Method and apparatus for identifying three dimensional coordinates on a tire

An apparatus for determining coordinates of a target region in a tire comprising:

• means for generating a tire digital image;
• means for finding the edge of a tire bead from the tire image using pixel brightness values from the tire image;
• means for calculating a tire bead circle center and radius using a plurality of image pixels on the tire bead edge;
• and
• means for performing a pixel brightness search around the bead circumference using the bead circle's center and radius to identify by pixel brightness differentiation the target region X, Y coordinates on the tire;
• wherein the means determining the slope of the target area comprises:
• a distance-measuring device locatable at a first position (P1) above the target region using X, Y coordinates of the target region;
• the distance-measuring device measuring the distance D1 from the distance-measuring means to a first location (P1) in the target region;
• the distance-measuring device being locatable to a second position above a second location (P2) in the target region along a line through the bead circle center and measuring the distance (D2) from the distance measuring device (P2), the target region slope with respect to horizontal being derived from the distances (D1) and (D2) at positions (P1 and P2).