| 摘要 |
PURPOSE:To accurately evaluate the interval between two images even if the illuminance distributions of 1st and 2nd images are asymmetrical by performing correlative arithmetic as to a group of the centers of gravity of function values based upon the quantities of light found as to plural partial element train which photodetect the 1st and 2nd images. CONSTITUTION:Data G3-Gn-2 indicating the centers of gravity of the function values based upon the quantities of light are generated as to a small number of picture element signals D1-D5, D2-D6, D3-D7...Dn-4-Dn among (n) picture element signals D1-Dn. Then the data of the picture element signals D1-Dn are converted into data on light quantity gravity center groups G3-Gn-2. This data conversion is performed as to a standard part and a reference part respectively. Therefore, when the degree of correlation among the gravity center groups G2(3+s)-G2(n-2+a) of the standard part is maximum, the intervals between the gravity center groups G13-G1(n-2) of the standard part and the gravity center groups G2(3+s)- G2(n-2+s) of the reference part at a scanning positions (s) are detected as the interval between the two images. Consequently, the image interval can correctly be evaluated without being affected by the illuminance distributions. |
