| US 7,515,736 B2 | ||
| System for road sign sheeting classification | ||
| James E. Retterath, Excelsior, Minn. (US); and Robert A. Laumeyer, Minneapolis, Minn. (US) | ||
| Assigned to Facet Technology, Corp., Eden Prairie, Minn. (US) | ||
| Filed on Feb. 11, 2005, as Appl. No. 11/56,926. | ||
| Application 11/056926 is a continuation of application No. 09/928218, filed on Aug. 10, 2001, granted, now 6,891,960. | ||
| Claims priority of provisional application 60/224761, filed on Aug. 12, 2000. | ||
| Claims priority of provisional application 60/296596, filed on Jun. 07, 2001. | ||
| Prior Publication US 2005/0249378 A1, Nov. 10, 2005 | ||
| Int. Cl. G06K 9/00 (2006.01) | ||
| U.S. Cl. 382—103 | 14 Claims |
| 1. A method for determining sheeting type of a reflective sheeting material covering at least a portion of a surface of a
road sign comprising:
using a light source to illuminate at least a portion of the reflective sheeting material covering the road sign as the light
source is traversed along the roadway;
collecting a plurality of light intensity measurements reflected from the at least a portion of the reflective sheeting material
to generate an as-measured retroreflectivity profile, the light intensity measurements corresponding to exemplary angular
displacements of incident light from a reference position; and
determining sheeting type of the reflective sheeting material based on the as-measured retroreflectivity profile.
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