Image sensor having N lines of P photosensitive pixels with scrolling and signal integration, a pixel of rank j in a line being constituted by a MOS transistor circuit comprising a line selection input (SEL i) connected to a row addressing conductor (L i) common to pixels of the line and an output connected to a column conductor (Ccj) of rank j common to the N pixels of the same rank j belonging to the different lines, each pixel comprising a photodiode, a node of charge storage, a transfer transistor to enable the charge transfer of the photodiode to the storage node, a transistor for resetting the potential of the storage node, a follower transistor for generating a potential representing the quantity of charges in the storage node, and a line selection transistor for connecting the follower transistor to the column conductor, the sensor comprising a successive addressing circuit of each of the N rows of pixels in order to apply, each time, to P column conductors, on the one hand, P potential of resetting after an overall resetting of all the pixels and, on the other hand, P analog signals corresponding to the integration of charges after a global transfer of charges to the storage node for all the pixels, during the same period of integration T, in the P pixels of the line addressed, and the sensor further comprising signal digitization circuits which comprise, apart from the matrix of N lines of P pixels, N lines of P processing circuits, characterized in that each circuit of treatment ( CT i,j) of rank i in line and of rank j in column comprises: - a respective sampler to perform a double correlated sampling of the signals present on a column conductor of rank j and corresponding to the observation of an image point during the same integration time for all the lines, - an analog-to-digital converting means for providing digital values representing differences between two analog sampled signals, - a digital addition means for adding a signal converted by the conversion means of the processing circuit of rank i in row and j in column and corresponding to a period of integration T with digital signals converted by the processing circuits of preceding ranks in line and corresponding to the observation of the same image point during previous integration periods, the digital addition means of a processing circuit of rank i in line and j in column being connected to an output of a processing circuit of preceding rank i-1 in line to receive therefrom the result of a digital addition carried out during a previous integration and the digital addition means being able to add to this result a digital value resulting from a current conversion analog-digital made by the conversion means; the sensor further comprising a means of extracting the content of the digital addition means of the last line at the end of each integration period. - a respective sampler to perform a double correlated sampling of the signals present on a column conductor of rank j and corresponding to the observation of an image point during the same integration time for all the lines, - an analog-to-digital converting means for providing digital values representing differences between two analog sampled signals, - a digital addition means for adding a signal converted by the conversion means of the processing circuit of rank i in row and j in column and corresponding to a period of integration T with digital signals converted by the processing circuits of preceding ranks in line and corresponding to the observation of the same image point during previous integration periods, the digital addition means of a processing circuit of rank i in line and j in column being connected to an output of a processing circuit of preceding rank i-1 in line to receive therefrom the result of a digital addition carried out during a previous integration and the digital addition means being able to add to this result a digital value resulting from a current conversion analog-digital made by the conversion means;