An image processing device configured to process image data obtained externally, the image processing device comprising: a preprocessing circuit configured to carry out preprocessing during processing of said image data; and a circuit configuration controller configured to carry out partial reconfiguration of the preprocessing circuit for processing of said image data; the preprocessing circuit including: a plurality of arithmetic converter circuits (232, 234, 236) configured to perform arithmetic computations on said image data to convert the image data; and a timing control circuit (231, 233, 235) provided between each one in the plurality of arithmetic converter circuits (232, 234, 236) connected in order of processing, the timing control circuit (231, 233, 235) configured to secure the reliable exchange of data; wherein the image processing device halts operation of the arithmetic converter circuits (232, 234, 236), the circuit configuration controller partially reconfigures the preprocessing circuit by reconfiguring at least one arithmetic converter circuit (232, 234, 236) in the plurality of arithmetic converter circuits while excluding the timing control circuit (231, 233, 235) from reconfiguration, and the image processing device starts operation of the arithmetic converter circuits (232, 234, 236) after circuit reconfiguration processes end for all of the arithmetic converter circuits (232, 234, 236) requiring reconfiguration. a preprocessing circuit configured to carry out preprocessing during processing of said image data; and a circuit configuration controller configured to carry out partial reconfiguration of the preprocessing circuit for processing of said image data; the preprocessing circuit including: a plurality of arithmetic converter circuits (232, 234, 236) configured to perform arithmetic computations on said image data to convert the image data; and a timing control circuit (231, 233, 235) provided between each one in the plurality of arithmetic converter circuits (232, 234, 236) connected in order of processing, the timing control circuit (231, 233, 235) configured to secure the reliable exchange of data; wherein a plurality of arithmetic converter circuits (232, 234, 236) configured to perform arithmetic computations on said image data to convert the image data; and a timing control circuit (231, 233, 235) provided between each one in the plurality of arithmetic converter circuits (232, 234, 236) connected in order of processing, the timing control circuit (231, 233, 235) configured to secure the reliable exchange of data; wherein the image processing device halts operation of the arithmetic converter circuits (232, 234, 236), the circuit configuration controller partially reconfigures the preprocessing circuit by reconfiguring at least one arithmetic converter circuit (232, 234, 236) in the plurality of arithmetic converter circuits while excluding the timing control circuit (231, 233, 235) from reconfiguration, and the image processing device starts operation of the arithmetic converter circuits (232, 234, 236) after circuit reconfiguration processes end for all of the arithmetic converter circuits (232, 234, 236) requiring reconfiguration.