초록 ▼

An image coding apparatus provides a run-length encoding unit RLE1 that subjects quantized coefficients which are obtained by quantizing frequency components of an image signal to a variable length coding process by using a run value Run that indicates the number of successive zero coefficients and

An image coding apparatus provides a run-length encoding unit RLE1 that subjects quantized coefficients which are obtained by quantizing frequency components of an image signal to a variable length coding process by using a run value Run that indicates the number of successive zero coefficients and a level value Lev that indicates a value of a non-zero coefficient following the zero coefficients. The run-length encoding unit RLE1 includes a reordering unit Lreodr for reordering level values Lev; a variable length coder LVLC for coding reordered level values ROLev by using a code table that is selected according to the value of a quantization parameter QP; a reordering unit Rreodr for reordering run values Run from high frequency component of the quantized coefficients to low frequency component; and a variable length coder RVLC for coding reordered run values RORun by using a code table that is selected according to the number of already-processed run values.

대표청구항 ▼

1. A coding method for coding a coefficient of a frequency component included in a target block to be coded, the coding method comprising: transforming the coefficient of the frequency component into a run value and a level value;coding the level value; andcoding the run value,wherein said coding of

1. A coding method for coding a coefficient of a frequency component included in a target block to be coded, the coding method comprising: transforming the coefficient of the frequency component into a run value and a level value;coding the level value; andcoding the run value,wherein said coding of the run value includes:counting a number of zero-value coefficient with a frequency component which is not higher than a frequency component corresponding to a zero-value quantized coefficient related to the run value to be coded;selecting a code table in accordance with the counted number of zero-value coefficient; andvariable length coding the run value by using the selected code table. 2. The coding method according to claim 1, wherein the coding method for coding the coefficient of the frequency component is performed on a block by block basis. 3. A coding apparatus which codes a coefficient of a frequency component included in a target block to be coded, the coding apparatus comprising: a transforming unit operable to transform the coefficient of the frequency component into a run value and a level value;a level value coding unit operable to code the level value; anda run value coding unit operable to code the run value,wherein the run value coding unit includes:a number counting unit operable to count a number of zero-value coefficient with a frequency component which is not higher than a frequency component corresponding to a zero-value quantized coefficient related to the run value to be coded;a table selecting unit operable to select a code table in accordance with the counted number of zero-value coefficient; anda variable length coding unit operable to variable length code the run value by using the selected code table.