A method and apparatus for identifying 3-D coordinates of a target region
on a tire includes: taking a digital image of a tire; finding an edge of
a tire bead using pixel brightness values from the tire image;
calculating tire bead circle center and radius using a plurality of image
pixels on the tire bead edge; and performing a pixel brightness search
around the bead circumference using the bead circle's center and radius
to identify the target area X, Y coordinates. The Z-coordinate and slope
of the target area are determined from multiple point distance
calculations across the region.