Hyperspectral calibration method For CMOS-based hyperspectral sensors

Imec has developed a process for the monolithic integration of optical filters on top of CMOS image sensors, leading to compact, cost-efficient and faster hyperspectral cameras that make the technology attractive for industry. To calibrate the sensor, we introduce a full pixel response model that takes into account the inherent properties of the optical filters. This model is then used to derive a calibration method that enables more accurate and robust measurements of the spectral reflectance of a scene. The calibration method is then extended to take into account the normal manufacturing variations between different sensors to perform an inter-sensor calibration. We experimentally validate this method by scanning reference targets with different types of sensors and demonstrate that accurate and reproducible reflectance measurements are obtained.