Nonuniformity correction scheme considering the effects of internal thermal stray light

Abstract

Abstract. A stray light compensated nonuniformity correction (SLCNUC) method is proposed for infrared (IR) cameras. The proposed approach formulates thermal stray light compensation functions according to the internal temperature changes of the IR camera. To derive the compensation functions, we analyze the variations of the NUC parameters over the entire range of internal temperatures and determine the function coefficients by using a least squares method. Compared with the existing NUC methods used in previous studies, the major advantage of the proposed method is its effective reduction of nonuniformity even in highly accumulated thermal stray light situations. Experiments and comparisons performed with real IR images show that the proposed method maintains lower spatial noise over a wide internal temperature range of the IR camera. It is shown that the proposed NUC achieves an 18 dB higher peak signal-to-noise ratio than that of the conventional reference-based NUC method. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Colour imaging system response non-uniformity correction based on inverse model and regularization method

“…There are two kinds of non-uniformity correction (NUC) methods for imaging systems. One is calibration-based method 1–15 and the other is scene-based NUC method. 16–44 The NUC model is the most important factor in both methods.…”

“…However, the imaging system response non-uniformity included a lot of factors, which come from optical system, detector, imaging electronics system and so on. 12–15,45 Detector response has randomness because of manufacture. It can be modelled by the random process.…”

“…12 At the same time, optical system is also an important factor for the system response non-uniformity. 13–15,45 Especially for visible imaging systems, the non-uniformity caused by optical system is even more serious than the non-uniformity caused by detector-related factors. Moreover, most of visible imaging systems have the nonlinear response characteristic; it also brings difficulties to correct the non-uniformity.…”