白平衡根据当前光照条件调整扫描仪的相机，以确保色彩温度均匀，从而保证图像质量恒定。传感器的色彩灵敏度也因此根据各自的光照条件进行调整。
对白色的感知强烈依赖于环境和相应光源。例如，在日光下，纯白色看起来比在荧光灯下更冷，在荧光灯下它看起来更绿。即使在受控环境中，这也可能成为一个问题。
尽管人眼或大脑可以适应各自的光照情况，并几乎直观地进行白平衡并补偿偏色，但数码相机却无情地再现它们：例如，如果数码相机设置为日光模式，并且在人造光下拍照，图像将呈现红色。
因此，在安装过程中直接进行用户定义的白平衡可从一开始就保证准确的色彩。由于照明环境的变化总是需要新的白平衡，因此在使用行星式扫描仪时通常应确保恒定且均匀的照明条件。
白平衡应通过对尽可能白色或至少中性灰色的表面进行全幅扫描来实现。通常使用普通的白纸进行此操作，但白纸通常含有光学增亮剂，因此可能导致偏色并产生失真结果。
因此，在book2net，我们使用高精度、光谱中性的白平衡目标，以确保在本地照明条件下实现精确的用户自定义机内白平衡。
相关主题
水印是纸张中一种识别性的图像或图案，当通过透射光（或在深色背景下通过反射光）观察时，它会呈现出不同深浅的明暗度，这是由纸张厚度或密度变化引起的。
Watermarks have been traceable for handmade paper since the 13th century, originally serving as trademarks of the manufacturing paper mills. Since the screens for paper production only had a limited service life and paper was usually not stored for long due to its high price, it is possible to date historical papers very precisely by determining datable watermarks and comparing them with the deviations caused by the manufacturing process. For this reason, filigranology (watermarking) has established itself as a forensic auxiliary science for historical sciences, especially in art history, to determine the age, origin and authenticity of documents and graphic works of art using watermarks. For this purpose, extensive historical collections have been created since the beginning of the 20th century, many of which are now available as databases. Watermarks on papers that have been damaged, poorly preserved or extensively painted over can also be made visible again with the help of modern analysis methods such as multispectral photography.
Discover our filterless multispectral camera system!
Nowadays, watermarks are mainly used as security features on bank notes, postage stamps, and other government documents to discourage counterfeiting.
In the course of digitization, however, imperceptible markings and information in media files that can only be detected with certain methods are referred to as “digital watermarks”. As with traditional watermarks, the document and watermark information should be inextricably linked. There is a separate process for each type of media (images, audio, video), which is adapted to the respective coding and data format. At book2net, too, we offer special software modules to protect digital copies with individual digital watermarks.
Related Topics
The genesis of a work of art, i.e. the creation process, can be made visible via forensic examination using multispectral photography. Watermarks, signatures and the analysis of techniques, image carriers, color materials and paper structures can provide information about the places and modes of origin as well as the artistic work process. Scientific research often receive important information about the dating and authenticity of a work of art (original or copy), but also about artistic and ec