Shutterless thermal imaging

摘要

Since the dawn of focal plane array (FPA) based thermal imaging, shutterless operation has been considered the holy grail of the thermal imaging world. Until now, the current generation of FPA-based cameras have required frequent shuttered calibration (NUC or Wink) blanking off the incoming image with a 'shutter' or 'flag,' rendering the observer 'blind' to the scene for several seconds at a time. In critical situations such as on-line machine vision, this complete obstruction to vision can be highly inconvenient. Each element in the FPA detector possesses a different gain and offset value, which require continuous adjustment to present a uniform image. Many factors, including external ambient temperature, drift and the temperature of the detector itself lead to fundamental fixed pattern noise in the detector output. This leads to steady deterioration of image quality over time.