Filter method, dynamic image encoding device, dynamic image decoding device, and dynamic image encoding/decoding device

A filter method that carries out filter processing on a plurality of blocks contained in an image comprises: determination steps (S201, S202) for determining whether each of the plurality of blocks are IPCM blocks; a filter step (S204) for carrying out filter processing on a block among the plurality of blocks that is not an IPCM block, i.e. a non-IPCM block, and generating filtered data; and output steps (S204, S205) for outputting the filtered data as a pixel value of the non-IPCM block, and outputting the pixel value of the IPCM block, which has not undergone filter processing, as a pixel value of the IPCM block.