Patent ID: 7120286

Claim:
A method for operating a vision system, comprising: determining a set of coordinates for a plurality of edge points along an edge contour of an object, wherein the plurality of edge points extend over a depth range greater than the depth of field of an image of the edge contour, and wherein determining the set of coordinates comprises: (a) determining the XYZ coordinates for at least a latest previous edge point in at least a latest previous edge point source image; (b) automatically determining a next edge point XY trial location based at least partially on the XY location of the latest previous edge point; (c) determining a next edge point source image that is focused at a different Z coordinate than the latest previous edge point source image, including at least one of: (i) evaluating a focus characterization in the vicinity of the next edge point XY trial location for a plurality of previously acquired images corresponding to a plurality of focus positions, (ii) estimating a Z coordinate of the next edge point in the vicinity of the next edge point XY trial location based on previously acquired data, (iii) estimating a focus position corresponding to a well focused image of the next edge point in the vicinity of the next edge point XY trial location based on previously acquired data, and (iv) acquiring a plurality of images that include the next edge point XY trial location and that correspond to a plurality of focus positions over a range that includes a focus position corresponding to the Z coordinate of the latest previous edge point; and (d) searching for the next edge point in the next edge point source image.