Multispectral camera systems
Human perception of a surface is influenced by a large number of factors including surface structure, coatings and color. Traditional RGB or monochrome cameras are therefore often not suitable for visual control of high-quality products.
Metamerism is one of the main sources of error in color reproduction. For example, objects that appear identical under artificial LED lighting may differ significantly under sunlight. In order to describe color in a form that is independent of the viewing conditions, we need to measure the reflectance spectrum of a surface. This allows us to predict surface color under arbitrary viewing conditions, minimizing the effects of metamerism.
We develop a multispectral print inspection system in collaboration with an industrial partner. It is composed of 4 RGB line scanning cameras with individual filters, providing a total of 12 color channels, which is sufficient for a robust reconstruction of reflectance data. The system is designed to perform high-speed, spatially resolved color measurements with a precision comparable to traditional spectrophotometers used in spot measurements.