To highly accurately detect a predetermined object or pattern from an image.

First, it is determined whether an outline or an apex has been detected from a certain image. Then, when the outline or the apex is determined to have been detected from the certain image, a pattern matching processing is performed in an area, surrounded by the outline or the apex detected from the certain image in the image. Then, when it is determined that the predetermined object or the predetermined pattern is shown in the area, detection position information indicating positions related to the area is stored in a storage area. On the other hand, when it determined that the outline or the apex is not detected from the certain image, the pattern matching processing is performed to the image based on the detection position information stored in the storage area.