Image generating device

An image generating device, comprising:

• processing circuitry configured to:
• acquire an image captured by an imaging device to be installed in a water-surface movable body;
• acquire positional information indicative of a position of the water-surface movable body;
• acquire posture information indicative of a posture of the water-surface movable body;
• acquire additional display information including information indicative of a position of a target object;
• generate a synthesized image where a graphic rendering a three-dimensional virtual reality object indicative of the additional display information is synthesized with the captured image based on the positional information, the posture information, and the additional display information;
• estimate a position of the target object at a timing later than a timing at which the additional display information is acquired the latest, based on a speed of the target object included in the additional display information, or a speed of the target object estimated from the additional display information;
• and
• update the rendering of the virtual reality object of the target object in the synthesized image based on a result of the estimation