1. An image predictive decoder comprising a memory that stores a program executable by the image predictive decoder to: extract, from compressed data where an image is divided into a plurality of regions and encoded, encoded data of identification information that specifies a region that is used to produce a prediction signal of a target region, and encoded data of a residual signal; specify a neighbouring region from among a plurality of neighboring regions that neighbor the target region based on the identification information to produce a prediction signal of the target region from a reconstructed signal by using (i) mode information that specifies an inter-picture prediction method, (ii) a reference picture number, and (iii) a motion vector, all of which are for the specified neighbouring region; restore a reproduction residual signal of the target region from the encoded data of the residual signal; produce a reproduction signal of the target region based on the prediction signal of the target region and the reproduction residual signal; and store the reproduction signal of the target region as the reconstructed signal in the memory.