METHOD FOR PROCESSING A DIGITAL IMAGE OF THE SURFACE OF A TIRE IN ORDER TO DETECT AN ANOMALY

摘要

The invention relates to a method for analysing the three-dimensional digital image of the surface of a tire to be inspected in which the image is captured of the three-dimensional elevations of said surface while assigning each point of the surface represented by a pixel of the image a grey level proportional to its elevation relative to said surface, characterized in that: - from that image of the elevations, an image is formed of the orientation of the elevation gradients of the surface in which each point is assigned a grey level value proportional to the angle formed with a direction given by the projection in the plane of the image of a non-zero norm vector substantially corresponding, at that point, to the gradient vector tangent to the surface and oriented in the direction of the steepest slope. - a filtered image of the orientations is determined by converting the image of the orientation of the elevation gradients using a digital filter able to select the zones including structures similar to the reference image of the orientation of the elevation gradients with the steepest slope of a blister.