An image processing apparatus controls such that a plurality of additional information of image data are classified into a plurality of objects in accordance with update periods thereof and data of the additional ingenerateation corresponding to each of the classified objects is generated and output in accordance with the corresponding update period of each object, thereby multiplexing the data of the additional information corresponding to each object which is generated and output in accordance with update period thereof, to the input image data. The image processing apparatus demultiplexes the multiplexed data into the image data and the additional information, generates updated image data of the object to be updated from the demultiplexed additional information, and superimposes it to the video image corresponding to the image data.