The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 02, 2006
Filed:
Aug. 14, 2001
Willem Marie Julia Marcel Coene, Eindhoven, NL;
Johan Cornelis Talstra, Eindhoven, NL;
Antonius Adriaan Maria Staring, Eindhoven, NL;
Jacobus Petrus Josephus Heemskerk, Eindhoven, NL;
Willem Marie Julia Marcel Coene, Eindhoven, NL;
Johan Cornelis Talstra, Eindhoven, NL;
Antonius Adriaan Maria Staring, Eindhoven, NL;
Jacobus Petrus Josephus Heemskerk, Eindhoven, NL;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
A method and device for adding or extracting a secondary information signal to/from a runlength-limited code sequence, includes detecting a polarity of a runlength at a first predetermined position of the runlength-limited code sequence and setting a parameter reflecting the degree of freedom that is present in the runlength-limited channel code, e.g., the selection of a merging bit pattern in the CD-standard, on the basis of the detected polarity so as to obtain a predetermined polarity of a runlength at a subsequent second predetermined position of the runlength-limited code sequence. The predetermined polarity then corresponds to a binary value of the secondary information. Thus, a side-channel with a small capacity is provided, which is positioned very close to the physical channel such that the secondary information is hard to be detected from the EFM bit stream. Therefore, the side-channel can be used as a hidden channel for copy protection purposes.