An image generation device comprising: a plurality of frame memories (220A,..., 220F) adapted to store captured images from a plurality of imaging units (20A,..., 20F); and a multiplexing section adapted to read the captured images of the imaging units (20A,..., 20F) from the frame memories (220A,..., 220F) and multiplex the captured images to generate an image stream, wherein the multiplexing section includes a motion detection portion adapted to detect a motion of a subject in a captured image of at least one of the imaging units (20A,..., 20F), a mode determination portion adapted to set the mode for operating the plurality of imaging units (20A,..., 20F) simultaneously if the amount of the motion detected by the motion detection portion is equal to or greater than a given threshold, and to set the mode for operating the plurality of imaging units (20A,..., 20F) intermittently, wherein the imaging units are operated one after another in an intermittent manner at intervals of a frame, lowering the effective frame rate of each of the imaging units, if the amount of the motion detected by the motion detection portion is smaller than the given threshold, and a control signal generation portion adapted to supply, to the plurality of frame memories (220A,..., 220F), a control signal adapted to control reading of the captured images from the plurality of frame memories (220A,..., 220F) in accordance with the mode set by the mode determination portion. a plurality of frame memories (220A,..., 220F) adapted to store captured images from a plurality of imaging units (20A,..., 20F); and a multiplexing section adapted to read the captured images of the imaging units (20A,..., 20F) from the frame memories (220A,..., 220F) and multiplex the captured images to generate an image stream, wherein the multiplexing section includes a motion detection portion adapted to detect a motion of a subject in a captured image of at least one of the imaging units (20A,..., 20F), a mode determination portion adapted to set the mode for operating the plurality of imaging units (20A,..., 20F) simultaneously if the amount of the motion detected by the motion detection portion is equal to or greater than a given threshold, and to set the mode for operating the plurality of imaging units (20A,..., 20F) intermittently, wherein the imaging units are operated one after another in an intermittent manner at intervals of a frame, lowering the effective frame rate of each of the imaging units, if the amount of the motion detected by the motion detection portion is smaller than the given threshold, and a control signal generation portion adapted to supply, to the plurality of frame memories (220A,..., 220F), a control signal adapted to control reading of the captured images from the plurality of frame memories (220A,..., 220F) in accordance with the mode set by the mode determination portion. a motion detection portion adapted to detect a motion of a subject in a captured image of at least one of the imaging units (20A,..., 20F), a mode determination portion adapted to set the mode for operating the plurality of imaging units (20A,..., 20F) simultaneously if the amount of the motion detected by the motion detection portion is equal to or greater than a given threshold, and to set the mode for operating the plurality of imaging units (20A,..., 20F) intermittently, wherein the imaging units are operated one after another in an intermittent manner at intervals of a frame, lowering the effective frame rate of each of the imaging units, if the amount of the motion detected by the motion detection portion is smaller than the given threshold, and a control signal generation portion adapted to supply, to the plurality of frame memories (220A,..., 220F), a control signal adapted to control reading of the captured images from the plurality of frame memories (220A,..., 220F) in accordance with the mode set by the mode determination portion.