| 摘要 |
PURPOSE:To compress a transmission data efficiently by splitting a coefficient data of an AC component into a low-order coefficient data and a high-order coefficient, assigning a bit number being an integral number of multiple of a 2nd bit number smaller than a 1st bit number to the high-order coefficient data and converting the result into a transmission data. CONSTITUTION:An output signal of a block processing circuit 2 is fed to a cosine conversion (DCT conversion) circuit 3, where 2-dimension cosine conversion is implemented. A (8X8) coefficient table corresponding to the size of an L block is obtained from the cosine conversion (DCT conversion) circuit 3. A coefficient data from the cosine conversion circuit 3 is fed to a weighting circuit 4. As the weight coefficient, 1 is selected for a DC component and the weight coefficient is smaller for higher order AC components. The original AC component coefficient data DC is sent, and the low-order AC coefficient data and the high-order coefficient data included in m-block in 15 AC coefficient data around the DC coefficient data are coded by different rules. |
