An image processing scheme for measurement of specular weld pool surface

The authors used a low power laser to project a dot-matrix pattern onto the specular weld pool surface. The reflection of the laser was intercepted by an imaging plane. While the reflection of the laser travels without reducing much of the intensity, the intensity of the arc radiation decays with the distance rapidly and clear laser reflected image forms on imaging plane viewing by a filter-fitted camera. To compute the weld pool surface, this paper proposes an image processing scheme to extract the reflection points from the image and then match the reflection points with their projection points. The establishment of the correspondence provides the data needed to reconstruct the weld pool surface based on the reflection law.