An information collecting unit reads encoded moving image data from an information storing unit, decodes part of the moving image data, extracts the number and the magnitudes of motion vectors, the square measure of a region having a low correlation with a preceding/succeeding frame, etc. for each frame, and outputs these items of scene change information to an evaluation function calculating unit. The evaluation function calculating unit calculates the value of a predetermined evaluation function based on the scene change information, and outputs the calculated value to a scene change determining unit. The scene change determining unit determines a frame of a scene change by making a comparison between the calculated value and a threshold value. A scene change information storing unit stores the scene change information used for the determination.