An image generating device configured to provide a cloud service to a head-mounted display via a network is provided. A photographed image receiving section 510 receives a plurality of photographed images photographed in different photographing directions. A panoramic image processing section 530 generates a panoramic image by synthesizing the plurality of photographed images photographed in the different photographing directions. A format converting section 540 converts the panoramic image into an image format suitable for specifications of the head-mounted display. A panoramic image transmitting section 550 transmits the panoramic image after format conversion to the head-mounted display.