| 摘要 |
PROBLEM TO BE SOLVED: To simplify an expanding processing at a host side, and to attain a high speed processing by compressing the data of a block into data constituted of a code indicating the prescribed number of bits, reference value, and each data in the block indicated by the prescribed number of bits. SOLUTION: A block data storing means 13 of a data compressing device 12 stores the blocked data of multilevel picture data, a reference value storing means 14 stores a reference value in the block data, a difference data storing means 15 stores a difference between data from the leading byte until the end byte in the block data and the reference value, and difference data necessary number of bit storing means 16 stores a value obtained by encoding the number of bits indicating the maximum value of the difference value data as the necessary number of bits indicating the difference value. A bit aligning means 17 generates a code indicating the necessary number of bits indicating the difference value, the reference value, and each difference data indicated by the necessary number of bits indicating the difference value. A pre-block necessary number of bit/reference value storing means 18 stores the necessary number of bits indicating the difference value and the reference value stored in the data compression of the previous block. |
