Eliminating non-uniformity is a persistent challenge for infrared imaging systems, especially when the integration time varies. This paper describes a non-uniformity correction method with the ability to adapt to arbitrary changes in integration time by correcting the infrared radiation flux map of the scene, which is estimated by pixel-wise radiometric self-calibration. Multiple images of an extended blackbody, obtained with different integration times and blackbody temperatures, were used to obtain the parameters of both the correction model and radiometric calibration model. The correction effect of this method within a wide range of integration times was verified by a high-resolution HgCdTe medium-wave infrared imager.