1. An encoding method for encoding an image into a bitstream, the encoding method comprising: deriving one or more candidates for a motion vector predictor used to encode a motion vector of a current block in the image; selecting the motion vector predictor out of the one or more candidates; and encoding an index for identifying the selected motion vector predictor into the bitstream, wherein the deriving includes: generating a first candidate for the motion vector predictor from a first motion vector of each of one or more first adjacent blocks that are adjacent to the current block in a first direction; and generating a second candidate for the motion vector predictor from a second motion vector of each of one or more second adjacent blocks that are adjacent to the current block in a second direction, the second direction being different from the first direction, and wherein the generating of the second candidate includes: determining for each of the one or more first adjacent blocks whether or not the first adjacent block is inter-predicted; and scaling a scalable second motion vector to generate the second candidate, the scalable second motion vector belonging to one of the one or more second adjacent blocks, only when any of the one or more first adjacent blocks are not inter-predicted.