Abstract: An encoder is arranged to add a binary code bit to block of a signal by selecting, within the block, (i) a reference frequency within the predetermined signal bandwidth, (ii) a first code frequency having a first predetermined offset from the reference frequency, and (iii) a second code frequency having a second predetermined offset from the reference frequency. The spectral amplitude of the signal at the first code frequency is increased so as to render the spectral amplitude at the first code frequency a maximum in its neighborhood of frequencies and is decreased at the second code frequency so as to render the spectral amplitude at the second code frequency a minimum in its neighborhood of frequencies.

Abstract: An apparatus identifies a program selected for reception on a monitored receiver. The monitored receiver has a receiver output, and the selected program is one of a plurality of receivable programs. The apparatus includes a tuner and demodulator arranged to receive a predetermined one of the programs. A first feature extractor extracts a first set of characteristic features from the receiver output. A second feature extractor extracts a second set of characteristic features from the predetermined program. A comparator compares the first and the second sets of characteristic features. A code extractor extracts a program identifying code from the predetermined program if the first and the second sets of characteristic features match.

Abstract: An encoder transforms at least a portion of a signal, counts the resulting transform coefficients having a zero value, and encodes the signal with the zero count. A decoder decodes the signal in order to recover the zero count. The decoder may also determine its own zero count of the signal as received and may compare the zero count that it determines to the recovered zero count. The decoder may be arranged to detect compression/decompression based upon results from the comparison, and/or the decoder may be arranged to prevent use of a device based upon results from the comparison.

Abstract: A system identifies which of first and second signal sources is supplying a program signal to a monitored receiver. The first and second signal sources and the monitored receiver are located in a household. The system extracts a reference program signature representative of an output of the monitored receiver and first and second source program signatures representative of an output of the first and second signal sources. The system identifies which of the first and second signal sources is a source of the program signal in response to the reference program signature and the first and second source program signatures.

Abstract: An audience measurement system identifies a program which is broadcast from a signal source and to which a receiver is tuned. The audience measurement system includes a code reader for reading an ancillary code of the program to which the receiver is tuned, a channel status detector for determining channel status relating to channels to which the receiver is tuned, a memory for storing ancillary codes read by the code reading means and for storing channel status determined by the channel status determining means if ancillary codes are not readable by the code reading means, and a communicator for communicating the ancillary code and/or the channel status to a central office computer.

Abstract: A system identifies which of first and second signal sources is supplying a program signal to a monitored receiver. The first and second signal sources and the monitored receiver are located in a household. The system extracts a reference program signature representative of an output of the monitored receiver and first and second source program signatures representative of an output of the first and second signal sources. The system identifies which of the first and second signal sources is a source of the program signal in response to the reference program signature and the first and second source program signatures.

Abstract: An audience measurement system identifies a program which is broadcast from a signal source and to which a receiver is tuned. The audience measurement system includes a code reader for reading an ancillary code of the program to which the receiver is tuned, a channel status detector for determining channel status relating to channels to which the receiver is tuned, a memory for storing ancillary codes read by the code reading means and for storing channel status determined by the channel status determining means if ancillary codes are not readable by the code reading means, and a communicator for communicating the ancillary code and/or the channel status to a central office computer.

Abstract: An encoder is arranged to add a binary code bit to block of a signal by selecting, within the block, (i) a reference frequency within the predetermined signal bandwidth, (ii) a first code frequency having a first predetermined offset from the reference frequency, and (iii) a second code frequency having a second predetermined offset from the reference frequency. The spectral amplitude of the signal at the first code frequency is increased so as to render the spectral amplitude at the first code frequency a maximum in its neighborhood of frequencies and is decreased at the second code frequency so as to render the spectral amplitude at the second code frequency a minimum in its neighborhood of frequencies.

Abstract: An encoder adds a binary code bit to a block of a signal by selecting a reference frequency within a predetermined bandwidth, a first code frequency having a first predetermined offset from the reference frequency, and a second code frequency having a second predetermined offset from the reference frequency. The spectral amplitude of the signal at the first code frequency is increased to render it a maximum in its neighborhood of frequencies, and the spectral amplitude of the signal at the second code frequency is decreased to render it a minimum in its neighborhood of frequencies. Alternatively, the phase of the portion of the signal at one of the first and second code frequencies whose spectral amplitude is smaller may be modified so as to differ from the phase of the reference signal component within a predetermined amount. A decoder decodes the binary bit.

Abstract: A panel arrangement is provided to collect access information relating to access by a plurality of panel members of a plurality of web sites. Each of the panel members accesses a corresponding web page stored at a central facility. The web page contains a URL for each of the web sites and an ID uniquely identifying the corresponding panel member. Each panel member transmits, either to each of the web sites corresponding to the URLs of the web page or to the central facility, the ID of the corresponding panel member and any panel member cookies which are stored by the panel member and which correspond to each of at least some of the URLs. Each of the web sites transmits, to the central facility, web site only that access information which relates to the panel members.

Abstract: A non-invasive or minimally invasive intermediate frequency (I.F.) probe is disclosed for use as part of a broadcast audience measurement system. The probe can be used both to acquire a representation of a tuned signal and to inject a recognition signal into a tuned signal. The probe is configurable for use with both analog (e.g., NTSC, PAL or SECAM) and digital (e.g., ATSC) television broadcasts. Optionally, when in the injection mode, the I.F. probe can be used with another sensor;to determine which of several inputs to a monitored receiver is providing the audio and/or video output(s) selected by an audience member.

Abstract: A system determines an operating mode of a recording/playing device. The device generates a recording indicating signal during recording and operates in conjunction with a receiver. The system includes a tuning means for tuning to a program signal; four signal acquiring means for acquiring four signals; and determining means coupled to all four signal acquiring means for determining an operating mode of the device, based on the four acquired signals. The first of the four signals is acquired from an output of the device. The second signal is acquired from an output of the tuner. The third signal is acquired from an output of the receiver. The fourth signal is the recording indicating signal.

Abstract: A checksum is extracted from an image downloaded to a content recipient. The content recipient transmits the extracted checksum to a data collection site. The data collection site compares the received checksum to a reference checksum. If the received checksum and the reference checksum match, the data collection site uses an image corresponding to the reference checksum as the downloaded image. If the received checksum and the reference checksum do not match, the data collection site retrieves the down-loaded image from the content recipient.

Abstract: An encoder is arranged to add a binary code bit to a block of a signal by selecting, within the block, (i) a reference frequency within the pretermined signal bandwidth, (ii) a first code frequency having a first predetermined offset from the reference frequency, and (iii) a second code frequency having a second predetermined offset from the reference frequency. The spectral amplitude at each of the first and second code frequencies may be respectively modified to be a maximum in a first neighborhood of frequencies extending about the first code frequency and a minimum in a second neighborhood of frequencies extending about the second code frequency. Alternatively, the phase of a signal component at one of the first and second code frequencies may be changed relative to a reference signal component.

Abstract: An audience measurement system for a receiver comprises monitoring equipment, such as a decoder, ON/OFF detector and transmitter, coupled to the receiver. The decoder reads program codes embedded in a program received by the receiver. The system also comprises a base unit and a mobile unit, such as a telephone handset. The handset receives the program codes transmitted from the decoder and prompts (via a visual display or audio tone) an audience member to enter personal data (i.e. who the audience member is) via a keypad or voice input. The program data (from the decoder) and personal data (input by the audience member) is provided to the base unit, where it is time stamped and stored. The base unit includes telephone circuitry to transmit the stored data to a data collection central facility via a public switched telephone network.

Abstract: A client information discovery arrangement is provided to discover client information relating to access by the clients of a plurality of web sites. Each of the clients accesses a corresponding web page stored at a central facility. The web page contains a URL for each of the web sites and an ID uniquely identifying the corresponding client. Each client transmits, either to each of the web sites corresponding to the URLs of the web page or to the central facility, the ID of the corresponding client and the client information which are stored by the client and which correspond to each of at least some of the URLs. The client information may include cookies.

Abstract: Each of a plurality of advertising meters operates on a computer at a corresponding statistically selected site. Each advertising meter is arranged to detect tags from click-through URLs in advertising banners contained in messages communicated to the computer from remote content suppliers over a communication link. Each advertising meter is also arranged to communicate the tags to a remote central facility for use in assembling reports.

Abstract: Web content received by a computer is processed such that a reference to a control is inserted in HTML received by the computer and the control is executed in response to the reference in order to process the web content in the received HTML. The control interfaces with a meta-level of program code, such as a browser, in order to process the web content. The control, for example, may be executed in order to meter exposure of an object, such as an advertising image object.

Abstract: A television audience measurement system measures viewing of a television program viewed on digital television located in a statistically selected site by (i) retrieving an audience measurement data packet from a television set in order to identify the television program, (ii) detecting an audio code embedded in the television program in order to identify the television program, (iii) extracting an audio signature from the television program in order to identify the television program, (iv) identifying the television program through use of a software agent, and (v) selecting at least one of the retrieving means, the detecting means, the extracting means, and the software agent in order to identify the television program.

Abstract: An encoder is arranged to add a binary code bit to a block of a signal by selecting, within the block, (i) a reference frequency within the predetermined signal bandwidth, (ii) a first code frequency having a first predetermined offset from the reference frequency, and (iii) a second code frequency having a second predetermined offset from the reference frequency. The spectral amplitude at each of the first and second code frequencies may be respectively modified to be a maximum in a first neighborhood of frequencies extending about the first code frequency and a minimum in a second neighborhood of frequencies extending about the second code frequency. Alternatively, the phase of a signal component at one of the first and second code frequencies may be changed relative to a reference signal component.