| 摘要 |
<p>Image processing apparatus for detecting a bounded region of an image, comprising mean (120) for scanning the image via a raster scan to produce a signal indicative of image intensity at a plurality of picture points, means (64,72) for comparing the image intensity at each of the said picture points with that of a neighbouring point in each of at least two directions to derive therefrom a difference value, means (66, 68, 74, 76) for labelling the picture points as corresponding to region boundaries whenever the difference values exceed a predetermined threshold value, means (126, 127, 128, 129) for exanding the region boundaries by labelling further picture points as region boundaries such that boundaries between neighbouring picture elements along a scan line are expanded to successive neighbouring picture elements along the said scan line and boundaries between neighbouring picture elements or neighbouring scan lines are expanded to neighbouring successive scan lines, and means (142, 144, 146) for delaying signals associated with different types of region boundanes by different amounts to superimpose those signals corresponding to picture points labelled as being included within a plurality of expanded boundaries.</p><p>The apparatus is particularly useful for detecting flaws in articles such as potatoes, or in sheet material, for example plastic laminate or sheet material</p> |
