An image sensing device comprising: image sensor means having an array of pixels arranged in rows and columns, each said pixel of the array being operable to produce an electrical output signal in dependence upon light incident on the pixel concerned, and the pixels of the array including one or more shaded pixels that are shielded from such incident light and also including effective pixels that are not shielded from such incident light; a plurality of analog-to-digital conversion units, each corresponding to a different one of the pixel columns, and each operable to receive the respective output signals of pixels of the corresponding column and to subject the received output signals to analog-to-digital conversion so as to produce digital signals dependent on the received signals; characterized by: a feedback control unit (200; 400; 500) configured to output an offset compensation signal (Wda) dependent on an amount of error between a reference value (Dcp) and the digital signal produced by at least one said analog-to-digital conversion unit based on the output signal of at least one said shaded pixel; and a plurality of offset compensation units (104; 201), each arranged on an input side of one of the plurality of analog-to-digital conversion units, and each for performing offset compensation by subtracting the offset compensation signal (Wda) from the output signal of an effective pixel before that signal is subjected to said analog-to-digital conversion. image sensor means having an array of pixels arranged in rows and columns, each said pixel of the array being operable to produce an electrical output signal in dependence upon light incident on the pixel concerned, and the pixels of the array including one or more shaded pixels that are shielded from such incident light and also including effective pixels that are not shielded from such incident light; a plurality of analog-to-digital conversion units, each corresponding to a different one of the pixel columns, and each operable to receive the respective output signals of pixels of the corresponding column and to subject the received output signals to analog-to-digital conversion so as to produce digital signals dependent on the received signals; characterized by: a feedback control unit (200; 400; 500) configured to output an offset compensation signal (Wda) dependent on an amount of error between a reference value (Dcp) and the digital signal produced by at least one said analog-to-digital conversion unit based on the output signal of at least one said shaded pixel; and a plurality of offset compensation units (104; 201), each arranged on an input side of one of the plurality of analog-to-digital conversion units, and each for performing offset compensation by subtracting the offset compensation signal (Wda) from the output signal of an effective pixel before that signal is subjected to said analog-to-digital conversion. a feedback control unit (200; 400; 500) configured to output an offset compensation signal (Wda) dependent on an amount of error between a reference value (Dcp) and the digital signal produced by at least one said analog-to-digital conversion unit based on the output signal of at least one said shaded pixel; and a plurality of offset compensation units (104; 201), each arranged on an input side of one of the plurality of analog-to-digital conversion units, and each for performing offset compensation by subtracting the offset compensation signal (Wda) from the output signal of an effective pixel before that signal is subjected to said analog-to-digital conversion.