Abstract: There is disclosed a content protection method and apparatus. The content protection method and apparatus further improves such related schemes by facilitating spatial as well as temporal management of content. This is achieved by storing encrypted content and a corresponding decryption key and destroying the decryption key when suitable. In order to further facilitate the content protection, the decryption key may be received periodically, which allows for a large number of people to connect to the network at different times.

Abstract: There is disclosed a distribution network and method. This is particularly advantageous because the network allows highlight clips to be generated and distributed quickly. Additionally, the highlights are more consistent because the user selects the event (from which the highlight is formed) from a list of possible event selections. This also has the advantage that there is the reduced likelihood of the individual generating the events missing any other incidents requiring highlighting.

Abstract: A system communicates a representation of a scene, which includes a plurality of objects disposed on a plane, to one or more client devices. The representation is generated from one or more video images of the scene captured by a video camera. The system comprises an image processing apparatus operable to receive the video images of the scene which includes a view of the objects on the plane, to process the captured video images so as to extract one or more image features from each object, to compare the one or more image features with sample image features from a predetermined set of possible example objects which the video images may contain, to identify the objects from the comparison of the image features with the predetermined image features of the possible example objects, and to generate object path data for each object which identifies the respective object; and provides a position of the identified object on a three dimensional model of the plane in the video images with respect to time.

Abstract: A camera arrangement comprising a plurality of camera elements and a corresponding method of arranging camera elements is described. The camera arrangement improves the resolution of a stitched image by maintaining a uniform overlap between the fields of view of adjacent camera element. The uniform overlap is achieved. This is because the amount of unnecessary overlap required to achieve the required degree of overlap is reduced.

Abstract: A method of synchronising the phase of a local image synchronisation signal generator of a local video data processor in communication with an asynchronous switched packet network to the phase of a reference image synchronisation signal generator of a reference video data processor also coupled to the network, the local and reference processors having respective clocks, the reference and local image synchronisation signal generators generating periodic image synchronisation signals in synchronism with the reference and local clocks respectively comprises the steps of:

Abstract: An image processing apparatus operates to process input signal samples representative of at least part of a colour video image to produce legal colour signal samples representative of a legal colour version of the image. The apparatus comprises an adjustment factor generator, which operates to generate a plurality of adjustment factors which when combined with the input signal samples have an effect of converting illegal colour pixels of the colour image into legal colour pixels, an adjustment factor softener, which operates to soften the adjustment factors whereby distortion in the legal colour video image produced when the adjustment factors are combined with the input signal samples is substantially reduced, and a colour legaliser coupled to the softener, which operates to combine the softened adjustment factors with the input signal samples to produce the legalised colour signal samples.

Abstract: Video data compression apparatus comprises means for detecting image activity values indicative of image activity for regions of an input image to be compressed; means for filtering the detected image activity values to reduce the variation in image activity values between groups of adjacent regions of the image; and means for compressing the regions of the image by a degree of data compression dependent on the image activity value for each region.

Abstract: A digital video processing system and method for deriving an output compressed video signal from an input compressed video signal. The input compressed video signal represents successive input pictures. Subsets of the input pictures are derived from other input pictures according to input picture motion vectors corresponding to a repetitive GOP (Group of Pictures) structure. The output compressed video signal represents successive output pictures, subsets of the output pictures being derived from other output pictures according to output picture motion vectors corresponding to a repetitive GOP structure that is different from, or not picture-aligned with, the GOP structure of the input compressed video signal. The output picture motion vectors are derived from the input picture motion vectors.

Abstract: Video data compression apparatus in which successive groups of two or more images are encoded subject to a predetermined limit on the quantity of output encoded data to be generated for each group of images, comprises a trial encoder for encoding at least a subset of images of a current group of images to generate trial-encoded data for each trial-encoded image; a data quantity allocator, responsive to the quantities of trial-encoded data generated by the trial encoder, for allocating respective quantities of output encoded data for each image in the group of images; and a final encoder for encoding each image of the group of images in accordance with the quantities of output encoded data allocated to that image by the data quantity allocator.

Abstract: A video data compression system uses a wavelet transform circuit (580) but otherwise operates in the manner of an MPEG II compression system. The compressed data is stored on a medium such a tape by e.g. digital video tape recorder (3), which medium and recorder may subject that data to errors by virtue of head failures and/or tape defects. Means (5) are provided to produce concealment data indicative of the form of concealment to be used if data is lost during reproduction. A variety of concealment techniques are used. Some of the transformed data is frequency inverted during transformation. Such data is subject to high pass filtering to conceal errors. Concealment data indicates the most appropriate form of concealment to be used in the event of an error is produced before recording and recorded with the data. The concealment data is recorded on a track different to the track of the data with which it is associated.

Abstract: Video data compression apparatus in which successive groups of two or more images are encoded subject to a predetermined limit on the quantity of output encoded data to be generated for each group of images, comprises a trial encoder for encoding at least a subset of images of a current group of images to generate trial-encoded data for each trial-encoded image; a data quantity allocator, responsive to the quantities of trial-encoded data generated by the trial encoder, for allocating respective quantities of output encoded data for each image in the group of images; and a final encoder for encoding each image of the group of images in accordance with the quantities of output encoded data allocated to that image by the data quantity allocator.

Abstract: Image data compression apparatus in which data is encoded using a variable degree of quantization selected for areas of an image so that the quantity of encoded data for each area does not exceed a predetermined maximum quantity of data comprises two or more trial encoders operable in parallel to trial encode image data using respective predetermined trial degrees of quantization; a selector for selecting one of the predetermined trial degrees of quantization in response to the quantities of data produced during the trial quantizations; and one or more further trial encoders operable to trial encode image data using degrees of quantization derived from the degree of quantization selected by the selector.

Abstract: Video data compression apparatus in which successive groups of two or more images are encoded subject to a predetermined limit on the quantity of output encoded data to be generated for each group of images, comprises a trial encoder for encoding at least a subset of images of a current group of images to generate trial-encoded data for each trial-encoded image; a data quantity allocator, responsive to the quantities of trial-encoded data generated by the trial encoder, for allocating respective quantities of output encoded data for each image in the group of images; and a final encoder for encoding each image of the group of images in accordance with the quantities of output encoded data allocated to that image by the data quantity allocator.

Abstract: Image data compression apparatus comprises a data compressor for receiving data representing sub-areas of an input image and for generating respective blocks of compressed data representing those sub-areas, each block of compressed data comprising at least low spatial frequency image data and higher spatial frequency image data; a data formatter for formatting predetermined groups of said blocks of compressed data into output data blocks, said data formatter having a predetermined data capacity; a detector for detecting whether a current group of said blocks of compressed data contains more data than said data capacity of said data formatter; and a block truncator, responsive to a detection that a current group of said blocks of compressed data contains more data than said data capacity of said data formatter, for truncating one or more of said blocks of compressed data by discarding at least said higher spatial frequency image data.

Abstract: Image data compression apparatus for generating groups of encoded image data representing respective sub-areas of an image, in which the degree of data compression applied to each sub-area is specified at least in part by an attribute value associated with that sub-area, comprises selection logic for selecting the attribute value to be associated with each sub-area of an image; an attribute encoder for encoding the attribute value for each sub-area of the image according to a selected one of a plurality of predetermined sets of attribute codes, different sets of attribute codes being encoded using different respective quantities of data; a comparator for comparing attribute values for a group of the data blocks to detect whether the attribute values for the group of sub-areas could be encoded using a replacement one of said sets of attribute codes requiring a smaller quantity of data; and replacing logic responsive to a detection that the attribute values for the group of sub-areas could be encoded using a re

Abstract: An apparatus for recording video data with a multi-level arrangement of error correction coding. Input video data is demultiplexed so as to form a plurality of data streams each having a plurality of data blocks. A stream error correcting code is generated for each of the plurality of data streams, which is adaptable to allow correction of a data block. The respective data blocks and stream error correcting code of each data stream is distributed or arranged in a predetermined manner. The distributed data blocks and stream error correcting code of each data stream are recorded on recording tracks of a recording medium by n recording heads such that only either a data block or a stream error correcting code of a respective data stream is recorded at corresponding positions along n adjacent recording tracks of the recording medium.

Abstract: Video data compression apparatus in which successive images are encoded, comprises a data quantity allocator for allocating respective quantities of output encoded data for two or more complementary areas of each image; and an encoder for encoding each area of each image of the group of images in accordance with the quantity of output encoded data allocated to that area.

Abstract: Apparatus for frequency-separating input image data, the apparatus comprises a data buffer; a multi-stage filter for performing successive spatial filtering operations on input image data, the multi-stage filter having:(i) a first filtering stage for frequency-separating the input image data into image data representing at least two spatial frequency bands; and(ii) one or more subsequent filtering stages for receiving a subset of image data output by the preceding stage and frequency-separating that image data into image data representing two or more spatial frequency bands;in which data output by each stage which is not part of the subset of the image data to be filtered by a subsequent filtering stage is supplied to the data buffer; and means for combining image data output by the last of the filtering stages and image data buffered in the data buffer.

Abstract: A charge-coupled image sensor having adjacent image acquisition and image storage areas is described. Pixel transfer can take place from the image acquisition area to the image storage area and from the image storage area to an output register simultaneously and at different respective transfer rates. This allows the image transfer into the storage area to begin during the active field period, i.e. while pixels are still being transferred from the storage area into the output register. In a preferred embodiment this is achieved by partitioning the image storage area into a first and a second storage section which can selectively operate at the same or different transfer clocking rates.

Abstract: Video data compression apparatus in which successive groups of two or more images are encoded, each encoded group of images including at least one intra-image encoded image and at least one inter-image encoded image. A data quantity allocator allocates respective quantities of output encoded data for each image in the group of images according to an allocation ratio between intra-image encoded images and inter-image encoded images dependent on the quantities of encoded data generated during encoding of a preceding group of images. A scene change in the group of images is detected and the allocation of output encoded data for images in a group of images is reset to a default allocation ratio if a scene change is detected in that group of images. An encoder encodes each image of the group of images in accordance with the quantities of output encoded data allocated to that image.