1. An image processing device comprising: circuitry configured to operate as: a predictive motion vector generating unit that sets a co-located block to be not available when a type of a reference picture of a current block is different from a type of the reference picture of a co-located block included in a co-located picture when encoding a current motion vector of the current block used in prediction using correlation in a temporal direction and generates a predictive motion vector of the current motion vector using a reference motion vector referred when generating a predictive motion vector; and a reconstructing unit that reconstructs the current motion vector by adding the predictive motion vector generated by the predictive motion vector generating unit to a difference vector between the current motion vector and the predictive motion vector.