A method for digitizing an analog quantity (V E) produced by a detector of electromagnetic radiation, in particular infrared radiation, said detector comprising a matrix of juxtaposed elementary sensors, whose interactions with said radiation generate said analog quantity (V E), the method comprising the steps consisting, for each line or for each column of said matrix: - in carrying out a first integration phase of said analog quantity over a first time interval using an integrator stage; - in ordering the interruption of said first integration phase via a comparator stage whereof one input is connected to the output of said integrator stage and the other input to a reference circuit delivering a reference value (V ref); - in converting the analog quantity thereby integrated (V S) to a first numerical value via a binary counter and a memory element connected to the output of said comparator stage; - in storing said first numerical value in the form of a first binary number representing the most significant bits; said method being characterized in that it further comprises the steps consisting, for each line or for each column of said matrix: - in converting said first numerical value thereby obtained to an analog signal (V DAC) similar to the analog quantity to be digitized (V E) via an analog-to-digital converter; - in subtracting said analog signal (V DAC) from said analog quantity to be digitized (V E); - in amplifying the signal (V E - V DAC) resulting from said subtraction with a gain representing said first numerical value; - in carrying out a second integration phase using said integrator stage, in order to produce a second numerical value proportional to the analog signal thereby amplified 2 B.(V E - V DAC) and forming a second binary number representing the least significant bits; - in adding said first and second numerical values in order to form a number representative of said analog quantity to be integrated (V E). - in carrying out a first integration phase of said analog quantity over a first time interval using an integrator stage; - in ordering the interruption of said first integration phase via a comparator stage whereof one input is connected to the output of said integrator stage and the other input to a reference circuit delivering a reference value (V ref); - in converting the analog quantity thereby integrated (V S) to a first numerical value via a binary counter and a memory element connected to the output of said comparator stage; - in storing said first numerical value in the form of a first binary number representing the most significant bits; - in converting said first numerical value thereby obtained to an analog signal (V DAC) similar to the analog quantity to be digitized (V E) via an analog-to-digital converter; - in subtracting said analog signal (V DAC) from said analog quantity to be digitized (V E); - in amplifying the signal (V E - V DAC) resulting from said subtraction with a gain representing said first numerical value; - in carrying out a second integration phase using said integrator stage, in order to produce a second numerical value proportional to the analog signal thereby amplified 2 B.(V E - V DAC) and forming a second binary number representing the least significant bits; - in adding said first and second numerical values in order to form a number representative of said analog quantity to be integrated (V E).