An imaging device includes: an imaging unit; an imaging time information storage unit configured to store imaging time information for each imaging direction; and a distribution information generation unit configured to sequentially acquire frames from an image signal, cut out partial image information of a preset cutout range, generate distribution image information, specify an imaging direction with the longest imaging time at a predetermined determination timing, determine whether the partial image information of the cutout range acquired when the specified imaging direction is captured is included in an imaging angle of view after an imaging direction has changed, and when it is determined as being included, cut out a range corresponding to the partial image information of the cutout range acquired when the specified imaging direction is captured, from a frame to be acquired subsequently, thereby generating the distribution image information.