An image processing system includes image processors. Each image processor outputs image data of one of color components that the image processor is in charge of to an image forming unit. Each image processor includes an accumulator that accumulates transferred image data of the color components; a generator that processes rendering data, and, for a corresponding page, generates image data of the color components; a transfer controller that transfers the image data to the accumulator when the accumulator is normal and to another accumulator when the accumulator has a defect, and, when the accumulator is normal, further transfers to the other image processors the image data of color components whose output is taken charge of by the other image processors; and an output controller that outputs the accumulated image data and the transferred image data of the color component in an order of pages to the image forming unit.