摘要:
methods of embedding and detecting a watermark in an information signal (x(n), y′(n)) which are robust against sampling rate conversions of the watermarked signal (y(n)) adapts frame lengths used by an embedder and the detector, respectively, so as to preserve a constant ratio between the respective sampling rate and frame length. The frame lengths may be calculated from a greatest common divisor of a set of sampling rates providing watermarks which are robust against sampling rate conversions between any sampling rates of the set of sampling rates.
摘要:
Disclosed is a method of adjusting a supplementary data signal (wm(n)) to be embedded in an information signal (x(n)), for example an audio signal. The method comprises the steps of determining (301) a position where a predetermined property of the information signal exceeds a predetermined threshold, e.g. an attack position, and suppressing (302) the supplementary data signal in a predetermined neighbourhood of the determined position.
摘要:
The invention relates to a method of checking the correct operation of a signal transformation wherein a input signal is transformed into an output signal. The method comprises: deriving a first robust feature from the input signal; deriving a second robust feature from the output signal; comparing said first and second robust features; in case of sufficient sumilarity, concluding a correct operation of said signal transformation, and in case of insufficient sumilarity, concluding a false operation of said signal transformation. In a special embodiment, the method is applied wherein the first robust feature is embedded in the input signal through watermark technology, the thus obtained signal being transmitted to a receiver so as to retrieve an output signal corresponding to said input signal.
摘要:
A multirate filter according to the invention comprises, a) an input unit (10) for receiving an input signal (Sin) and for providing a plurality of intermediate signals (IS1, IS2) in response to said input signal, b) a filter unit (20) coupled to the input unit (10), and c) an output unit (30) coupled to the filter unit (20), for generating an output signal (Sout). The filter unit (20) comprises at least a first and a second filter module (21, 22), with a transfer function H0(z) and a transfer function H1(z) respectively, which are mutually related according to the relations H0(z)=c0(HB(z)+Mα,ψHB(z)) and, H1(z)=c1(HB(z)+Mα,ψHB(z)) wherein, Mα,ψ(HB(z))=αz−2ψHB*(z−1), and wherein Formula (I), being the z-transform of hb[m]. The multirate filter comprises a combination unit (11) coupled to said filter modules (21, 22) for generating a first combination signal (Ssum) and a second combination signal (Sdiff).
摘要:
The invention provides a method for authenticating a physical object (OBJ) using a first helper data (W1) and a first control value (V1) associated with a reference object. The method comprises a step to generate a first property set (S1) using a noise compensating mapping (NCM) on information derived from the first helper data (W1) and a metric data (Y) associated with the physical object, and a step to establish a sufficient match between the physical object and the reference object using the first property set (S1) and the first control value (V1). The method further comprises a step to generate an update data (WUPD) for updating the first helper data (W1) using the first helper data (W1), the first property set (S1) and the metric data (Y). Also provided is a client terminal configured to carry out the method.
摘要:
A relative movement sensor for measuring movement of an object (15) and the sensor relative to each other, the sensor comprising a plurality of lasers (3,5) for generating respective measuring beams and illuminating the object (15) therewith, and a plurality of respective photodiodes (4,6) for measuring changes in operation of each laser cavity caused by reflected measuring beam radiation re-entering the respective laser cavity and the optical wave in the laser cavity. The plurality of lasers (3,5) are operated in a time-multiplexed manner such that only a subset (i.e. one or more) of the lasers is operated at any one time, the remaining lasers being idle. This reduces peak power dissipation and prevents erroneous interference caused by measuring beam radiation from one laser entering the cavity of another laser.
摘要:
The invention relates to a method of authentication of a physical object and an apparatus applying said method. The method uses a helper data (W1) and a control value (V1) associated with a reference object to generate a first property set (C1) using the helper data (W1) and a metric (Y) associated with the physical object. It further comprises a step to generate a second property set (S1) using a noise compensating mapping (NCM) on the first property set (C1), as well as a step to establish a sufficient match between the physical object and the reference object using the second property set (S1) and the first control value (V1). The method is characterized by a step that generates an error measure (ERR) by quantifying the noise removed by the noise compensating mapping (NCM) using the first property set (C1) and information derived from the noise compensating mapping (NCM). Error measure (ERR) is subsequently used for generating an authentication decision (D). Also provided is an apparatus configured to carry out the method.
摘要:
System for performing telemetric measurements, comprising a plurality of mobile communication devices (100), each communication device (100) being provided with at least one sensor (110) and a sensor control section (120) for performing measurements, a cellular communication network structure for the mobile communication devices, a server provided with communication means for receiving measurement data from the plurality of mobile communication devices (100), and for sending measurement instructions to respective sensor control sections (120) of the mobile communication devices (100) wherein the sensor control sections (120) are programmable by the server.
摘要:
The invention relates to a method of authentication of a physical object and an apparatus applying said method. The method uses a helper data (W1) and a control value (V1) associated with a reference object to generate a first property set (C1) using the helper data (W1) and a metric (Y) associated with the physical object. It further comprises a step to generate a second property set (S1) using a noise compensating mapping (NCM) on the first property set (C1), as well as a step to establish a sufficient match between the physical object and the reference object using the second property set (S1) and the first control value (V1). The method is characterized by a step that generates an error measure (ERR) by quantifying the noise removed by the noise compensating mapping (NCM) using the first property set (C1) and information derived from the noise compensating mapping (NCM). Error measure (ERR) is subsequently used for generating an authentication decision (D). Also provided is an apparatus configured to carry out the method.
摘要:
The invention provides a method for authenticating a physical object (OBJ) using a first helper data (W1) and a first control value (V1) associated with a reference object. The method comprises a step to generate a first property set (S1) using a noise compensating mapping (NCM) on information derived from the first helper data (W1) and a metric data (Y) associated with the physical object, and a step to establish a sufficient match between the physical object and the reference object using the first property set (S1) and the first control value (V1). The method further comprises a step to generate an update data (WUPD) for updating the first helper data (W1) using the first helper data (W1), the first property set (S1) and the metric data (Y). Also provided is a client terminal configured to carry out the method.