1. A video decoding device comprising:
an encoded bit data distributor (52) that separates encoded bit data separated from a bitstream into encoded bit data per tile;
one or more tile decoders (54-1 to 54-N) each of which carries out a prediction difference decoding process on encoded bit data per tile separated by the encoded bit data distributor to generate a decoded image per tile; and
one or more tile filters (56-1 to 56-N) each of which carries out a filtering process on the decoded image generated by one of the one or more tile decoders by using a filter per tile shown by a filter parameter separated from the bitstream,
wherein the video decoding device includes:
a demultiplexer (51) that demultiplexes the bitstream into the encoded bit data, filter parameters each showing a filter per a tile which is a rectangular region having a predetermined size, and partitioning control information indicating a partitioning state of an inputted image, which are multiplexed into the bitstream;
an image memory (53) that stores a decoded image on which a filtering process is carried out; and
a decoded image storage (57, 58) that combines the decoded image on which the filtering process is carried out by the one or more tile filters to generate a decoded image per frame according to the partitioning control information separated by the demultiplexer, and that stores the decoded image in the image memory (53), and
wherein when a filter share flag showing whether or not a filter is made to be shared among the tiles is multiplexed into the bitstream, the demultiplexer (51) demultiplexes the bitstream into the filter share flag, and also demultiplexes the bitstream into the filter parameters each showing a filter per tile or a filter parameter showing a filter per frame, and, when the filter share flag separated by the demultiplexer shows that a filter is made not to be shared among the tiles, each of the one or more tile filters carries out a filtering process on the decoded image per tile generated by one of the one or more tile decoders by using a filter per tile shown by a filter parameter separated by the demultiplexer, otherwise, carries out a filtering process on the decoded image per tile generated by one of the one or more tile decoders by using the filter per frame shown by the filter parameter separated by the demultiplexer.

2. A video decoding method comprising the steps of:
separating encoded bit data separated from a bitstream into encoded bit data per tile;
carrying out a prediction difference decoding process on encoded bit data per tile separated in the encoded bit data distribution processing step to generate a decoded image per tile; and
carrying out a filtering process on the decoded image generated in the tile decoding processing step by using a filter per tile shown by a filter parameter separated from the bitstream,
wherein the method further includes
demultiplexing the bitstream into the encoded bit data, filter parameters each showing a filter per a tile which is a rectangular region having a predetermined size, and partitioning control information indicating a partitioning state of an inputted image, which are multiplexed into the bitstream;
combining the decoded image on which the filtering process is carried out by the one or more tile filters to generate a decoded image per frame according to the partitioning control information separated, and storing the decoded image in an image memory (53);
when a filter share flag showing whether or not a filter is made to be shared among the tiles is multiplexed into the bitstream, demultiplexing the bitstream into the filter share flag, and also demultiplexing the bitstream into the filter parameters each showing a filter per tile or a filter parameter showing a filter per frame, and, when the filter share flag separated shows that a filter is made not to be shared among the tiles, carrying out a filtering process on the decoded image per tile by using a filter per tile shown by a filter parameter separated, otherwise, carrying out a filtering process on the decoded image per tile by using the filter per frame shown by the filter parameter separated.