PURPOSE: To simultaneously display plural observation images and to obtain the same color reproducibility of TV monitors as well as to obviate the decrease in the number of display dots by synthesizing the other image data with the image data of the 1st observation images data while maintaining the characteristics of the image of this data to form the 2nd image data.

CONSTITUTION: The observation image data and the reduced image data formed by reducing the observation images are recorded on a magneto-optical disk 10 by a controller 4 when an operator of a video processor 1 makes judgment that there is a need for recording the observation images. A CPU 11 reads the program corresponding to various kinds of processing to be executed out of a hard disk 19. The reproduction processing to project the image data recorded on the magneto-optical disk 10 on the high-resolution monitor 23 is executed by this program.