1. An image discrimination apparatus comprising: a feature extracting unit to extract a feature indicating a feature of an image from an image signal; a distance calculating unit to calculate a distance between features from a feature currently extracted by said feature extracting unit and a feature extracted last time by said feature extracting unit; a threshold calculating unit to calculate a statistics value of distances between features which have been calculated by said distance calculating unit, and for calculating a threshold for determination of cut points from the statistics value; and a cut point determining unit to compare the distance between features calculated by said distance calculating unit with the threshold calculated by said threshold calculating unit to determine a cut point from a result of the comparison, wherein the threshold for determination of cut points is calculated based on an equation: 
 Th i — n =avg i (Dist n )+α*var i (Dist n ) where avg i (Dist n ) is an average of the distances, α is a coefficient, and var i (Dist n ) is the variance of the distances.