An in-vehicle image processing apparatus capable to link to multiple cameras (101,102,103,104) mounted to a vehicle, the image processing apparatus comprising: an image memory that stores multiple image data captured by each of the multiple cameras (101,102,103,104); a camera-image acquisition unit that inputs and stores the multuple image data captured by each of the cameras (101,102,103,104) into the image memory; 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 each of the image data stored in the image memory on the projection surface, and converts the combined image data into two-dimensional image data based on the viewing information determined by the viewing movement controller; a display unit that displays the two-dimensional image data converted by the image converter; and a periodic rendering trigger generator that generates a trigger signal to make the image converter start an image conversion process; characterized by further comprising a viewing transition-regulation memory that stores the viewing transition regulations, wherein the viewing transition regulation stored in the viewing transition-regulation memory includes start-point viewing information, end-point viewing information and viewing interpolation regulations, and the viewing movement controller continuously changes the viewing information based on the start-point viewing information, the end-point viewing information, and the viewing interpolation regulation in the viewing transition-regulation memory. an image memory that stores multiple image data captured by each of the multiple cameras (101,102,103,104); a camera-image acquisition unit that inputs and stores the multuple image data captured by each of the cameras (101,102,103,104) into the image memory; 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 each of the image data stored in the image memory on the projection surface, and converts the combined image data into two-dimensional image data based on the viewing information determined by the viewing movement controller; a display unit that displays the two-dimensional image data converted by the image converter; and a periodic rendering trigger generator that generates a trigger signal to make the image converter start an image conversion process; characterized by further comprising a viewing transition-regulation memory that stores the viewing transition regulations, wherein the viewing transition regulation stored in the viewing transition-regulation memory includes start-point viewing information, end-point viewing information and viewing interpolation regulations, and the viewing movement controller continuously changes the viewing information based on the start-point viewing information, the end-point viewing information, and the viewing interpolation regulation in the viewing transition-regulation memory.