Abstract: A method is disclosed for compressing an HDTV signal (1) in such a manner that it can be recorded and edited with SDTV equipment (4,5). More particularly, the HDTV signal is recorded on digital recorders (e.g. DVCPRO) which have been designed for recording compressed SDTV signals. A sub-sampled version of the HDTV signal is recorded in first locations (20) of compressed macroblocks in a manner complying with the relevant SDTV recording format. The HDTV signal is compressed (2) and formatted (3) for being recorded in further locations (21). Between said first and further locations, an end-of-block code (28) is recorded so that the recorder (4) will ignore the HDTV data. Upon playback, a recognizable version of the sub-sampled HDTV signal is displayed on an SDTV receiver (5). Readily available SDTV equipment can thus be used for HDTV editing. In one embodiment of the invention, the sub-sampled HDTV signal consists of selected DC coefficients.

Abstract: Disclosed is a method of compressing information for storage in a fixed size memory. The data items (D(k)) that constitute the information are divided into pieces (D(s,k)) of decreasing significance. For example, the DCT blocks of an image are hierarchically quantized (3). The memory (5) is organized in corresponding memory layers (501-504). Successive memory layers have a decreasing number of memory locations. Every time a data item is applied to the memory, its less significant data pieces will have to compete with corresponding data pieces of previously stored data items. Depending on its contribution to perceptual image quality, the applied data piece is stored or the stored data piece is kept. Links (511-513, 521-522) are stored in the memory to identify the path along which a data item is stored. Eventually, the image is automatically compressed so as to exactly fit in the memory. FIG. 2.

Abstract: A pixel value for a pixel is computed in a texture mapped computer graphics image. Surface coordinates are computed that map to a location of intersection of a 3D surface with a line of sight from the pixel. A surface coordinate offset vector is computed that represents a change in the surface coordinates of the intersection, the change corresponding to displacement of the surface by an amount specified by a displacement map value for the surface coordinates. The pixel value is computed in the computer graphics image from a texture value defined for said surface coordinates offset by said offset vector.

Abstract: In the Improved PB-frames mode, one of the options of the H.263+ Recommendation, a macroblock of a B-frame may be encoded according to a forward, a backward or a bidirectional prediction mode. The invention relates to a method of encoding a sequence of pictures defining a strategy for the choice of a prediction mode among the three possible ones in the encoding of B-macroblock. This strategy is based upon SAD(Sum of Absolute Difference) calculations and motion vectors coherence and allows to use backward prediction when scene cuts occur. In the proposed strategy, the SAD of the bidirectional prediction is not necessarily derived when the motion is non linear allowing less calculation and reduction in CPU burden. The invention also relates to an encoding system for carrying out said method and including a computer-readable medium storing instructions that allow the implementation of this method.

Abstract: The invention relates to a device for demultiplexing coded data corresponding to multimedia objects. The data is organized in a bitstream divided into individually accessible portions—for instance Access Units for an MPEG-4 compliant bitstream—themselves subdivided into smaller data entities—SL-packets in the cited example—which all the demultiplexing operations are applied to. The operations are mainly, for all the data received at the input of the demultiplexing device: reading and formatting of a buffer, extraction of successive Access Unit segments, progressive reconstruction of a complete Access Unit, transmission of the Access Unit to an output buffer or file.

Abstract: The invention relates to a method of coding segmented pictures, or partitions, divided into homogeneous regions. Said method, called intra-mode coding process, comprises, for each successive partition, the steps of translating the picture of the labels associated to the regions into a description in terms of a contour element chain in which the elements are defined by means of their movements through successive basic cells, tracking inside each successive cell each contour from its initial contour point, previously extracted, to its end by storing chain symbols corresponding both to input, internal and output contour elements of said cell and to priorities between possible multiple outputs elements, and repeating these steps up to the end of each successive contour segment of the concerned partition.

Abstract: The variable bitrate coding method according to the invention includes an iterative process including a first coding pass and a second prediction pass. The coding pass allows for a picture coding of a sequence with a constant quantization stepsize (and quality) and the prediction pass allows for a matching of the stepsize to the wanted target bitrate. After some iterations, a last step allows for a finer adjustment of said stepsize with respect to said target bitrate.

Abstract: The present invention is directed to a reconfigurable finite impulse response (FIR) filter that processes data tap values with canonical sign digit (CSD) coefficients. The FIR filter according to the present invention includes a shift group associated with at least one of the data tap values and at least one of the CSD coefficients. Each shift group includes a plurality of parallel paths. Each parallel path shifts the data tap value according to a bit pair of the coefficient to produce a weighted product. An adder is also included that combines the weighted products from each of the shift groups.

Abstract: A system and method for scaling a video system, such as an MPEG-2 video decoder, utilizing an improved data pruning implementation. A scalable data processing system is provided, comprising: a sequential data path for processing multimedia data, including a first processing module and a second processing module; a scalable application for scaling the second processing module; and a data pruning system positioned prior to the first processing module that causes a portion of the multimedia data associated with the scaling application to be truncated.

Abstract: Data is hidden in an information signal by encoding payload in to relative positions and/or polarities of multiple (possibly equal) embedded watermarks. The payload is retrieved by computing the correlation between the watermark(s) and the signal as a function of the position. The distance between peaks of the correlation function represents the payload. In order to precisely detect said distance, even if the peaks are smeared, the correlation function in a window (w1) around one peak (p1) is compared with the correlation function in a similar window (w2) around another peak (p2). This is done for different positions of said windows. The distance (k) between the windows (37,38) for which the correlation functions most resemble each other is the distance representing the payload.

Abstract: A quantizer is disclosed in which the quantization errors are symmetrically divided around the respective reconstruction levels. The quantizer prevents quantization errors from accumulating when the quantizer operates in a recursive loop. This is important if such a quantizer is used, inter alia, for compressing image data in the prediction loop of an MPEG decoder. The quantizer prevents such a decoder from drifting away from the encoder's local prediction loop.

Abstract: The invention relates to a video coding method based on an adaptive frame/field encoding mode. In order to avoid an impairment of the image quality and of the compression efficiency when a video sequence comprises a lot of motion or on the contrary quasi-motionless images, an improved real time double pass encoding scheme is proposed: during the first pass, no video stream is generated, but statistical results are computed and then provided to the second pass in order to optimize during said second pass the bit rate allocation and the buffer management. This improved double pass encoding method leads to an increase of the compression efficiency of about 10%.

Abstract: A method and apparatus for reclaiming memory space allocated to data structures comprising data objects linked by identifying pointers. A repetitious cycle is performed including the following steps of traversing the data structures to identify and mark active data objects, deleting data objects that were marked as garbage during the previous cycle, marking data objects not marked as active as garbage, and executing the finalizer of any data object marked as garbage having a finalizer.

Abstract: A data compression assembly has several data-compression channels (DCC). The data-compression channels may be, for example, encoders which encode different programs in accordance with an MPEG standard. A data-compression channel comprises a data compressor (CMP) and a buffer-memory space (BUF). The data compressor compresses input data (D) so as to obtain compressed data (Dc). The buffer-memory space temporarily stores the compressed data and provides the compressed data in the form of an output data stream (DS). Indications (IND) of compressed-data quality (Q[Dc]) versus extent of compression (E[CMP]) are established for respective data-compression channels. A total output bit rate (Rtot) is partitioned over respective output data streams in dependence on these indications. The extent of compression in respective data-compression channels is controlled individually on the basis of output data stream bit rate (R) and amount of compressed data (F) stored in the buffer memory space.

Abstract: The present invention relates to a method of playing a set of multimedia applications (A), each multimedia application including a list of tasks (TTD). The method includes the steps of creating a common scheduler (SCH) at a start time, in order to provide a target time, registering the tasks into the scheduler, and controlling the execution of the tasks as a function of the target time. The method also includes a step of giving a priority level to the task and the scheduler is adapted to control the execution of the tasks as a function of the target time and the priority level. The method further includes a step of computing a local time for a task from the target time provided by the scheduler and timing information associated with said task. With such a mechanism, each task has its own time reference, thus ensuring a correct operation of the overall application, while a global notion of schedule is maintained.

Abstract: A method of selective telephone caller identification includes the steps of providing a list of telephone numbers of second parties to which a first party is willing to release identification information regarding the first party (101). This list is supplied to, and stored in a database of, a telephone company by the request of the first party if the first party subscribes to a call blocking service with the telephone company (102). When the first party dials a telephone number (104), the telephone company determines whether the first party subscribes to the call blocking service (105). If yes, the telephone company searches the list in the database to determine if the dialed telephone number is on the list (106). When it is determined that the first party subscribes to the call blocking service and the dialed telephone number is not on the list, the telephone ID information is blocked by the telephone company (111).

Abstract: When embedded memory compression is used in the recursive loop of a predictive (MPEG) encoder/decoder, a given compression factor must be achieved. To this end, the image is divided in segments, i.e. groups of (macro)blocks. Each segment is feedforward coded using a quantization strategy such that the compression factor is achieved. This leaves spare bits in the (fixed) segment size. In accordance with the invention, the space left unused by segments is used for refining the quantization of segments having a higher than average activity.

Abstract: There is disclosed an image processing device capable of receiving an image file having a first texture representation in rotation variant format and converting the texture representation to a modified texture representation in a rotation invariant format. The image processing device comprises an image processor for analyzing rotation variant texture parameters in the first texture representation and converting them to 1) rotation invariant texture parameters disposed in circular rings about a selected pixel; or 2)rotation invariant texture parameters disposed along radial lines extending through the selected pixel. In the second embodiment, the image processor can use the angular separation of the radial lines to determine the angular rotation of a rotated version of the image file.

Abstract: The invention relates to a system for transmitting packets from interactive terminals to a head station. The terminals intended for consumers are provided with local oscillators which are not very accurate and use carriers having frequency errors which are relatively large with respect to the theoretical reference value (Fp). The invention provides an improvement of the reception of signals having such a frequency shift at the receiver end. To this end, the invention provides a method of estimating the frequency error &Dgr;{circumflex over (f)}, which consists of rapidly obtaining the maximum value of a discrete error function denoted Z(&Dgr;{circumflex over (f)}) for a given accuracy (Acc) by computing the function Z(&Dgr;{circumflex over (f)}) for a minimal number of points.

Abstract: The invention relates to a method of and apparatus for displaying an electronic program guide. The method includes the step of displaying an axis (21) on the screen (20) which corresponds to a particular program attribute (e.g. channel name, broadcast time, program category, program title). The user may select a value from the axis, causing a pictogram (27) to be displayed, showing information about programs corresponding to the selected value. The pictogram's position corresponds to the position of the selected value. A new value may be selected by dragging the pictogram and/or shifting the axis.