1. A computer-readable recording medium on which an image processing program that is executed by a computer is recorded, the image processing program comprising: reading process of reading a plurality of image data items that have been photographed and acquired by a plurality of cameras; and editing process of extracting image data items of which dates and times of photography overlap within a same time band from among the plurality of image data items that have been read, and generating a data item for playback by editing the plurality of extracted image data items.