| 摘要 |
A data compressing method and a data decompressing method, and a data compressing apparatus and a data decompressing apparatus employ a splay coding instead of an arithmetic coding to achieve a high speed code entering process. The data compressing apparatus encoding input data according to a history of occurrence of the input data in the past to compress it, includes a pre-data retaining unit (100) retaining a context, a history retaining unit (101) retaining a combination of input data and a context, a code tree retaining unit (102) retaining code trees each independent for each context, a code tree determining unit (103) determining a code tree, a code outputting unit (104) outputting unique data according to bifurcation from a node on the code tree, a code tree rearrangement unit (105) exchanging an encoded leaf with another leaf or an internal node, and a pre-data updating unit entering the data in the pre-data retaining unit (100). |
