1. A feature image detecting method of detecting a feature image and presenting a detection result, the feature image detecting method using a database in which correction case examples regarding feature images in the past are stored, and an image difference detecting means, where the feature image detecting method is carried out by at least one processor unit and comprises: inputting as a subject video to be examined, a video after carrying out a correction with respect to the feature image; detecting whether or not the feature image is contained in this video; if the feature image is not contained, the image difference detecting means calculating a scene feature quantity sequence of: a subject scene including a plurality of frame images for a video before correction and a corresponding scene including a plurality of frame images for the video after correction, on the basis of feature quantities of frame images within the scenes, comparing chronological lists of respective scene feature quantities of the scene feature quantity sequences of the two videos while shifting a comparing start position of the two videos with respect to each other by each predetermined amount of a plurality of predetermined amounts, detecting a difference in the scene configurations of the two videos from a difference in the lists of the scene feature quantities, detecting a correction method on a basis of difference in the scene configurations, and storing the same in the database.