Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

Koninklijke Phillips Electronics N.v.

Koninklijkle Philips N.v.

Philips Lighting Holding B.v.

Intrinsic Id B.v.

Koninklijke Philips Electronics N.v.

Johan P M G Linnartz

Johan Cornelis Talstra

Gijsbert Joseph Van Den Enden

Johannes H M Spruit

Maurice J J J-b Maes

Paulus H A Damink

Geert F G Depovere

Lorenzo Feri

Ronald Rietman

Dragan Sekulovski

Hongming Yang

Antonius A C M Kalker

Jaap Andre Haitsma

Sel Brian Colak

Marten Erik Van Dijk

Franciscus L A J Kamperman

Nicolas Bailleul

Johannes Petrus Wernars

Nebojsa Fisekovic

Ludovicus M G M Tolhuizen

Jorge Guajardo Merchan

Trevor G R Hall

Peter M J Rongen

Tim C W Schenk

Stephanus J J Nijssen

Luca Giangaspero

Maurice H J Draaijer

Hendricus T G M Penning De Vries

Johan C Talatra

Emmanuel D L M Frimout

Erwin Kragt

Sel B Colak

Christianus W F Vriens

Evgeny A Verbitskiy

Theodorus J J Denteneer

Xiangyu Wang

Paulus J G Vranken

Wijnand J Rietman

Andries P Hekstra

Constant P M J Baggen

Johannes P Wernars

Klaas Vegter

Sel-Brian Colak

A method for driving a lamp () comprises the steps of: generating a lamp current (I) having a constant magnitude; defining a commutation period having a duration T; defining a time base of original commutation moments, having fixed mutual intervals of 0.5*T; receiving data to be embedded in the light output; commutating the lamp current at commutation moments; wherein individual commutations are time-modulated in order to encode said received data. Preferably, a commutation moment is: either equal to an original commutation moment if there are no data to embed; or advanced over a modulation distance (&#x394;) with respect to the corresponding original commutation moment in order to encode data having a first value ('0'); or delayed over said modulation distance (&#x394;) with respect to the corresponding original commutation moment in order to encode data having a second value ('1').

Method and device for driving a lamp

A record carrier has substantially parallel tracks having first variations of a first physical parameter and second variations of a second physical parameter of the track. The first variations represent information recorded on the record carrier, this information being recoverable by a controllable type of data processing. A modulation pattern of the second variations represents a code for controlling the type of data processing. In respect of a code track that includes the modulation pattern, the modulation pattern in the left neighboring track is aligned to the modulation pattern in the right neighboring track. Thereby crosstalk due to the second variations is decreased, and at least two tracks have the same modulation pattern. The playback device has a demodulator () and a control unit () for retrieving the code from at least two tracks.

Record carrier, playback device and method of recording information

Methods for exchanging signals via a network with nodes (-) improve the performance of the network by letting a destination node () s receive the signals originating from a source node () via different first and second signal routes, and by processing and correlating these signals in the destination node (). In dependence of a correlation result, a process for processing a signal in a node (-) is adjusted. This process may be situated in the destination node (), or in the source node () or an io intermediate node (-), in which case a control signal is to be exchanged. A learning algorithm for the adjusting of the process can be run in the nodes (-). Label switched routing can be introduced, whereby the label signal is sent from the source node () to the destination node via a third signal route different from the first and second signal route, to improve the efficiency of the nodes (-).

Wireless multi-path transmission system (MIMO) with controlled repeaters in each signal path

The invention relates to a method of copy-protection of information stored on an information carrying medium. The method allows a reading device (e.g. a DVD drive) and an application device (e.g. an MPEG decoder) to exchange copy-protection information regarding the information carrying medium (e.g. an optical record carrier like a CD or DVD) and the content on that medium. The method is cryptographically secure, taking into account the situation where reading device and application device are connected to an open bus in a personal computer. In view of the high-volume nature of the drive, the method can be implemented cheaply. The inventive method is robust against a so-called man-in-the-middle attack. The invention relates also to a method of exchanging copy-protection information, to a copy-protection system and to devices for carrying out these methods, in particular a reading device, an application device and a device for playback and/or recording of information.

Method and system of copy protection of information

An MPEG video stream generator, which contains several slightly different programs, each with approximately the same content. The MPEG stream is constructed in such a manner that a simple transcoder can effectively select one of the programs. This is achieved by storing the differences relative to the default program in selected user data fields. The transcoder is little more than an MPEG bitstream parser, which replaces the bits corresponding to selected set of macroblocks by the replacement data stored in the user data fields. A standard MPEG decoder without any knowledge of the embedded user data fields will simply extracted the default program. One application relates to broadcasting of a television program with or without a logo, or a commercial with or without a public warning. Another application relates to copy-protection schemes. In such a scheme, the default program contains a ticket indicating that the contents may be copied once. Upon recording, this ticket is removed and replaced by the content accommodated in the user data field.

Video signal transmission

A system for copy protection of recorded information is disclosed, including an information carrier, a recorder and a player. The information carrier, e.g. an optical disc, includes a medium mark representing a first bitpattern, which medium mark cannot be copied on standard recording devices. The recorded information includes a watermark representing a second bitpattern, which second bitpattern has a predefined relationship to the first bitpattern. The watermark cannot be manipulated without disturbing the quality of the reproduction of the information. The relationship, preferably a one-way function, between the watermark and the medium mark requires that an illegal copy also has the corresponding medium mark. As neither the watermark nor the medium mark can be manipulated, a strong protection against illegal copying is achieved. The recorder includes encoder means for embedding the watermark in the information and generator means for generating the second bitpattern according to said relationship. The player includes verification means for verifying said relationship.

Recording information with a watermark related to a prerecorded medium mark on an information carrier

A method and an arrangement for detecting a multi-bit watermark in a signal (e.g. a video image) are disclosed. Each bit of the multi-bit value is represented by an embedded watermark subpattern in the signal. Instead of detecting in a conventional manner the presence of each individual subpattern (i.e. detecting each individual bit), the detection comprises the steps of: detecting () the presence of the full watermark in the signal irrespective of its multi-bit value, and detecting () to which extent the presence of subpatterns corresponds with the multi-bit value to be checked. The reliability of watermark detection is hereby improved.

Watermarking an information signal

An MPEG-encoded video signal includes groups of pictures (GOPs), each GOP having an intraframe coded (I) picture and a series of predictively encoded (P) pictures and bidirectionally predictively encoded (B) pictures. Usually, the GOP structure IBBPBBP . . . is used. However, in order to embed a watermark in the MPEG-encoded video signal, the MPEG encoder is forced to produce a GOP structure which does not normally occur, e.g., a GOP including a BPP sequence. Different symbol values can be assigned to different positions of the BPP sequence in the GOP.

Embedding supplemental data in a digital video signal

A method and an arrangement for detecting a multi-bit watermark in a signal (e.g. a video image) are disclosed. Each bit of the multi-bit value is represented by an embedded watermark subpattern in the signal. Instead of detecting in a conventional manner the presence of each individual subpattern (i.e. detecting each individual bit), the detection comprises the steps of: detecting ( ) the presence of the full watermark in the signal irrespective of its multi-bit value, and detecting ( ) to which extent the presence of subpatterns corresponds with the multi-bit value to be checked. The reliability of watermark detection is hereby improved.

Supplemental data is embedded in an information signal such as a sigma-delta modulated audio signal. The encoded signal includes two or more channels, e.g. a left channel bit stream and a right channel bit stream. The same supplemental data is accommodated at corresponding predetermined bit positions, e.g. every Mth bit position, of the bit streams. This allows detection and extraction of the supplemental data without the need for accommodating a sync pattern in the signal. At the receiving end, a sequence of Mth bits from the first channel is compared with a corresponding sequence of Mth bits from the second channel. If they are identical, the sequence is a candidate supplemental data sequence. This is done for different sequence positions until the supplemental data has been found.

Embedding and extracting supplemental data in an information signal

A multi-bit watermark is detected in a signal (e.g. a video image) in which each bit of the multi-bit value is represented by an embedded watermark subpattern in the signal. The watermark is detected by first detecting the presence of the full watermark in the signal irrespective of its multi-bit value, and then detecting to which extent the presence of subpatterns corresponds with the multi-bit value to be checked.

Watermarking an informational signal

A record carrier has substantially parallel tracks, which exhibit first variations of a first physical parameter and second variations of a second physical parameter of the track. The first variations represent information recorded on the record carrier, which information is recoverable by means of a controllable type of data processing. A modulation pattern of the second variations represents a code for controlling the type of data processing. With respect to a code track that includes the modulation pattern, the modulation pattern in the left neighboring track is aligned to the modulation pattern in the right neighboring track. Thereby crosstalk due to the second variations in decreased, and at least two tracks have the same modulation pattern. The playback device has a demodulator and a control unit for retrieving the code from at least two tracks.

A method and arrangement for detecting a watermark in an information signal. The method may include the steps of computing the correlation (d ) of the watermark (W ) and the information signal (e.g. an image Q) for a plurality of positions (k) of the watermark with respect to the information signal, and detecting whether at least one of the respective correlation values exceeds a given threshold. The step of detecting may include determining the standard deviation (&sgr; ) of the respective correlation values (d ), and setting the threshold to a given multiple (T) of the standard deviation. The multiple (T) is derived form a desired false alarm rate (watermark detected when there is none, or no watermark detected when there is one).

Watermark detection

Recent copy-protection schemes for digital video copy-protection rely on a pixel-watermark together with the presence of a 'ticket' to implement the 'copy-once' state of content. This ticket is designed to entitle the owner of a disk/tape to making one copy of digital content. We disclose a method to pass along this ticket with the video signal after content has been converted to the analog domain. This form of the ticket is called the analog ticket. The analog signal may be recorded on a legacy device that does not comply with the copy-protection scheme (e.g. ordinary VCRs). The analog ticket is designed such that it is automatically removed in these legacy devices. Next generation copies by compliant devices are made impossible. Three possible ways of embedding the ticket signal into the analog video signal are proposed.

Copy protection schemes for copy protected digital material

Growing community of inventors

Eindhoven, Netherlands

Johan P M G Linnartz