| 摘要 |
PURPOSE:To extract edge lines in a body with high accuracy by finding the turning point of a light section line on an objective body as an image and obtaining two points at which brightness on the inner periphery of a circle set around the point changes abruptly. CONSTITUTION:An object 9 is illuminated from one direction by a light source for illumination 3. When slit light is projected on the object 9 from a slit light source, a light section line 6 is formed on the object 9 in the state of crossing a ridge line 8. The light section line 6 is observed on a TV monitor 5 in the state refracted at 0 point on the ridge line 8 unless the optical axis of the lens of a camera 2 is included in the slit plane. After finding the position of the O point on the image, a circle making the O point the center is set on the image. The brightness of the circle 7 on the circumference is sampled minute ly to some degree. By differentiating the distribution of brightness and finding the absolute value, differentiated distribution of brightness is obtained. Large peaks are obtained at positions A, B angle theta of which is deviated by 180 deg., and an equation of a straight line that passes A, O, B is obtained.
|
