Block diagram of IRLMS
Improved IRLMS and phase correlation
We are developing several simple and effective scene-based nonuniformity correction (SBNUC) techniques to adaptively compensate the FPN according to the scene information (no calibration targets). Our approaches are featured by fast convergence rate (less than 20 frames or even only use 2 frames), high steady-state accuracy, robustness to "ghosting artifacts" and computational simplicity. Those methods can be integrated with the hardwares of the infrared cameras to make them more robust to the temporal drift of the FPN which may occur slowly over time. With those SBNUC technologies, we have successfully developed several ‘smart' infrared cameras, including two cooled thermal imager [3-5μm, HgCdTe IRFPA] with resolution 320×256 and 640×512, respectively; and two uncooled thermal imager with resolution 320×240 and 640×480 (8-14μm, VOx Microbolometer).
We present a simple and effective scene-based nonuniformity correction (NUC) method for infrared focal plane arrays based on interframe registration. This method estimates the global translation between two adjacent frames and minimizes the mean square error between the two properly registered images to make any two detectors with the same scene produce the same output value. In this way, the accumulation of the registration error can be avoided and the NUC can be achieved. The advantages of the proposed algorithm lie in its low computational complexity and storage requirements and ability to capture temporal drifts in the nonuniformity parameters. The performance of the proposed technique is thoroughly studied with infrared image sequences with simulated nonuniformity and infrared imagery with real nonuniformity. It shows a significantly fast and reliable fixed-pattern noise reduction and obtains an effective frame-by-frame adaptive estimation of each detector’s gain and offset.
The simplest and most efficient registration-based SBNUC!
Improved interframe registration based nonuniformity correction for focal plane arrays (Improved IRLMS)
Scene based nonuniformity correction based on block ergodicity for infrared focal plane arrays
A two-frame approach for scene-based nonuniformity correction in array sensors
Registration Method Under FPN
Registration method for infrared images under conditions of fixed-pattern noise
New temporal high-pass filter nonuniformity correction based on bilateral filter
Scene-based nonuniformity correction method using multiscale constant statistics