1. An image encoding method using an adaptive preprocessing scheme, comprising: loading an input image for each frame; determining an encoding type of each of the frames; determining a size of a block to be encoded in each frame according to the determined encoding type; determining blocks that can be replicated from the blocks having the determined size and performing an intra-picture replication preprocessing or inter-picture replication preprocessing procedure on the determined blocks according to the encoding types of the frames; and encoding the frames on which the preprocessing procedure has been performed.