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

1. A picture decoding device with a motion compensation prediction comprising:

a candidate list construction unit configured to select a plurality of blocks each having one or two pieces of motion information containing at least information about a motion vector and information about a reference picture from a plurality of neighboring decoded blocks of a decoding target block and to construct a candidate list containing candidates of the motion information used for the motion compensation prediction from the motion information of the selected blocks;

a first motion information deriving unit configured to derive from a first candidate contained in the candidates first motion information in a first direction;

a second motion information deriving unit configured to derive from a second candidate different from the first candidate contained in the candidates second information in a second direction different from the first direction; and

a selected candidate generator configured to generate a first new candidate of the motion information by combining the first motion information and the second motion information, wherein

the first motion information deriving unit further derives from the second candidate third motion information in the first direction,

the second motion information deriving unit further derives from the first candidate fourth information in the second direction,

the selected candidate generator generates a second new candidate of the motion information by combining the third motion information and the fourth motion information, and

the candidate list construction unit includes the motion information derived from the motion information of the block of a picture temporally different from the picture including the decoding target block in the candidate list.

2. A picture decoding method with a motion compensation prediction comprising:

selecting a plurality of blocks each having one or two pieces of motion information containing at least information about a motion vector and information about a reference picture from a plurality of neighboring decoded blocks of a decoding target block and constructing a candidate list containing candidates of the motion information used for the motion compensation prediction from the motion information of the selected blocks;

deriving from a first candidate contained in the candidates first motion information in a first direction;

deriving from a second candidate different from the first candidate contained in the candidates second information in a second direction different from the first direction;

generating a first new candidate of the motion information by combining the first motion information and the second motion information;

deriving from the second candidate third motion information in the first direction;

deriving from the first candidate fourth motion information in the second direction; and

generating a second new candidate of the motion information by combining the third motion information and the fourth motion information; and

including the motion information derived from the motion information of the block of a picture temporally different from the picture including the decoding target block in the candidate list.

3. A non-transitory computer-readable recording medium having embedded thereon a picture decoding program with a motion compensation prediction, the picture decoding program causing a computer to execute:

selecting a plurality of blocks each having one or two pieces of motion information containing at least information about a motion vector and information about a reference picture from a plurality of neighboring decoded blocks of a decoding target block and constructing a candidate list containing candidates of the motion information used for the motion compensation prediction from the motion information of the selected blocks;

deriving from a first candidate contained in the candidates first motion information in a first direction;

deriving from a second candidate different from the first candidate contained in the candidates second information in a second direction different from the first direction;

generating a first new candidate of the motion information by combining the first motion information and the second motion information;

deriving from the second candidate third motion information in the first direction;

deriving from the first candidate fourth motion information in the second direction; and

generating a second new candidate of the motion information by combining the third motion information and the fourth motion information; and

including the motion information derived from the motion information of the block of a picture temporally different from the picture including the decoding target block in the candidate list.