Patent ID: 7395966

Claim:
Apparatus for identifying objects, comprising: a multiplicity of tags, each such tag being adapted to be fixed to a respective one of the objects and comprising: at least one optical emitter, which is adapted to emit optical radiation of a respective color, selected from among a first plurality of colors emittable by the tags; and a controller, which is coupled to drive the at least one optical emitter to emit the optical radiation during a respective time slot, selected from among a second plurality of time slots during which the tags may emit the optical radiation; at least one camera, which is adapted to capture a sequence of electronic images of an area containing the objects to which the tags are fixed; and an image processor, which is adapted to process the electronic images in the sequence in order to identify, responsively to the colors of the optical radiation emitted by the tags and the time slots in which the optical radiation is emitted, the objects to which the tags are fixed.