ALEXANDRIA, Va., Jan. 13 -- United States Patent no. 12,525,991, issued on Jan. 13, was assigned to Digimarc Corp. (Beaverton, Ore.).
"Sparse path codes and methods" was invented by Brett A. Bradley (Portland, Ore.), Nicholas Anderson (Colorado Springs, Colo.) and William Y. Conwell (Portland, Ore.).
According to the abstract* released by the U.S. Patent & Trademark Office: "A series of marks and absences of marks (voids) arrayed along one or a few mathematically-defined paths, define a message-conveying sparse path code. Multiple improvements in the forms of such codes, and related encoding and reading techniques, are detailed. Some such improvements provide greatly increased robustness and decreased visibility. A variety of other featur...