Abstract: The bitstream includes digital codes representing an information signal. At least one digital code is selected. The code occupies a part of the bitstream which is to contain at least one watermark code which represents a watermark perceptible in the information signal. The selected digital code(s) are removed from the said part of the bitstream. The watermark code(s) are put in the said part of the bitstream in place of the selected code(s). The number of bits of the selected code(s) removed from the said part of the bitstream is greater than or equal to the number of bits of the said watermark code(s) put in the said part. The removed selected code(s) are appended to an end of the bitstream and/or placed in watermark user data fields created in the bitstream.

Abstract: An encoding data processing apparatus generates a video material item marked copy by embedding a payload data word into the video material item. The video material item includes plural video frames. A code word generator generates a water mark code word from the payload data word and reads data representing the water mark code word into a shuffle data store. A shuffle processor generates pseudo randomly at least one address within an address space of the shuffle data store for each video frame and reads data representing part or parts of the water mark code word out from the data store at locations identified by the pseudo randomly generated address. A data embedding processor receives the video material item and embeds the data representing the part or parts of the water mark code word read out from the shuffle data store for each frame into a corresponding frame of the video material item.

Abstract: A water marking system generates a water marked image frame for conveying a payload data word by combining at least one image frame with a two-dimensional water mark pattern. The water mark pattern includes plural regions each associated with one of symbols of the payload data word. Each region includes a two dimensional water mark block selected from a predetermined set of possible water mark blocks to represent the value of the payload data symbol associated with that region. A detecting data processing apparatus detects the payload data from a received water marked image frame, which has been encoded by utilizing a block match prior probability calculator operable to correlate each region of the water marked image frame with each of the water mark blocks from the set of water marked blocks) to form for each region a set of probability surfaces.

Abstract: A data processing apparatus is operable to identify one of a plurality of code words present in a watermarked version of a material item. The marked version is formed by combining each of a plurality of parts of a code word with one of a plurality of units from which the material item is comprised. The apparatus comprises a recovery processor operable to recover at least one part of the code word from a corresponding unit of the marked material item, and a correlator. The correlator is operable to generate for the marked material unit, a dependent correlation value for the part of the code word recovered from the material unit and the corresponding part of at least one of the re-generated code words from the set. A detector is operable to determine whether at least one of the code words is present in the marked material item from the dependent correlation value for the part of the code word exceeding a predetermined threshold.

Abstract: A method of detecting a version of input data content, there being a plurality of different versions of said data content, in which: said data content is arranged as two or more segments according to a segmentation pattern; and said versions of said data content are identifiable by corresponding identification data patterns by which at least some of said segments have respective identification data; said method comprising the steps of: (i) detecting said identification data in respect of said segments of said input data content; (ii) comparing said detected identification data with said identification data patterns corresponding to said different versions of said data content; and (iii) detecting that said input data content comprises at least a contribution from a certain version of said data content if a sum of matches obtained between said detected identification data and said identification data pattern for said certain version exceeds a threshold number.

Abstract: An encoding data processing apparatus is arranged to generate a marked copy of an item of material by introducing at least one code word into a copy of the material item, the code word being arranged to identify a payload data word. The encoding apparatus comprises an encryption circuit operable to receive a payload encryption key and to receive the payload data word, and to encrypt the payload data word using the payload encryption key. A pseudo random number generator receives the encrypted payload data and a finger print key and generates the code word having a plurality of code word coefficients using the encrypted payload as a seed for the pseudo random number generator and the finger print key. A combiner combines the code word with the material to form the marked copy of the material item. The encoding apparatus may form part of a media terminal for marking material items with the code words, when the material items are to be reproduced.

Abstract: An encoding data processor generates a video material item marked copy by representing a payload data word as a code word and embedding the code word into a copy of the video material item. A preprocessor divides the payload word into plural parts, forms plural initial values from the plural parts, each initial value formed by adding parts of the payload data word to each initial value successively starting with the first part added to the first initial value, and adds the first and second to the second initial value so each subsequent initial value includes all parts of the payload data word of the previous initial values and a new part of the payload data word. An encryption processor receives each initial value and generates an encrypted data stream using a payload encryption key. A combiner combines the encrypted payload data word with the video material item.

Abstract: An encoding data processing apparatus is arranged to generate a marked copy of an image by introducing a code word into a copy of the image. The apparatus comprises a code word generator operable to generate the code word. The encoding apparatus includes an image perception analyser and a strength adapter. The image perception analyser is operable to receive the image and to generate weighting factors. A combiner is operable to combine the weighted code word with the image. The image perception analyser includes a contrast masking engine, a smoothness compensation engine and a compensation combiner. The weighting factor has an effect of reducing the code word coefficients for image parts having lower relative contrast measures. A compensation combiner is operable to combine the compensation factors with the weighting factor. The likelihood of a code word being perceivable when the code word is combined with an image is reduced.

Abstract: An encoding data processing apparatus generates a video material item marked copy by embedding a payload data word into the video material item. The video material item includes plural video frames. A code word generator generates a water mark code word from the payload data word and reads data representing the water mark code word into a shuffle data store. A shuffle processor generates pseudo randomly at least one address within an address space of the shuffle data store for each video frame and reads data representing part or parts of the water mark code word out from the data store at locations identified by the pseudo randomly generated address. A data embedding processor receives the video material item and embeds the data representing the part or parts of the water mark code word read out from the shuffle data store for each frame into a corresponding frame of the video material item.

Abstract: A method includes generating, for a signal sample, first and second gaussian likelihood functions describing a likelihood of a watermark codeword coefficient value embedded into the signal sample being, respectively, positive and negative. The first gaussian likelihood function has a mean defined by a sum of a local mean value and a watermark strength value and a standard deviation defined by a local standard deviation. The second gaussian likelihood function has a mean defined by a difference between the local mean value and the watermark strength value and the standard deviation defined by the local standard deviation. The method also includes detecting a watermark in an image signal based on a probability of watermark codeword coefficients added to the signal sample being one of positive or negative, the probability being calculated from the first gaussian likelihood function and the second gaussian likelihood function.

Abstract: A data processing apparatus includes a registration processor that divides a frame of a water marked image into a plurality of image blocks. For each of the image blocks, an observed probability of possible distortion vectors representing shifts of the image block with respect to positions of the block in the original version of the image is estimated. For each of the image blocks, forward and backward probability distribution estimates of possible distortion vectors within the image block are generated recursively from the respective observed probability of distortion vectors for the image block and forward and backward probability distribution estimates determined respectively from previous and subsequent image blocks for a predetermined path through the blocks. For each image block, the forward and backward probability distribution estimates and the observed probability of distortion vector are combined to form a most likely distortion vector estimate.

Abstract: A data processing apparatus registers an image encoded with a two-dimensional water mark pattern. The water mark includes for each image frame a water mark frame pattern of water mark blocks. The water mark pattern includes plural regions each including one water mark block selected from a predetermined set of possible water mark blocks based on a key sequence. The key sequence provides a predetermined sequence of selected water mark blocks to form the water mark pattern of each frame to provide a predetermined sequence of water marked frames. The data processing apparatus includes a block match processor generating block match probabilities including for each region of a current frame of the water marked image a probability surface of possible distortion vectors for each possible water mark block of the set of possible water marked blocks that may have been added to that region of the image frame.

Abstract: According to the present invention there is provided an encoding data processing apparatus for generating a marked copy of an item of material by introducing code words into a copy of the material item. The code words are arranged to identify a data word from a set of data words having at least two fields. The apparatus comprises a code word generator operable to generate at least two code words having a plurality of code word coefficients, each of the code words being independently generated from a different code word seed, and an encoding processor operable to combine the code word coefficients with the material item. One of the code words is selected from a first set in dependence upon a value of a first of the data fields and one of the code words is selected from a second set in dependence upon a value of a second of the data fields.

Abstract: A watermarking system comprises an encoding data processor operable to generate at least one marked version of an original item of material by introducing one of a predetermined set of code words into a copy of the original material item. The encoding data processor is arranged to form other code words of the set by cyclically shifting a first code word. The system includes a detecting data processor operable to identify the code word in the marked material item. The detecting data processor is operable to recover the code word from the marked material item and to form a Fourier transform of the recovered code word and a Fourier transform of the first code word of the set. The data detecting processor forms correlation samples by forming an inverse transform of a combination of the recovered and the first code word. Each of the correlation value samples provides the correlation value for one of the set of code words.

Abstract: A recording system for applying access control processing to input data content and for recording access-controlled data content on a computer readable storage medium. The recording system includes an encryption apparatus for encrypting portions of the input data content and an access control memory device which securely stores information from which a private key of a public key/private key pair associated with a data content recording user or user group is derivable. The encryption apparatus and the access control memory device co-operate to provide access control data including content recorder access control data and default access control data. The default content access control data provides the same level of access to the input data content as the level of access available to the data content recording user/user group. A recorder is provided for recording the encrypted input data content and the content access control data on the computer readable storage medium.

Abstract: A system for watermarking and distributing material includes a data processing apparatus, which operates as a watermark encoder. The data processing apparatus is operable to process an original material item to form a reduced-bandwidth-version of the material item, marked with a code word from a predetermined set of code words. The data processing apparatus is operable to form an impaired version of the material item from which a marked representation of the original material item can be formed. The impaired version is formed by subtracting the reduced-bandwidth-version of the material item from a copy of the original material item. As such, the impaired version can be mass distributed, but a representation of the original material item cannot be formed without the reduced-bandwidth-version of the material item.

Abstract: A data processing apparatus is provided for detecting distortion of a data signal to which a template signal has been introduced into different frequency bands of the signal. The apparatus includes a frequency component processor operable to generate data representative of the frequency components of the first and the second frequency bands of the data signal, and a detection processor operable to identify the distortion of the data signal in accordance with a relative frequency change between the versions of the recovered template signal.

Abstract: A watermarking system comprises an encoding data processor operable to generate at least one marked version of an original item of material by introducing one of a predetermined set of code words into a copy of the original material item. The encoding processor comprises a code word generator operable to form the code word by generating a plurality of code word coefficients, and an encoder operable to combine the code word coefficients with the material item, and an adaptation processor. The adaptation processor is operable to adapt the strength of the code word coefficients or the material item samples in accordance with a relative sensitivity of the material item samples to carry the code word coefficients. The strength of the watermark is therefore adapted in accordance with the sensitivity of the material item to carry watermark code word coefficients. As a result there is a reduced likelihood of an attacker identifying parts of the material item to which the watermark code word has been added.

Abstract: A watermarking system includes an encoding data processor operable to generate at least one marked version of an original item of material by introducing one of a predetermined set of code words into a copy of the original material item. The apparatus has a code word generator operable to provide the code word having a plurality of code word coefficients, and an encoding processor operable to combine the code word coefficients with the material. Each of the plurality of code words of the set is uniquely associated with a data word having first and second fields. Each of a set of values of the first field is represented as a first part of the code word having a first plurality of coefficients, and the second field is represented as a second part of the code word having a second plurality of coefficients.

Abstract: An encoding data processing apparatus generates at least one water marked version of an original item of material formed by introducing one of a predetermined set of code words into a copy of the original material item. The apparatus has a bandwidth adaptation processor configured to adapt a bandwidth of the code word to at least part of a bandwidth of the original material item, and an encoder configured to combine the bandwidth adapted code word with a copy of the original material item. The probability of correctly detecting a code word is improved by combining the code word with a part of the bandwidth of the material item. As a result, if the material is transformed in some way the code word may still be detected.