摘要 |
A picture coding system for a document image data in which a plurality of picture coding methods are subjected to a selection such that document image data is converted so as to obtain an identification code representing the selected coding method and signals obtained by coding the data. The system includes units for detecting and for accumulating code lengths of the codes converted in the respective coding methods, units for detecting and for accumulating a difference between the lengths of the respective codes obtained by the conversion achieved in the coding methods, a storage for storing therein a history of a result of the selection of the preceding coding method, and a change-over judge unit for selecting one of the plural coding methods based on information obtained from the three kinds of units.
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