| 摘要 |
A method and apparatus for calibrating sensor means such as cameras and for measuring the dimension of an article using the calibrated sensor means in which a calibration frame (20) having reference points (22-40) is located in the field of view of the sensor means. Calibration constants are derived from the reference points as perceived by the sensor means having regard to known displacements. The calibration constants are used in equations which give the dimensions of the article in a subsequent measurement step taking into account perspective distortions due to the positional relationship between the sensor means and the calibration frame. In the case of elongate articles information from the sensor means is used to determine if the article is at an angle to a predetermined axis, this information being utilized in determining the dimensions of the article. |
