To make obtainable desired images and information in a simple way and with a high efficiency by tracking the image change in a specific area in regard to a time series image and extracting the image when its change of a prescribed degree is caused in the specific area.

In a sports relay program such as a baseball, the information showing the progress of a game including the innings, scores, the number of outs, etc., are generally displayed at each specific position on a screen. Then, the area of an image where the above information is shown at a certain point of time is designated as an image extracting area and at the same time the image data included in the designated area are registered within a key image storage part 19. The following images are successively extracted in the areas set by the designated conditions and then compared with the key image registered at the part 19. Then an image obtained when a change of a prescribed degree is caused to the key image is extracted as the image that is corresponding to the occurrence of an event.