Picture encoding method, picture decoding method, picture encoding apparatus, picture decoding apparatus, picture encoding program, and picture decoding program

A picture encoding method that encodes picture information for each area by selecting a reference picture from picture information of a plurality of frames that have been previously encoded and generating a prediction picture, the method comprising:

• a reference motion vector setting step that sets a correspondence relation between a plurality of motion vectors that have been stored in advance and reference picture designation information that designates a reference picture;
• a reference picture selection step that selects the reference picture;
• a reference picture designation encoding step that encodes the reference picture designation information that designates the reference picture;
• a motion vector selection step that selects a motion vector corresponding to the reference picture designation information from the plurality of motion vectors that have been stored in advance;
• a prediction picture generation step that generates a prediction picture from the reference picture using the motion vector selected by the motion vector selection step;
• and
• a differential encoding step that encodes a difference between the picture information of the present area and the prediction picture.

A picture decoding method that decodes picture information for each area by generating prediction pictures from picture information of frames that have been previously decoded, the method comprising:

• a motion vector selection step that selects a motion vector from a plurality of motion vectors that have been stored in advance;
• a prediction picture generation step that generates a prediction picture from a reference picture using the motion vector selected by the motion vector selection step;
• and
• a decoded picture generation step that generates a decoded picture by decoding a difference between the picture information of the present area and the prediction picture.

A picture decoding method that decodes picture information for each area by selecting a reference picture from picture information of a plurality of frames that have been previously decoded and generating a prediction picture, the method comprising:

• a reference motion vector setting step that sets a correspondence relation between a plurality of motion vectors that have been stored in advance and reference picture designation information that designates a reference picture;
• a reference picture designation decoding step that decodes the reference picture designation information that designates the reference picture;
• a reference picture selection step that selects the reference picture;
• a motion vector selection step that selects a motion vector corresponding to the reference picture designation information from the plurality of motion vectors that have been stored in advance;
• a prediction picture generation step that generates a prediction picture from the reference picture using the motion vector selected by the motion vector selection step;
• and
• a decoded picture generation step that generates a decoded picture by decoding a difference between the picture information of the present area and the prediction picture.

A picture encoding apparatus that encodes picture information for each area by generating prediction pictures from picture information of frames that have been previously encoded, comprising:

• a motion vector selection section that selects a motion vector from a plurality of motion vectors that have been stored in advance;
• a prediction picture generation section that generates a prediction picture from a reference picture using the motion vector selected by the motion vector selection section;
• and
• a differential encoding section that encodes a difference between the picture information of the present area and the prediction picture.

A picture decoding apparatus that decodes picture information for each area by generating prediction pictures from picture information of frames that have been previously decoded, comprising:

• a motion vector selection section that selects a motion vector from a plurality of motion vectors that have been stored in advance;
• a prediction picture generation section that generates a prediction picture from a reference picture using the motion vector selected by the motion vector selection section;
• and
• a decoded picture generation section that generates a decoded picture by decoding a difference between the picture information of the present area and the prediction picture.