An image processing apparatus (1) is adapted to carry out a heavy-load operation that requires a longer processing time as compared with other ordinary operations. The apparatus comprises multiple heavy-load processing units (14, 15, 16, 17) arranged in parallel with each other, a data distribution unit (13) configured to distribute image-related data to each of the heavy-load processing units, and a data synthesizing unit (18) configured to synthesize multiple data sets output from the heavy-load processing units so as to produce a sequence of heavy-load processed data that is substantially the same as one obtained if a single heavy-load processing section were employed.