| 摘要 |
PROBLEM TO BE SOLVED: To well extract the characteristics of an original waveform before re-sampling by suppressing not only the lowering of brightness generated by point sampling but also the lowering of resolving power generated by max. value sampling. SOLUTION: The original signal data row inputted from an A/D converter 2 is scanned by a window. A max. value selecting circuit 6 and a min. value selecting circuit 8 output the max. and min. values of the data value in the window. On the basis of the code of the difference between adjacent data calculated by a subtractor 12, an inflaction point detecting circuit 18 detects the inflection point of the data value. When the inflection point detecting circuit 18 detects the max. and min. values, the max. and min. values from the max. value selecting circuit 6 and the min. value selecting circuit 8 are outputted to an intermediate signal data row. In a case other than this, the data value in the window at a predetermined position is outputted to the intermediate signal data row. The intermediate signal data row is re-sampled at a constant interval to obtain a sampling result wherein the max. and min. values are necessarily caught. |
