Abstract: A material distribution apparatus, comprising a material server including a data introduction processor operable to introduce data into material to be distributed with the effect that the introduced data is at least difficult to perceive in the material, and a material impairment processor operable to introduce a reversible impairment into the material. A communications network distributes the impaired material to at least one client processor which includes an impairment reversing processor operable to reverse the impairment of the material to produce client restored material.

Abstract: A system for facilitating copyright protection of material includes an apparatus for detecting the presence or absence of a block of data, which may have been embedded repeatedly a predetermined number of times in the material. The presence or absence of the data block is detected from data representative of versions of the data block recovered from the material. The apparatus comprises an accumulator operable to combine the value of the bit at each corresponding position within each recovered version of the data block to generate for each bit an accumulated score. A detection processor is operable to compare the value of the accumulated scores for the bits of the block with at least one threshold, and from the comparison determine a total number of detected bits of the data block. The detection processor declares the data block as being present or absent in dependence upon the total number of detected bits.

Abstract: An image processing apparatus is operable to embed data into an image. The apparatus comprises a combining processor operable to introduce the data into a transform domain representation providing a plurality of sub-bands divided by spatial frequency components, and, in combination with a transform processor, to combine the data with the image in one of a transform domain form, the transform processor generating a transform domain form of the image, the data being combined with the image by the combining processor in the transform domain, and the transform processor generating a spatial domain representation of the combined image and data, or a spatial domain form of the image, the transform processor generating a spatial domain representation of the transform domain data, the data being combined with the image by the combining processor in the spatial domain.

Abstract: A data encoding apparatus operable to encode a plurality of data blocks produces encoded data in accordance with at least one of a selectable target data quantity or a selectable target data quality.

Abstract: An apparatus for detecting and recovering data embedded in information material, the data having been embedded in the material in a transform domain representation by arranging for the data to modulate a predetermined data sequence to form modulated data and combining the modulated data with the material. The apparatus comprises a transform processor operable to transform the material into the transform domain representation, and a correlation processor operable to correlate transform domain data symbols bearing the modulated data with a reproduced version of the predetermined data sequence to form a correlation output signal and to recover the embedded data from the correlation output signal. The correlation processor is operable to repeat the correlation for transform domain data symbols and data symbols of the predetermined data sequence for each of a plurality of start positions in the transform domain.

Abstract: A method of embedding data in material comprises the steps of:

Abstract: Material is represented by transform coefficients represented by digital numbers. A method of perceptibly watermarking the material comprises the steps of: changing representations of the said numbers according to an invertible algorithm without changing the number of bits in the said numbers; and encoding the changed n bit numbers to effect compression encoding of the material.

Abstract: A spatial domain image I produced by a source 1 is combined with watermark data Ri to produce a spatial domain watermarked image I′.

Abstract: A desk that contains an integrated computer. The desk includes a screen and a keyboard that are attached to a frame. The desk may also have a backplane located in a slot of the frame. A portable transporter computer can be plugged into the backplane to couple the transporter with the screen and keyboard. A battery module may also be plugged into the frame to power the transporter, screen and keyboard. When the desk is not in use the battery module can be plugged into a charging station to recharge the batteries of the module.

Abstract: A system for watermarking and transferring watermarked material comprises a transaction server, first and second clients, first apparatus for applying a perceptible watermark to the material and second apparatus for removing the watermark. The server, clients and first and second apparatus are linked by one or more communications networks.

Abstract: A data processor is operable to represent data symbols from a data source as modelled data symbols. The data source has first component data (R) and second component data (G), the first component data being related to the second component data. The data processor comprises a prediction processor operable to generate first modelled data symbols representative of the first component data symbols, by predicting each of the first component data symbols from the second component data symbols.