Category Archives: Glossary


JSTOR/Havard Object Validation Environment (JHOVE) is software used for format identification, validation, and characterization of digital images during post scanning tasks.Whereas the validation process establishes the level of compliance of the digital image to the specifications of its purported formats. It checks the well-formedness, validity, and consistency of digital objects. Format characterization determines the salient features of a given object. JHOVE uses standards established by Open Archival Information System (OAIS) reference model ISO/IEC 14721 to report information such as digital image file path/URL, last modification date, byte size, format, format version, MIME types./span>

To conclude, the JHOVE tool supports routine identification, validation, and characterization of digital images stored in digital repositories.

HS Code

Harmonized systems codes (HS codes) are standardized numerical ways of classifying globally traded products. They are widely used during export and import goods. Administered by the World Customs Organization and updated every five years, HS codes are used by customs authorities throughout the world to identify products when assessing internal taxes and gathering data. The book2net book scanners fall under HS Code 84718000.



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.

Freight Insurance

This is the additional protection that covers shipped goods in cases of loss or damage. Standard carrier policy covers blanket amounts and does not adjust according to freight value. An independent insurance policy offers full value protection of shipment and helps clients to avoid the heavy task of proving liability should there be damages. Since book2net scanners are valuable goods, adding an insurance policy particularly for international shipments assures our customers that their goods are covered in case of any eventuality.

In addition, good freight insurance policies may offer coverage excluded by carrier limitations, including civil commotions, and strikes. Moreover, the value of the packed goods isn’t limited to the carrier’s bill of lading nor do they have to prove that damages or losses arising as the carrier’s fault.

Freight costs

These are costs incurred to ship scanners from our factory in Bad-Nauheim, Germany to an agreed client’s location. While book2net incoterms are ex works, we do help customers to arrange to ship at their own costs. We have partnered with dedicated transport service companies like Ontour Transport Services GmbH to support our customers in shipping their orders worldwide, whether by land, sea, or air.

The freight costs depend on variables like mode of shipping, i.e. land, sea, or air, the distance between pick-up and destination, the weight and packing density, and fluctuating market prices.


DPI stands for ‘Dots per Inch’ “, more precisely the print-dots per inch and describes the dot density. So 300 dpi means a printer puts out 300 tiny dots of ink to fill in every inch of the print. In image reproduction, the dot density is a measure of the level of detail in a rasterized, visual reproduction and thus one of the quality aspects of the technical reproduction process.. This means that dpi is the technical printing resolution with which the print data is handled on a carrier medium. The dpi number depends on the specific printer.

In common parlance, there is no longer a distinction between dpi and ppi. In fact, even in the technical jargon of media designers, the terms are largely used synonymously. PPI describes the resolution in pixels in a digital image, whereas dpi describes the number of (print-)dots in a printed image.


CRI stands for Color Rendering Index and describes in numbers to what extent artificial light is similar to natural light. In color theory, white is the maximum range of red, green and blue. In nature, perfect white is achieved when sunlight falls vertically on the earth at noon, that is, no wave areas are broken off into the atmosphere. In this case we speak of a CRI of 100. Reflections, on the other hand, take place in the evening and in the morning; the sky turns red, which means that the blue components of the light are broken off by the atmosphere.

With book scanners, developers try to get as close as possible to the value 100 for the light source, usually a CRI of 80-95 is achieved. However, this value is not solely responsible for the quality of the light; valid statements can only be made in connection with the color temperature. The values can also fluctuate depending on the current operating temperature of the light source.

Continuous Light

Continuous light is understood in artistic photography as an artificial light source that illuminates a motif over a longer period of time. One of the advantages is that, in contrast to natural light, there can be no light fluctuations. The distance between the subject and the lamp as well as the output of the continuous light lamp have an influence on the brightness of the object to be exposed. Another advantage of artificial permanent lighting is that the quality of the photo can be recognized before the actual picture is taken, since shadows and brightness can be regulated by adjusting the height. This is particularly important in analog photography. The disadvantage, however, is that the continuous light can produce color distortions, especially if a little daylight is also involved.

Our systems use sustainable and gentle LED lighting: by default, it is only switched on during the scan and slowly raised and lowered within a second to protect the operator’s eyes. This mode of operation extends the service life of the LEDs, which are generally very long-lived, even further.

Image sensor / CMOS versus CCD

There are two types of image sensors for industrial cameras on the market: CCD and CMOS sensors.

Both, CCD sensors (Charge Coupled Device) and CMOS sensors (Complementary Metal Oxide Semiconductor) convert light (photons) into electrical signals (electrons).In terms of performance, CMOS sensors have now not only caught up with CCD sensors, but also outperformed them. The main difference between the two types of sensors lies in their technical design.

Let’s first compare how the two sensor types work:

Camera sensors use picture elements called “pixels” to detect light. A common analogy when it comes to pixels is to imagine a series of buckets collecting rainwater.

The big difference happens when you read out the sensor!

Area sensor bucket analogy

CCD image sensors read out each pixelsequentially.

In our bucket analogy water is poured from one bucket to the next like an old-fashioned fire brigade.

CCD sensor bucket analogy

CMOS image sensors read out each pixel in parallel. This means that CMOS cameras can read 100 times faster than a comparable CCD camera..

CMOS sensor bucket analogy

As a result of the integrated evaluation electronics, CMOS sensors offer the following advantages compared to CCD:

– Very high frame rates compared to a CCD of the same size
– Significantly lower power consumption
– Artifacts. i.e. unintentionally created differences to the image source, such as blooming and smearing typical for CCD do not occur.
– Lower need for light: Sensitive historical documents and books can be digitized particularly gently, as the light intensity can be significantly reduced during capture.
– Due to the flexible read out through direct addressing of the individual pixels, CMOS sensors offer more options for binning & partial scan/ ROI.
-Smaller size of the camera, as the evaluation logic can be integrated on the same chip (system on a chip)


In art history, especially painting research, underdrawing describes a preliminary drawing carried out by the artist, which is located directly on the primer of the picture carrier and is covered by one or more layers of paint. It can therefore usually not be perceived by the human eye. The term underdrawing is used to differentiate the more general term preliminary drawing, which also includes preliminary studies by an artist that were made separately on paper or cardboard.

Older paintings are mostly signed in some form. Art history distinguishes between two basic techniques:

  1. The scratching with a needle, as can be found especially in medieval paintings with gilded grounds

  2. The use of painting and drawing materials, such as those used for hand drawings, including graphite, charcoal, chalk, ink, Indian ink and white lead (opaque white)

The visualization of underdrawings harbors great potential for research in art history with regard to questions about the creation processes (work genesis), the materials used and the execution techniques as well as attribution and authenticity (original or copy).

Today, with the methods of multispectral photography, especially infrared reflectography (formerly also infrared photography), different layers and painting materials of a painting can be made visible and scientifically analyzed.


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