| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a variable length coding method capable of improving the efficiency of coding when a coefficient value is coded. <P>SOLUTION: The variable length coding method includes: a coefficient scan step of changing coefficient values on two-dimensional columns of a block into coefficient values on one-dimensional columns; an RL column conversion step of converting the coefficient values on the one-dimensional columns into a combination of run value and level value; a first coding step of performing variable length coding on the run value; and a second coding step of performing variable length coding on the level value while switching a plurality of tables. In the second coding step, when the absolute value of a non-zero coefficient value L to be encoded exceeds a threshold assigned to a table used, after switching to a table to which a threshold greater than the threshold is assigned, a non-zero coefficient value L to be encoded next to the non-zero coefficient value L to be encoded is encoded and switching of the plurality of tables is unidirectional switching. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
