| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a data compression apparatus capable of carrying out novel preferable reversible compression processing applicable to compression of CT data. <P>SOLUTION: The data compression apparatus includes: a difference generating section for generating new data to be compressed by obtaining a difference between adjacent numerals in a sequence of numerals configuring data to be compressed and represented in a prescribed number of unit bits; an offset section for offsetting each numeral configuring the new data to be compressed by a value in response to steepness of a peak in a histogram of the numerals; a division section that separates each numeral of the data to be compressed subjected to offset at the number of divided bits smaller than the number of unit bits in response to the steepness of the peak into a higher-order bit part and a lower-order bit part so as to divide the data to be compressed into the higher-order data comprising a sequence of the higher-order bit parts and a sequence of the lower-order bit parts; and a higher-order compression section and a lower-order compression section for respectively applying reversible compression processing to the higher-order data and the lower-order data. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
