An image processing apparatus is provided that combines image data captured by multiple cameras and displays the resulting image of surroundings of the vehicle to monitor monitoring the surroundings of a vehicle. The image processing apparatus includes: an image memory; a camera-image acquisition unit; a projection surface geometry manager that manages projection surface geometry information including a set of three-dimensional coordinates for a projection surface that is virtually formed to surround the vehicle; a viewing movement controller that determines viewing information so that a viewpoint and a viewing direction relative to the projection surface are continuously transited according to a given viewing transition regulation; an image converter that projects and combines the image data on the projection surface, and converts the combined image data into two-dimensional image data; a display unit that displays the two-dimensional image data; and a periodic rendering trigger generator that generates a trigger signal to start an image conversion process by the image converter.