Lucent Technologies Inc.

At+t Corp.

At&t Bell Laboratories

Agere Systems Inc.

Alcatel-Lucent USA Inc.

Christine Irene Podilchuk

Arnaud Eric Jacquin

Hui-Ling Lou

Nuggehally Sampath Jayant

John Hartung

Raghavan Anand

Sergio Daniel Servetto

Thomas A Michel

Sanghoon Lee

Xiaoyu Zhang

Jihwan Patrick Choi

Hosam Adel Khalil

Soo-Chul Han

A method for improving real-time video communications using a Foveation-based unequal error protection scheme (UEP) and error resilience. In a preferred embodiment of the present invention, a real time processing module partitions a video image into at least two data bit stream signals based on a directional pointing device or a pattern filter definition of 'areas of importance.' These different data bit stream signals are then processed via different algorithms based on the importance of correcting errors in the data signals. The data is then transmitted. After reception at a receiving device, the data signals are regenerated and corrected to their original form.

Foveation-based error resilience algorithm

An encoder generates an estimate of apparent inter-image motion utilizing a dense motion field in a sequence of video frames or other images. The estimate in an illustrative embodiment includes a motion vector for each pixel of the dense motion field. The estimate is generated at least in part as a solution to a constrained optimization problem based on a multiscale data model characterizing the motion between pixels of the dense motion field and designated neighbor pixels. The estimate is used for motion compensation in encoding the corresponding images, and is itself encoded for transmission to a decoder for use in decoding the encoded images. In the illustrative embodiment, the multiscale data model characterizes spatial, temporal and scale coherence properties of the motion as a Markov random field (MRF), thereby ensuring that the resulting motion vectors can be efficiently coded for transmission to the decoder.

Method and apparatus for dense motion field based coding

A video signal is encoded in a progressive video coder so as to generate a progressive coded video bit stream for transmission over a heterogeneous network. The progressive coded video bit stream is configured so as to be decodable at any one of a series of increasing bit rates up to a maximum bit rate, depending on which of a number of corresponding portions of the progressive coded video bit stream are received by a decoder. Each of the portions is associated with a different bit rate, and one or more of the portions may each also be associated with different values of other parameters such as frame rate, spatial resolution, and peak signal-to-noise ratio. Each of the series of increasing bit rates produces progressively better reconstructed video quality at an output of the decoder. The progressive coded bit stream is transmitted over a first part of the heterogeneous network at a first one of the bit rates. One or more selected portions of the progressive coded video bit stream are then transmitted from the first part of the heterogeneous network to a second part of the heterogeneous network. The selected portions are associated with a second one of the bit rates lower than the first bit rate, and may be selected based on an error detected in the transmission over the first part of the heterogeneous network, and/or a characteristic of the second part of the heterogeneous network. The invention provides efficient bit rate scalability and adaptability and is particularly well-suited for use in conjunction with transmission over heterogeneous wired-to-wireless networks.

Method and apparatus for video transmission over a heterogeneous network using progressive video coding

An encoding method for reducing motion video data sizes using a multitude of variable-sized data blocks that are derived from spatial translation vectors and the motion field of an image. Using variable-block sizes to characterize the groups of picture elements (pixels) in an image frame allows for the inter-mixing of coarse (for static areas) and fine (for areas of complex motion) resolution data descriptions in the same descriptive data block. A comparison of motion event areas is made between successive video frames, and a motion displacement vector is calculated for each pixel location in the frame. A data tree is constructed from these pixel motion vectors and is pruned to eliminate static areas. The remaining leaves of the pruned tree are encoded differentially and applied to a lossless arithmetic encoder to provide a significantly reduced data block that still retains the highest resolution of the image.

Motion estimation and compensation for video compression

Digital watermark information is inserted into an image by first separating the image into components, e.g., discrete cosine transform (DCT) blocks or image subbands, and then associating one or more bits of the digital watermark information with each of the components. For example, a single bit may be associated with each of the components by modulating the components with selected waveforms representative of the corresponding digital watermark information bits. As another example, the digital watermark information bits may be coded, e.g., using a repetition code, linear block code or convolutional code, to form channel bits, such that the modulating waveforms are selected for the image components based on the corresponding channel bits. The digital watermark information may include a total of B bits of information for representing a particular watermark, such that M&equals;2 distinct watermarks can be generated using the B information bits. The invention also provides techniques for determining an upper bound on the number of distinct watermarks that can be reliably detected in a given embodiment, as a function of the noise variance of a potential jammer.

High-capacity digital image watermarking based on waveform modulation of image components

Channel error protection is provided for a source coded bit stream in a communication system by a combination of outer channel coding and inner channel coding implemented across different network layers of the system. One or more of a number of different portions of the source coded bit stream are outer channel coded in a first network layer of the system, e.g., an application layer, using a designated outer channel code, so as to provide an outer channel coded bit stream having different levels of error protection for each of the different portions of the source coded bit stream. The outer channel coded bit stream is then inner channel coded in a second network layer of the system, e.g., a physical layer, using a designated inner channel code to thereby generate a channel coded bit stream. The channel coded bit stream may then be subject to further processing operations prior to transmission in the communication system. Advantageously, the invention allows unequal channel error protection to be provided for source coded audio, image, video or multimedia bit streams in a standard second generation (2G) or third generation (3G) wireless system in a manner which is independent of the physical layer coding infrastructure of the system.

Channel error protection implementable across network layers in a communication system

Unequal channel error protection is provided for a bit stream, e.g., a progressive source coded bit stream, by puncturing of a channel code. The channel code has a specified rate associated with a corresponding level of error protection, and is used to code a first portion of the bit stream. The channel code is subsequently punctured for at least a second portion of the bit stream so as to provide a rate higher than that of the designated rate. Commencement of the puncturing is deliberately delayed by an amount determined based at least in part on a memory of the channel code. Advantageously, the delay prevents propagation of errors in a channel decoder used to decode the channel coded bit stream. The progressive bit stream may be a progressive source coded video or audio bit stream, any other type of progressive information bit stream, or a partitioned source coded bit stream.

Method and apparatus for providing channel error protection for a source coded bit stream

A method for optimizing a wavelet packet structure for subsequent tree-structured coding which preserves coherent spatial relationships between parent coefficients and their respective four offspring at each step. A valid frequency tree is defined by a wavelet packet decomposition algorithm. Constraints are placed on the pruning of the frequency tree in order to select valid frequency trees as each step. These constraints include considering any four offspring sub-bands as candidates for pruning only when their current frequency decomposition level is the same as that of their respective spatially co-located parent sub-band, and pruning the spatially co-located offspring sub-bands when pruning only the parents results in an invalid wavelet packet structure.

Constrained wavelet packet for tree-structured video coders

A method and apparatus for recognition of objects such as faces in images using signal compression techniques (i.e., coding techniques) in which a portion of the image which includes the object to be recognized (e.g., the face) is coded, and the resultant coded data is matched against previously coded and stored training data which makes up a known object database. A given object in an input image signal is matched to one of a plurality of known objects stored in a database, wherein the stored representation of each of the known objects comprises a codebook generated based on training image signals comprising the known object. A first illustrative embodiment comprises the steps of decomposing the given object into blocks; performing a plurality of encodings of the given object, each encoding comprising coding the object with use of one of the codebooks; determining a coding error for each encoding; and matching the given object to one of the known objects based on the coding errors. A second illustrative embodiment comprises the steps of decomposing the given object into blocks; generating a codebook corresponding to the given object based on the blocks; comparing the codebook corresponding to the given object with the codebooks corresponding to each of the known objects; and matching the given object to one of the known objects based on the comparison of the codebooks.

Face recognition using DCT-based feature vectors

A method and apparatus for low bit rate coding of color video signals in which the use of the codebook entry identified by the codebook index may be bypassed in the coding of chrominance information when it is determined that it is advantageous to do so. In particular and in accordance with an illustrative embodiment of the present invention, the method comprises the steps of generating a codebook index signal based on the luminance information of the block being coded; determining a coding error based on a comparison of the chrominance information contained in the given block and the chrominance vector represented by the generated codebook index signal; and generating a chrominance vector bypass signal based on whether the coding error exceeds a threshold. Specifically, the chrominance vector bypass signal is used to indicate whether the chrominance information of the given block has or has not been coded with use of the codebook. In one illustrative embodiment, the motion-compensated interframe prediction for the given block is used (without any interframe codebook difference vector adjustment) to code the chrominance signal when the chrominance data from the indexed codebook entry is not used (i.e., when it is bypassed).

Color video vector quantization with chrominance codebook bypass

A method of coding a set of multi- level signals, such as video signals comprises filtering the set of multi-level signals into one or more sets of multi-level sub-band signals; allocating a first quantity of bits for use in coding a first set of sub-band signals; coding the first set of multi-level sub-band signals using zero or more of the first quantity of allocated bits; allocating a second quantity of bits for use in coding a second set of sub-band signals, the second quantity of bits comprising zero or more of the first quantity of bits not used in coding the first set of multi-level sub-band signals; and coding the second set of multi-level sub-band signals using zero or more of the second quantity of allocated bits. Three examples of the method am provided. A hardware implementation involving the use of digital signal processors operating in parallel is also provided.

Method and apparatus for synthesizing subband video images

A geometric vector quantizer coding technique is illustrated in the context of a full motion video coder based on a three-dimensional sub-band framework. The original image data is decomposed into different spatial-temporal frequency bands and based on the data in each band, different quantization strategies are applied to the bands. The lowest spatial-temporal frequency band is coded using a traditional three-dimensional switched predictor and optimum scaler quantizer. The non-dominant sub-bands are coded using the vector quantization approach to efficiently encode the images while appropriately exploiting the sparse, highly structured nature of the data to design the codebooks. Variable resolution is achieved using these techniques and no training is needed to establish or maintain the codebook. A fast codebook search technique is provided for identifying the optimal codebook vector for representing a block of input data. Examples of two and three level geometric vector quantizers are also provided.

Geometric vector quantization

The present invention provides a method of coding a set of multi-level signals, such as video signals. The method comprises filtering the set of multi-level signals into one or more sets of multi-level sub-band signals; allocating a first quantity of bits for use in coding a first set of sub-band signals; coding the first set of multi-level sub-band signals using zero or more of the first quantity of allocated bits; allocating a second quantity of bits for use in coding a second set of sub-band signals, the second quantity of bits comprising zero or more of the first quantity of bits not used in coding the first set of multi-level sub-band signals; and coding the second set of multi-level sub-band signals using zero or more of the second quantity of allocated bits. Three examples of the method are provided. A hardware implementation involving the use of digital signal processors operating in parallel is also provided.

Dynamic bit allocation for three-dimensional subband video coding

A geometric vector quantizer coding technique is illustrated in the context of a full motion video coder based on a three-dimensional sub-band framework. The original image data is decomposed into different spatial-temporal frequency bands and based on the data in each, different quantization strategies are applied to the bands. The lowest spatial-temporal frequency band is coded using a traditional three-dimensional switched predictor and optimum scaler quantizer. The non-dominant sub-bands are coded using the vector quantization approach to efficiently encode the images while appropriately exploiting the sparse, highly structured nature of the data to design the codebooks. Variable resolution is achieved using these techniques and no training is needed to establish or maintain the codebook.

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Bridgewater, NJ, United States of America

Christine Irene Podilchuk