| 摘要 |
<p>The direction and magnitude of the level gradient of a gray-scale image are found for each pixel. A line segment with a predetermined length is drawn from a pixel whose magnitude of the level gradient is over a predetermined value or from a point spaced by a predetermined distance from the pixel. The brightness level of the line segment is made to correspond to the magnitude of the level gradient. Portions where many line segments cross each other or many line segments are densely present are detected, and the center, angle, and so forth of an object appearing on the image are recognized.</p> |
