Image decoding device and motion vector decoding method, and image encoding device and motion vector encoding method

An image decoding device comprising:

• a lossless decoding unit configured to obtain predicted horizontal block information and predicted vertical block information from compressed image information, the predicted horizontal block information indicating a block having motion vector information selected as predicted horizontal motion vector information from decoded blocks adjacent to a current block, the predicted vertical block information indicating a block having motion vector information selected as predicted vertical motion vector information from the decoded adjacent blocks;
• a predicted motion vector information setting unit configured to set the predicted horizontal motion vector information that is motion vector information about the block indicated by the predicted horizontal block information, and set the predicted vertical motion vector information that is motion vector information about the block indicated by the predicted vertical block information;
• and
• a motion vector information generation unit configured to generate motion vector information about the current block by using the predicted horizontal motion vector information and predicted vertical motion vector information set by the predicted motion vector information setting unit.