1. A moving picture reproduction apparatus comprising: a motion vector search module configured to search for motion vectors between input moving picture frames with respect to predetermined pixel blocks; a major vector detection module configured to detect a first major vector which is a motion vector included among the motion vectors searched for and has a maximal ratio of the number of blocks corresponding to one kind of motion vector to the number of all blocks included in one of the moving picture frames, and to classify a motion vector whose absolute value of difference between the motion vector and the first major vector is a predetermined value or less as a first major vector group together with the first major vector, the major vector detection module being configured to detect a second major vector which is a motion vector included among motion vectors obtained by removing the first major vector group from the motion vectors searched for and whose ratio is a first ratio or more, and to classify a motion vector whose absolute value of difference between the motion vector and the second major vector is the predetermined value or less as a second major vector group together with the second major vector, the major vector detection module being configured to repeat detection and classification in order to detect a plurality of major vectors and classify the motion vectors searched for into a plurality of vector groups; a determination module configured to determine a method in which interpolation frames to be inserted between the moving picture frames are generated; and an interpolation frame generation module configured to generate interpolation frames in the method determined by the determination module, wherein the major vector detection module is configured to classify the motion vectors searched for by the motion vector search module into a major vector group comprising the first major vector group, a non-major vector group comprising motion vectors which are other than zero vectors and not included in the major vector group, and a static vector group comprising motion vectors that are zero vectors; the determination module is configured to determine that the interpolation frame generation module should generate interpolation frames in a first method when a ratio of the number of motion vectors constituting the major vector group to the number of motion vectors constituting both the major vector group and the non-major vector group is a second ratio or more, and to determine that the interpolation frame generation module should generate interpolation frames in a second method when the ratio is less than the second ratio; and the motion vector search module is configured to use, as candidates for a search center vector, major vectors which is detected by the major vector detection module from moving picture frames that are input last, and which include the first major vector, to determine one of the candidates that has a lowest matching value as a candidate center vector, and to search an area around the candidate center vector for a motion vector that has a minimum matching value when the motion vectors are searched for with respect to the predetermined pixel blocks.