each image thus allowing single images to reference their own color chosen from the 24-bit RGB color space. GIF file format uses a lossless data compression technique to reduce file size without degrading the visual quality. This enables files to be converted to a different file type without loss of quality. As much as GIF supports animations, it is less suitable for reproducing color photographs and images with color gradients.

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JPEG

JPEG (JOINT PHOTOGRAPHIC EXPERTS GROUP) JPEG is a lossy compression format [...]

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JPEG 2000, JP2

JPEG 2000 is a file compression format that uses codes to [...]

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PNG

PNG (Portable Network Graphics) is a file format that contains bitmaps [...]

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TIFF

TIFF (TAGGED IMAGE FILE FORMAT) is a computer file format used [...]

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RAW

Digital raster images consist of a set of a grid of [...]

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