| 摘要 |
<p>PURPOSE:To reduce a generated code amount without enlarging a quantizing step size by turning a quantizing coefficient at low level to zero by a threshold value corresponding to a frequency. CONSTITUTION:Each time the quantizing coefficient are successively inputted to a threshold value discriminating means 104 from the low frequency component while setting the generated threshold value at zero as the initial value for each block, a threshold value generating means 107 increases the generated threshold value for a prescribed value and outputs it. In a means 104, the threshold value inputted from the means 107 is compared with the absolute value of the quantizing coefficient inputted from a quantizing means 103, when the absolute value of the quantizing coefficient is larger than the threshold value, the coefficient is outputted as it is and when it is less than the threshold value, the coefficient is turned to zero and outputted. The output of the means 104 is outputted to a terminal 106 after receiving Haffman encoding at a variable length encoding means 105. Thus, since the coefficient at the low level is turned to zero, the generated code amount can be reduced without enlarging the quantizing step size.</p> |
