摘要 |
Correlation value calculation is carried out while a pair of window ranges being shifted using uncorrected AF data, and a pair of window ranges providing the highest correlation value is determined. Then, the difference between the smallest values in the respective window ranges is evaluated. If it is determined that the distance is large, the AF data is corrected so that the smallest values in the respective window ranges are consistent with each other, and the corrected AF data is used to carry out correlation value recalculation. Then, if the highest correlation value after correction is smaller than the highest correlation value before correction, the result of correlation value calculation after correction is employed. |