| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for setting a processing region at high speed in sharing interference measurement. SOLUTION: Light emitted from a lens is diffracted and allowed to interfere, to thereby acquire a sharing interference image. Then, the phase of diffracted light is changed, and plural image data (the coordinate, the strength) having the strength changing in time by the phase change are taken into a storage device. The magnitude of the change of strength data (strength changing quantity) in each pixel is calculated in the plural image data. The region of the image data is divided into four small regions by a line segment parallel to a sharing axis through the approximate center of the image data region and a line segment perpendicular to the sharing axis. Plural lines perpendicular to the sharing axis are provided in each small region, and the sum of the strength changing quantity of each pixel on each line is acquired, and a line on which the sum of the strength changing quantity becomes maximum is determined. Finally, an edge on which the intensity change becomes not less than a threshold is determined on the line on which the sum of the strength changing quantity becomes maximum in each small region. |
