1. A method of controlling a stability of response of a semi-conductor matrix imager comprising a plurality of pixels, the method comprising: a first phase of characterizing the stability, the first phase comprising: irradiating the pixels with a gauge radiation that is constant over time for a first predetermined duration; storing signals delivered by each pixel at regular time intervals for the first predetermined duration; determining, for each pixel, an amplitude distribution of the signals delivered by each pixel; characterizing each distribution with a statistical indicator representative of a dispersion of the distribution; and classifying each pixel, on the basis the indicator for the pixel, into one of at least two categories of pixels, each category being representative of the stability of the temporal response of the pixels, the first category representing stable pixels, and the second category representing unstable pixels; and a second phase of correcting the stability, the second phase comprising: associating each unstable pixel with one or more stable pixels according to a predetermined criterion; irradiating the pixels with a radiation to be characterized for a second predetermined duration; storing signals delivered by each pixel for at least one time interval during the said second predetermined duration; and correcting a signal generated by each unstable pixel as a function of a signal or signals generated by the stable pixels associated with the said unstable pixel.