SoPC implementation of combined real-time non-uniformity correction of IRFPA

Abstract

With the increase of pixel density and scale of IRFPA (Infrared Focal Plane Array), NUC (Non-Uniformity Correction) technology becomes more and more important to access high quality infrared images. However, traditional one-point or two-point NUC methods based on calibration technology can't achieve ideal performance because they can't overcome the non-linearity and drift of the detector response parameters in both spatial and temporal regions effectively. A novel combined real-time non-uniformity correction method is proposed based on FPGA (Field Programmable Gate Array) technology, which adopts SoPC (System-on-a-Programmable Chip) architecture based on Nios II processor core to implement the total NUC processing functions inside only one chip. The NUC processing chooses the reference-based binomial fitting algorithm to remove the main non-uniformity of the detector, and the remained non-uniformity is compensated by using the improved scene-based temporal high-pass filter algorithm. The experiment results show that the combined method based on SoPC architecture can access the ideal efforts with IRFPA size of 320×240×14bit @ 25 frames per second. The block diagram of hardware circuit and the processing flow are described in details.