An encoding device includes a filter unit that performs a filtering processing as to image data, for a line block including image data of a number of lines for generating coefficient data of one line of a sub-band of at least a lowest band component. The filter unit generates a plurality of sub-bands made up of coefficient data broken down by frequency band. The encoding device also includes a storage unit that stores coefficient data generated by the filter unit, for the line block. The encoding device further includes a coefficient rearranging unit that rearranges the coefficient data, for each line block, in an order in which a synthesizing processing, for generating image data by synthesizing the coefficient data of a plurality of sub-bands which have been divided into frequency bands, is to be executed. An encoding unit encodes the coefficient data rearranged by the coefficient rearranging unit.