An image data generation device for a vehicle, communicates with a server that recognizes an image in at least one of a basic map data, an aerial photograph data, and a navigation map data, recognizes an image data generated by an in-vehicle camera, and generates a travelling trajectory data for autonomous driving. The image data generation device for the vehicle includes: a segment image data generation unit that generates an image data for each segment as a segment image data from an image data generated by an in-vehicle camera; and a data transmission unit that transmits the segment image data generated by the segment image data generation unit to the server.