Hyperspectral Imaging (HSI) or Chemical Imaging (CI) is the combination of spectroscopy, imaging data acquisition and digital image processing.

A fairly good and introducing overview of chemical and hyperspectral imaging is given by the respective Wikipedia pages: Chemical Imaging and Hyperspectral Imaging.

In medicine and life sciences, imaging procedures (e.g. computer tomography) are just as established as spectroscopy is for chemical analyses in the industrial area (e.g. sorting machines).

Until now, imaging methods can only gather a limited and specialized data. However, spectroscopic procedures, which analyze the characteristics of radiation (e.g. the wavelengths of light) can gather much more data than mere imaging, but are only able to depict said data in punctiform (e.g. a single wavelength as a single pixel).

With our innovative hyperspectral cameras, we provide the advantages of both technologies integrated into one easy-to-handle system. Thus, chemical characteristics, acquired via spectroscopy, are recorded as 2-dimensional pseudo color images. This improved data processing is called Chemical Color Imaging Technologie.
It surpasses mere data acquisition and, in a further step, combines chemometric analysis, color image analysis and color imaging with standardized image processing algorithms.
Our hyperspectral camera systems record more than 100 spectral channels. These channels include the visible spectral range (VIS) as well as the invisible near infrared range (NIR).

Accordingly, not only the acquired data, but also the information value of the recorded images is very high. That way, images recorded with our hyperspectral camera systems provide chemical information, such as water, starch, fat or chlorophyll levels, tissue oxygenation, tissue segmentation, germ load, tissue hemoglobin index etc.

All of this opens up entirely new and diverse application areas in medicine, life sciences and industry. We provide the users of our hyperspectral imaging systems with an important and new possibility for analyses and diagnostics.

 

Principle of an imaging transmission spectrometer

 

Principle of an imaging transmission spectrometer

Principle of an imaging transmission spectrometer

The schematic above shows the design and the functionality of an imaging transmission spectrometer, which is integrated into our HSI camera systems. The spectrometer unit consist of an entrance slit, two imaging optics, a holographic transmission grid and an area sensor. Via the entrance objective and the entrance slit, the light remitted by the object reaches the first lens of the spectrometer unit.
The lense focusses the light and before it reaches the transmission grid, where it is broken into single wavelengths. After that, the light reaches the area sensor of the CMOS camera via a second lense.
Due to the design of the spectrometer unit, a spatial dimension (width of the object as X-axis) is acquired. The scanning unit itself provides the second spatial dimension: length of the object as Y-axis. It moves the entrance slit, thereby scanning the whole object lengthwise within seconds. A third, spectral dimension is given by the recorded wavelengths.
Thus, a 3D data cube, as depicted in the following schematic, is generated.

3D-DataCube

3D-Datenwürfel

 

The HSI camera is based on hyperspectral imaging technology and generates tree dimensional data cubes (X [spatial dimension], Y [spatial dimension], λ [spectral dimension]).
The 3D data cubes are the basis for the extraction of the chemical information the images contain.
In the schematic above shows the absorption spectra of a specific pixel and an image which was extracted from the spectral dimension at a specific wavelength.
Thus, it is possible to extract the specific wavelength for every single pixel of an image acquired with our hyperspectral camera system and use the information for detailed analysis or diagnostics.