# En-Hui Yang, Waterloo CA

## En-Hui Yang, Waterloo CA

Patent application number | Description | Published |
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20080297379 | DETERMINATION OF COMPRESSION STATE INFORMATION FOR USE IN INTERACTIVE COMPRESSION - The invention is directed at a method and apparatus for determining compression state information which is to be used in the compression of data being transmitted between two communicating parties. The method of determining the compression state information for use in interactively compressing data comprises the steps parsing the data to determine a hierarchical data structure of the data; traversing a shared hierarchical node index to determine common compression state information entries between the hierarchical data structure and the hierarchical node index; and selecting at least one of the common compression state information entries for use in compressing the data. | 12-04-2008 |

20080298458 | METHOD AND APPARATUS FOR COMMUNICATING COMPRESSION STATE INFORMATION FOR INTERACTIVE COMPRESSION - A method and system are provided for interactive data compression using shared compression state information. Compression state information provides assistance in the compression of the data being transmitted between two communicating parties. | 12-04-2008 |

20080298459 | INTERACTIVE COMPRESSION WITH MULTIPLE UNITS OF COMPRESSION STATE INFORMATION - There is provided a method of interactive compression using multiple compression state information entries. The method comprises receiving a request for data from a communicating party; retrieving the data; identifying, for use in compressing the data, at least two compression state information entries shared between the parties to the communication; compressing the data with each of the at least two compression state information entries; determining, from the set of compression state information entries, a preferred compression state information entry that provides a greatest compression ratio; and transmitting the data, compressed in accordance with the preferred compression state information entry to the communicating party. | 12-04-2008 |

20080298699 | METHOD AND DEVICE FOR DOWN-SAMPLING A DCT IMAGE IN THE DCT DOMAIN - A method and device that uses transform matrices to down-sample a DCT image directly in the DCT domain. The transform matrices have been selected to minimize an optimization problem which is a function of the visual quality of down-sampled images obtained using the matrices and the computational complexity associated with using the transform matrices. The transform matrices comprise a row transform matrix and a column transform matrix. A down-sampled image is produced by determining an intermediary matrix as the product of the DCT image and one of either the row transform matrix or the column transform matrix and then determining the down-sampled image as the product of the intermediary matrix and the transform matrix not already used to determine the intermediary matrix. | 12-04-2008 |

20080298700 | METHOD AND DEVICE FOR SELECTING TRANSFORM MATRICES FOR DOWN-SAMPLING DCT IMAGE USING LEARNING WITH FORGETTING ALGORITHM - Down-sampling of an image may be performed in the DCT domain. A multiple layered network is used to select transform matrices for down-sampling a DCT image of size M×N to a DCT image of size I×J. A spatial domain down-sampling method is selected and applied to the DCT image to produce a down-sampled DCT reference image. A learning with forgetting algorithm is used to apply a decay to the elements of the transform matrix and select a transform matrices which solve an optimization problem. The optimization problem is a function of the visual quality of images obtained using the transform matrices and the computational complexity associated with using the transform matrices. The visual quality is a measure of the difference between the down-sampled DCT image obtained using the transform matrices and the visual quality of the DCT reference image obtained using a spatial domain down-sampling method. | 12-04-2008 |

20080298701 | Method and Device for Selecting Optimal Transform Matrices for Down-sampling DCT image - Down-sampling of an image may be performed in the DCT domain. Transform matrices are obtained for down-sampling a DCT image of size M×N to a down-sampled DCT image of size I×J. The transform matrices may be used to down-sample the DCT image directly in the DCT domain. A spatial domain down-sampling method is selected and applied to the DCT image to produce a down-sampled DCT reference image. The transform matrices are selected by solving an optimization problem, leading to transform matrices which achieve a desired trade-off between the visual quality of images obtained using the transform matrices and the computational complexity associated with using the transform matrices. The visual quality is a measure of the difference between the down-sampled DCT image obtained using the transform matrices and the visual quality of the DCT reference image obtained using a spatial domain down-sampling method. | 12-04-2008 |

20080301323 | SYNCHRONIZATION OF SIDE INFORMATION CACHES - In order to improve interactive compression using compression state information, the side information caches of communicating parties must be updated, or synchronized. The present invention is directed to a method of synchronizing side information databases within an interactive compression system comprising two communicating parties comprising the steps of transmitting, from the a first communicating party to the second communicating party, a device hierarchical node index; comparing the device hierarchical node index with a server hierarchical node index and then determining a shared hierarchical node index based on common entries in the two hierarchical node indexes. | 12-04-2008 |

20090021403 | METHOD AND SYSTEM FOR REDUCING CONTEXTS FOR CONTEXT BASED COMPRESSION SYSTEMS - For context based compression techniques, for example Context Based YK compression, a method and system for grouping contexts from a given context model together to create a new context model that has fewer contexts, but retains acceptable compression gains compared to the context model with more contexts is provided. According to an exemplary embodiment a set of files that are correlated to the file to be compressed (hereafter called training files) are read to determine, for an initial context model, the empirical statistics of contexts and symbols. In some embodiments, this includes determining the estimated joint and conditional probabilities of the various contexts and symbols (or blocks of symbols). The initial context model is then reduced to a desired number of contexts, for example, by applying a grouping function g to the original set of contexts to obtain a new and smaller set of contexts. In some embodiments the step of applying a grouping function comprises iteratively grouping a pair of contexts together to form a grouped context, wherein each grouped context represents a local minimum based on the empirical statistics. | 01-22-2009 |

20090103825 | ARBITRARY RATIO IMAGE RESIZING IN THE DCT DOMAIN - A method and system for arbitrary resizing of a compressed image in the discrete cosine transform (DCT) domain. First and second scaling parameters P and Q are determined in accordance with the block numbers L and M and the scaling ratio L/M or M/L. A non-uniform, or uneven, sampling in the DCT domain is then applied to coefficients of successive blocks in the compressed image in accordance with the scaling parameters. In an embodiment, P blocks are sampled and transformed from a given block length to |P| according to a |P|-point IDCT, while Q blocks are sampled and transformed from a given block length to |Q| according to a |Q|-point IDCT. The non-uniformly sampled and transformed pixel domain samples are then regrouped into a predetermined block size and transformed back to generate the DCT coefficient of the compressed image. The proposed method significantly reduces the computational complexity compared with other DCT domain arbitrary ratio image resizing approach. It also facilitates the practical implementations since only the fast implementations of IDCT with length N (1 | 04-23-2009 |

20090207937 | Method and System for Optimizing Quantization for Noisy Channels - Methods are described for configuring a quantizer to achieve improved end-to-end distortion performance when transmitting encoded source data over a noisy channel. The codebook and partitioning are selected using an iterative process of determining an updated codebook and an updated partition space, where the updated codebook is based, in part, on the average symbol error probability of the channel. Complete knowledge of the transitional probabilities of the channel is not required. Variants of the iterative process are described. | 08-20-2009 |

20090220163 | METHOD AND SYSTEM FOR DECODING ENCODED IMAGES AND REDUCING THE SIZE OF SAID IMAGES - A method and system for reducing the number of mathematical operations required in the JPEG decoding process without substantially impacting the quality of the image displayed is disclosed. Embodiments provide an efficient JPEG decoding process for the purposes of displaying an image on a display smaller than the source image, for example, the screen of a handheld device. According to one aspect of the invention, this is accomplished by reducing the amount of processing required for dequantization and inverse DCT (IDCT) by effectively reducing the size of the image in the quantized, DCT domain prior to dequantization and IDCT. This can be done, for example, by discarding unnecessary DCT index rows and columns prior to dequantization and IDCT. In one embodiment, columns from the right, and rows from the bottom are discarded such that only the top left portion of the block of quantized, and DCT coefficients are processed. | 09-03-2009 |

20090232394 | METHOD, SYSTEM AND SOFTWARE PRODUCT FOR COLOR IMAGE ENCODING - The present invention relates to the compression of color image data. A combination of hard decision pixel mapping and soft decision pixel mapping is used to jointly address both quantization distortion and compression rate while maintaining low computational complexity and compatibility with standard decoders, such as, for example, the GIF/PNG decoder. | 09-17-2009 |

20090316774 | METHOD AND APPARATUS FOR MULTI-PART INTERACTIVE COMPRESSION - In order to increase the compression of data being transmitted between two devices in communication, the data may be broken up into individual components and individually compressed using different compression state information. The method of multi-part interactive compression comprises the steps of retrieving a request for data from a communicating party; retrieving the data; parsing the data into components according to the content of the data; and compressing each of the components using compression state information. | 12-24-2009 |

20090317012 | METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR OPTIMIZATION OF DATA COMPRESSION - A method, system and computer software product for improving rate-distortion performance while remaining faithful to JPEG/MPEG syntax, involving joint optimization of Huffman tables, quantization step sizes and quantized coefficients of a JPEG/MPEG encoder. This involves finding the optimal coefficient indices in the form of (run, size) pairs. By employing an interative process including this search for optimal coefficient indices, joint improvement of run-length coding, Huffman coding and quantization table selection may be achieved. Additionally, the compression of quantized DC coefficients may also be improved using a trellis-structure. | 12-24-2009 |

20100011125 | DETERMINATION OF COMPRESSION STATE INFORMATION FOR USE IN INTERACTIVE COMPRESSION - The invention is directed at a method and apparatus for determining compression state information which is to be used in the compression of data being transmitted between two communicating parties. The method of determining the compression state information for use in interactively compressing data comprises the steps parsing the data to determine a hierarchical data structure of the data; traversing a shared hierarchical node index to determine common compression state information entries between the hierarchical data structure and the hierarchical node index; and selecting at least one of the common compression state information entries for use in compressing the data. | 01-14-2010 |

20100013677 | METHOD AND SYSTEM FOR REDUCING CONTEXTS FOR CONTEXT BASED COMPRESSION SYSTEMS - For context based compression techniques, for example Context Based YK compression, a method and system for grouping contexts from a given context model together to create a new context model that has fewer contexts, but retains acceptable compression gains compared to the context model with more contexts is provided. According to an exemplary embodiment a set of files that are correlated to the file to be compressed (hereafter called training files) are read to determine, for an initial context model, the empirical statistics of contexts and symbols. In some embodiments, this includes determining the estimated joint and conditional probabilities of the various contexts and symbols (or blocks of symbols). The initial context model is then reduced to a desired number of contexts, for example, by applying a grouping function g to the original set of contexts to obtain a new and smaller set of contexts. In some embodiments the step of applying a grouping function comprises iteratively grouping a pair of contexts together to form a grouped context, wherein each grouped context represents a local minimum based on the empirical statistics. | 01-21-2010 |

20100138225 | OPTIMIZATION OF MP3 ENCODING WITH COMPLETE DECODER COMPATIBILITY - An iterative rate-distortion optimization algorithm for MPEG I/II Layer-3 (MP3) encoding based on the method of Lagrangian multipliers. Generally, an iterative method is performed such that a global quantization step size is determined while scale factors are fixed, and thereafter the scale factors are determined while the global quantization step size is fixed. This is repeated until a calculated rate-distortion cost is within a predetermined threshold. The methods are demonstrated to be computationally efficient and the resulting bit stream is fully standard compatible. | 06-03-2010 |

20100208804 | MODIFIED ENTROPY ENCODING FOR IMAGES AND VIDEOS - A method and encoder for entropy encoding image data using a dynamically determined coding order, and a method and decoder for entropy decoding encoded data encoded using a dynamically determined coding order. The coding order for encoding quantized transform domain coefficients is dynamically determined for the image based on at least one characteristic of the quantized transform domain coefficients. The characteristic may be quantization step size if non-uniform quantization is employed for blocks of data. | 08-19-2010 |

20100208805 | ADAPTIVE QUANTIZATION WITH BALANCED PIXEL-DOMAIN DISTORTION DISTRIBUTION IN IMAGE PROCESSING - Methods and encoders and decoders for adaptively quantizing transform domain coefficients in image and/or video encoding/decoding. For an image having a number of blocks, each block having N coefficients, the quantization step size for each coefficient is selected dynamically, thus resulting in a quantizer that may apply different step sizes to different coefficients. The selected step sizes for each coefficient are used for those coefficients within all blocks in the image/frame. In one aspect, the step sizes are selected on the basis of balancing pixel domain distortion when the image/frame is decoded. | 08-19-2010 |

20100208806 | IN-LOOP DEBLOCKING FOR INTRA-CODED IMAGES OR FRAMES - Methods and encoders/decoders for applying in-loop deblocking to intra-coded images/frames. In a decoding context, a deblocking filter is applied to reconstructed pixels of an intra-coded block prior to decoding the subsequent block in the decoding sequence. In an encoding context, a deblocking filter is applied to reconstructed pixels of an intra-coded block in an inter-coding loop before encoding a subsequent block in the coding order for the image. | 08-19-2010 |

20100217605 | METHODS AND DEVICES FOR PERFORMING A FAST MODIFIED DISCRETE COSINE TRANSFORM OF AN INPUT SEQUENCE - An improved fast N-point MDCT process and encoder/decoder is disclosed. The N-point MDCT may be realized through an N/2-point DCT algorithm. The N/2 DCT transform matrix is directly factored and the factored DCT transform matrices are used to develop a set of equations for realizing the N-point MDCT coefficients from an input sequence. The factoring of the DCT transform matrix may include expressing the DCT transform as a multiplication of matrices and exploiting mirror images within the matrices. It may further include simplifying at least one of the matrices by eliminating a variable based on trigonometric identity | 08-26-2010 |

20100238997 | METHOD AND SYSTEM FOR OPTIMIZED VIDEO CODING - A method and encoder for full rate-distortion optimization of video coding over four free parameters; namely, coding mode, motion vector, quantizer scaling factor, and transform domain coefficients. In all cases, the rate-distortion cost for each combination of the parameters is determined based on soft decision quantization; specifically, a graph-based searching algorithm that reveals the optimal quantized transform domain coefficients for encoding a macroblock or sub-block of a macroblock. The full joint optimization includes a full search of the product space defined by the possible combinations of the free parameters without approximations. Approximations and simplifications to reduce complexity are also disclosed. | 09-23-2010 |

20100272373 | METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR OPTIMIZATION OF DATA COMPRESSION - A sequence of n coefficients is compressed by determining a cost-determined sequence of n coefficient indices represented by a cost-determined sequence of (run, index derivative) pairs under a given quantization table and run-index derivative coding distribution, wherein each sequence of (run, index derivative) pairs defines a corresponding sequence of coefficient indices such that (i) each index in the corresponding sequence of coefficient indices is a digital number, (ii) the corresponding sequence of coefficient indices includes a plurality of values including a special value, and (iii) each (run, index derivative) pair defines a run value representing a number of consecutive indices of the special value, and an index-based value derived from a value of the index following the number of consecutive indices of the special value. This involves (a) using the given quantization table and run-index derivative coding distribution to formulate a cost function for a plurality of possible sequences of (run, index derivative) pairs; (b) applying the cost function to each possible sequence in the plurality of possible sequences of (run, index derivative) pairs to determine an associated cost; and, (c) selecting the cost-determined sequence of (run, index derivative) pairs from the plurality of possible sequences of (run, index derivative) pairs based on the associated cost of each of the plurality of possible sequences of (run, index derivative) pairs; and encoding the corresponding selected cost-determined sequence of (run, index derivative) pairs using entropy coding based on a run-index derivative coding distribution. | 10-28-2010 |

20110019737 | SOFT DECISION AND ITERATIVE VIDEO CODING FOR MPEG AND H.264 - A method of encoding video data using soft decision quantization makes use of iterative encoding to provide the ability to optimize encoding across different functional elements in a hybrid video encoder. Iterative encoding is used to allow quantization step size, motion prediction and quantization levels to be optimized despite their interrelated nature. | 01-27-2011 |

20110106526 | METHOD AND APPARATUS FOR PRUNING SIDE INFORMATION FOR GRAMMAR-BASED COMPRESSION - A computer-implemented method for generating side information for grammar-based data compression systems, such as YK compression systems, is described. An admissible grammar (G) for an input sequence (A(s | 05-05-2011 |

20110116545 | METHODS AND DEVICES FOR IN-LOOP VIDEO DEBLOCKING - A video encoder sends at least some information regarding boundary strength to the decoder along with the bitstream of encoded video. The decoder is configured to use the received boundary strength information from the encoder to reduce the number of computations necessary for the decoder to determine the boundary strength details required for performing deblocking when decoding the bitstream. | 05-19-2011 |

20110123110 | METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR ENTROPY CONSTRAINED COLOR SPLITTING FOR PALETTE IMAGES WITH PIXEL-WISE SPLITTING - A method, system and computer program product are provided for progressively encoding a digitized color image using a data processing system, the digitized color image being provided by assigning each of the M distinct colors to at least one pixel in the set of pixels. This involves initializing and growing the tree structure by selecting a leaf node n to become a non-leaf node n linked to two new leaf nodes based on an associated achievable cost, wherein the associated achievable cost is based on 1) a determined associated change in distortion resulting from turning the leaf node into the non-leaf node linked to the two new leaf nodes; and 2) a determined associated increase in entropy rate resulting from turning the leaf node into the non-leaf node linked to the two new leaf nodes. | 05-26-2011 |

20110125506 | RATE-DISTORTION OPTIMIZATION FOR ADVANCED AUDIO CODING - A method for optimization of rate-distortion for Advanced Audio Coding (AAC). The method provides for the identification of quantized spectral coefficient sequences for optimization of rate-distortion. The method also provides joint optimization of scale factors, Huffman codebooks and quantized spectral coefficient sequences for minimization of a rate-distortion cost. The method provides an iterative rate-distortion optimization algorithm for AAC encoding. In each iteration, the method first finds the optimal scale factors and quantized spectral coefficients when Huffman codebooks are fixed, then updates Huffman codebooks and quantized spectral coefficients given the optimized scale factors. The iterations may be applied until a predetermined threshold is attained. | 05-26-2011 |

20110170598 | METHOD AND DEVICE FOR VIDEO ENCODING USING PREDICTED RESIDUALS - An encoder for encoding a video by performing motion estimation using predicted residuals in the rate-distortion cost expression. The predicted residuals are determined by finding a predicted motion vector with respect to the original reference frame and calculating the corresponding residual values. The actual motion vector is then selected based on minimization of the rate-distortion cost expression with respect to the reconstructed reference frame, where the rate-distortion cost expression includes the predicted residuals. In particular, the cost expression includes reconstructed predicted residuals within the distortion term. | 07-14-2011 |

20110170771 | Method, System and Software Product for Color Image Encoding - The present invention relates to the compression of color image data. A combination of hard decision pixel mapping and soft decision pixel mapping is used to jointly address both quantization distortion and compression rate while maintaining low computational complexity and compatibility with standard decoders, such as, for example, the GIF/PNG decoder. | 07-14-2011 |

20110184733 | SYSTEM AND METHOD FOR ENCODING AND DECODING PULSE INDICES - Methods, and corresponding codec-containing devices are provided that have source coding schemes for encoding a component of an excitation. In some cases, the source coding scheme is an enumerative source coding scheme, while in other cases the source coding scheme is an arithmetic source coding scheme. In some cases, the source coding schemes are applied to encode a fixed codebook component of the excitation for a codec employing codebook excited linear prediction, for example an AMR-WB (Adaptive Multi-Rate-Wideband) speech codec. | 07-28-2011 |

20110200101 | METHOD AND ENCODER FOR CONSTRAINED SOFT-DECISION QUANTIZATION IN DATA COMPRESSION - A method of encoding a video using constrained soft-decision quantization. The soft-decision quantization includes first performing hard-decision quantization to obtain hard quantized coefficients and, then, obtaining a soft quantized coefficient using a rate-distortion calculation over a search range of quantization levels for a transform domain coefficient, wherein the search range of quantization levels for that transform domain coefficient is constrained within a number of quantization levels of a corresponding hard quantized coefficient. The search range may be based upon a fixed threshold, the coefficient position, the hard quantized coefficient magnitude, a threshold value less accumulated distortion, or other factors, including combinations of these factors. The accumulated distortion may be measured by an L1 norm. | 08-18-2011 |

20110200104 | PARALLEL ENTROPY CODING AND DECODING METHODS AND DEVICES - A method for entropy coding data using parallel entropy coders to encode an input sequence as a plurality of encoded subsequences, which are then combined to form an output bitstream. The input sequence is separated into subsequences on the basis of a context model. A method for entropy decoding a bitstream of encoded data by extracting a plurality of encoded subsequences from the bitstream and entropy decoding the encoded subsequences in parallel to generate a plurality of decoded subsequences, which are then interleaved based on a context model to produce a reconstructed sequence. | 08-18-2011 |

20110235932 | METHOD AND DEVICE FOR SELECTING OPTIMAL TRANSFORM MATRICES FOR DOWN-SAMPLING DCT IMAGE - Down-sampling of an image may be performed in the DCT domain. Transform matrices are obtained for down-sampling a DCT image of size M×N to a down-sampled DCT image of size I×J. The transform matrices may be used to down-sample the DCT image directly in the DCT domain. A spatial domain down-sampling method is selected and applied to the DCT image to produce a down-sampled DCT reference image. The transform matrices are selected by solving an optimization problem, leading to transform matrices which achieve a desired trade-off between the visual quality of images obtained using the transform matrices and the computational complexity associated with using the transform matrices. The visual quality is a measure of the difference between the down-sampled DCT image obtained using the transform matrices and the visual quality of the DCT reference image obtained using a spatial domain down-sampling method. | 09-29-2011 |

20110248872 | METHODS AND DEVICES FOR LOAD BALANCING IN PARALLEL ENTROPY CODING AND DECODING - Devices and methods for entropy decoding a bitstream of encoded data by extracting a plurality of encoded subsequences from a payload field of the bitstream for parallel decoding on a set of parallel entropy decoders. The method includes dividing the payload of concatenated encoded subsequences into segments using a distribution function and distributing the segments amongst the set of parallel entropy decoders to balance the computational load among the parallel entropy decoders. The received bitstream includes auxiliary information inserted by the encoder to enable the decoder to entropy decode segments that begin with a portion of an encoded subsequence. | 10-13-2011 |

20110249722 | METHOD AND DEVICE FOR SELECTING TRANSFORM MATRICES FOR DOWN-SAMPLING DCT IMAGE USING LEARNING WITH FORGETTING ALGORITHM - Down-sampling of an image may be performed in the DCT domain. A multiple layered network is used to select transform matrices for down-sampling a DCT image of size M×N to a DCT image of size I×J. A spatial domain down-sampling method is selected and applied to the DCT image to produce a down-sampled DCT reference image. A learning with forgetting algorithm is used to apply a decay to the elements of the transform matrix and select a transform matrices which solve an optimization problem. The optimization problem is a function of the visual quality of images obtained using the transform matrices and the computational complexity associated with using the transform matrices. The visual quality is a measure of the difference between the down-sampled DCT image obtained using the transform matrices and the visual quality of the DCT reference image obtained using a spatial domain down-sampling method. | 10-13-2011 |

20110249748 | METHODS AND DEVICES FOR INCORPORATING DEBLOCKING INTO ENCODED VIDEO - Encoders and methods of encoding that incorporate deblocking into the encoding process. An encoder performs a two-cycle encoding process. First, an original block is processed and then reconstructed and deblocked. The reconstruction and the deblocked reconstruction are compared to the original and an intermediate block is created that contains the portions of the reconstruction or the deblocked reconstruction that are more similar to the original. In the second cycle, the intermediate block serves to generate a modified original block, which is then used in a prediction process to create a new prediction block. The new prediction block as compared to the original gives new residuals. The new prediction and new residuals are entropy coded to generate the encoded video data. The new prediction block and new residuals incorporate the deblocking elements selectively identified during the first cycle, thereby eliminating the need for deblocking at the decoder. The prediction operation may be motion prediction or spatial prediction. | 10-13-2011 |

20110251994 | DETERMINATION OF COMPRESSION STATE INFORMATION FOR USE IN INTERACTIVE COMPRESSION - The invention is directed at a method and apparatus for determining compression state information which is to be used in the compression of data being transmitted between two communicating parties. The method of determining the compression state information for use in interactively compressing data comprises the steps parsing the data to determine a hierarchical data structure of the data; traversing a shared hierarchical node index to determine common compression state information entries between the hierarchical data structure and the hierarchical node index; and selecting at least one of the common compression state information entries for use in compressing the data. | 10-13-2011 |

20110279474 | Method, System and Software Product for Color Image Encoding - The present invention relates to the compression of color image data. A combination of hard decision pixel mapping and soft decision pixel mapping is used to jointly address both quantization distortion and compression rate while maintaining low computational complexity and compatibility with standard decoders, such as, for example, the GIF/PNG decoder. | 11-17-2011 |

20120008680 | METHODS AND DEVICES FOR DATA COMPRESSION USING ADAPTIVE RECONSTRUCTION LEVELS - Encoding and decoding methods that perform quantization using adaptive reconstruction levels are presented. The reconstruction levels for a given partitioning of the data space may be selected based upon the distribution of data points within each sub-part defined by the partitioning. In some cases, the adaptive reconstruction levels may be based upon an average of the data points within each sub-part. In some cases, the adaptive reconstruction levels may be selected using a rate-distortion analysis including the quantization distortion associated with the levels versus the data points and the rate associated with transmitting the encoded adaptive reconstruction levels. The methods relate to data compression in a range of applications including audio, images and video. | 01-12-2012 |

20120014435 | Soft Decision and Iterative Video Coding for MPEG and H.264 - A method of encoding video data using soft decision quantization makes use of iterative encoding to provide the ability to optimize encoding across different functional elements in a hybrid video encoder. Iterative encoding is used to allow quantization step size, motion prediction and quantization levels to be optimized despite their interrelated nature. | 01-19-2012 |

20120014615 | METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR OPTIMIZATION OF DATA COMPRESSION - A sequence of n coefficients is compressed by determining a cost-determined sequence of n coefficient indices represented by a cost-determined sequence of (run, index derivative) pairs under a given quantization table and run-index derivative coding distribution, wherein each sequence of (run, index derivative) pairs defines a corresponding sequence of coefficient indices such that (i) each index in the corresponding sequence of coefficient indices is a digital number, (ii) the corresponding sequence of coefficient indices includes a plurality of values including a special value, and (iii) each (run, index derivative) pair defines a run value representing a number of consecutive indices of the special value, and an index-based value derived from a value of the index following the number of consecutive indices of the special value. This involves (a) using the given quantization table and run-index derivative coding distribution to formulate a cost function for a plurality of possible sequences of (run, index derivative) pairs; (b) applying the cost function to each possible sequence in the plurality of possible sequences of (run, index derivative) pairs to determine an associated cost; and, (c) selecting the cost-determined sequence of (run, index derivative) pairs from the plurality of possible sequences of (run, index derivative) pairs based on the associated cost of each of the plurality of possible sequences of (run, index derivative) pairs; and encoding the corresponding selected cost-determined sequence of (run, index derivative) pairs using entropy coding based on a run-index derivative coding distribution. | 01-19-2012 |

20120039530 | METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR PROVIDING ENTROPY CONSTRAINED COLOR SPLITTING FOR PALETTE IMAGES WITH COLOR-WISE SPLITTING - A method, system and computer program product for progressively encoding a digitized color image is provided. This involves: initializing a tree structure with at least one starting leaf node; determining at least one representative color for each starting leaf node; and growing the tree structure by (i) selecting a leaf node n to become a non-leaf node n linked to two new leaf nodes based on an associated achievable cost; (ii) creating the two new leaf nodes by re-allocating each color in n; (iii) determining a representative color for each of the two new leaf nodes; and (iv) encoding the index information associated with the leaf node n, the representative colors of the two new leaf nodes, and information regarding a plurality of pixels of the digitized color image corresponding to the two representative colors of the two new leaf nodes. | 02-16-2012 |

20120039542 | METHOD AND SYSTEM FOR DECODING ENCODED IMAGES AND REDUCING THE SIZE OF SAID IMAGES - A method and system for reducing the number of mathematical operations required in the JPEG decoding process without substantially impacting the quality of the image displayed is disclosed. Embodiments provide an efficient JPEG decoding process for the purposes of displaying an image on a display smaller than the source image, for example, the screen of a handheld device. According to one aspect of the invention, this is accomplished by reducing the amount of processing required for dequantization and inverse DCT (IDCT) by effectively reducing the size of the image in the quantized, DCT domain prior to dequantization and IDCT. This can be done, for example, by discarding unnecessary DCT index rows and columns prior to dequantization and IDCT. In one embodiment, columns from the right, and rows from the bottom are discarded such that only the top left portion of the block of quantized, and DCT coefficients are processed. | 02-16-2012 |

20120044097 | METHOD AND SYSTEM FOR REDUCING CONTEXTS FOR CONTEXT BASED COMPRESSION SYSTEMS - For context based compression techniques, for example Context Based YK compression, a method and system for grouping contexts from a given context model together to create a new context model that has fewer contexts, but retains acceptable compression gains compared to the original context model. According to an exemplary embodiment of the method empirical statistics are determined for a file type of a file to be compressed; and the context model is generated by iteratively grouping contexts of an initial context model in accordance with the empirical statistics, the context model having fewer contexts than an initial context model. | 02-23-2012 |

20120047171 | SYNCHRONIZATION OF SIDE INFORMATION CACHES - In order to improve interactive compression using compression state information, the side information caches of communicating parties must be updated, or synchronized. The present invention is directed to a method of synchronizing side information databases within an interactive compression system comprising two communicating parties comprising the steps of transmitting, from the a first communicating party to the second communicating party, a device hierarchical node index; comparing the device hierarchical node index with a server hierarchical node index and then determining a shared hierarchical node index based on common entries in the two hierarchical node indexes. | 02-23-2012 |

20120072613 | INTERACTIVE COMPRESSION WITH MULTIPLE UNITS OF COMPRESSION STATE INFORMATION - There is provided a method of interactive compression using multiple compression state information entries. The method comprises receiving a request for data from a communicating party; retrieving the data; identifying, for use in compressing the data, at least two compression state information entries shared between the parties to the communication; compressing the data with each of the at least two compression state information entries; determining, from the set of compression state information entries, a preferred compression state information entry that provides a greatest compression ratio; and transmitting the data, compressed in accordance with the preferred compression state information entry to the communicating party. | 03-22-2012 |

20120093220 | IN-LOOP DEBLOCKING FOR INTRA-CODED IMAGES OR FRAMES - Methods and encoders/decoders for applying in-loop deblocking to intra-coded images/frames. In a decoding context, a deblocking filter is applied to reconstructed pixels of an intra-coded block prior to decoding the subsequent block in the decoding sequence. In an encoding context, a deblocking filter is applied to reconstructed pixels of an intra-coded block in an inter-coding loop before encoding a subsequent block in the coding order for the image. | 04-19-2012 |

20120093428 | METHOD AND DEVICE FOR DOWN-SAMPLING A DCT IMAGE IN THE DCT DOMAIN - A method and device that uses transform matrices to down-sample a DCT image directly in the DCT domain. The transform matrices have been selected to minimize an optimization problem which is a function of the visual quality of down-sampled images obtained using the matrices and the computational complexity associated with using the transform matrices. The transform matrices comprise a row transform matrix and a column transform matrix. A down-sampled image is produced by determining an intermediary matrix as the product of the DCT image and one of either the row transform matrix or the column transform matrix and then determining the down-sampled image as the product of the intermediary matrix and the transform matrix not already used to determine the intermediary matrix. | 04-19-2012 |

20120194363 | METHODS AND DEVICES FOR LOAD BALANCING IN PARALLEL ENTROPY CODING AND DECODING - Devices and methods for entropy decoding a bitstream of encoded data by extracting a plurality of encoded subsequences from a payload field of the bitstream for parallel decoding on a set of parallel entropy decoders. The method includes dividing the payload of concatenated encoded subsequences into segments using a distribution function and distributing the segments amongst the set of parallel entropy decoders to balance the computational load among the parallel entropy decoders. The received bitstream includes auxiliary information inserted by the encoder to enable the decoder to entropy decode segments that begin with a portion of an encoded subsequence. | 08-02-2012 |

20120213298 | METHOD AND SYSTEM FOR OPTIMIZING QUANTIZATION FOR NOISY CHANNELS - Methods are described for configuring a quantizer to achieve improved end-to-end distortion performance when transmitting encoded source data over a noisy channel. The codebook and partitioning are selected using an iterative process of determining an updated codebook and an updated partition space, where the updated codebook is based, in part, on the average symbol error probability of the channel. Complete knowledge of the transitional probabilities of the channel is not required. Variants of the iterative process are described. | 08-23-2012 |

20120219055 | METHODS AND DEVICES FOR DATA COMPRESSION USING OFFSET-BASED ADAPTIVE RECONSTRUCTION LEVELS - Encoding and decoding methods are presented that used offset-based adaptive reconstruction levels. The offset data is inserted in the bitstream with the encoded video data. The offset data may be differential data and may be an index to an array of offset values from which the differential offset is calculated by the decoder. The offset to an adaptive reconstruction level may be adjusted for each slice. The offsets may be specific to a particular level/index and data type. In some cases, offsets may only be sent for a subset of the levels. Higher levels may apply no offset, may apply an average offset, or may apply the offset used for the highest level having a level-specific offset. | 08-30-2012 |

20120224780 | METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR OPTIMIZATION OF DATA COMPRESSION WITH ITERATIVE COST FUNCTION - A method, system and computer software product for improving rate-distortion performance while remaining faithful to JPEG/MPEG syntax, involving joint optimization of Huffman tables, quantization step sizes and quantized coefficients of a JPEG/MPEG encoder. This involves finding the optimal coefficient indices in the form of (run, size) pairs. By employing an interative process including this search for optimal coefficient indices, joint improvement of run-length coding, Huffman coding and quantization table selection may be achieved. Additionally, the compression of quantized DC coefficients may also be improved using a trellis-structure. | 09-06-2012 |

20120232911 | OPTIMIZATION OF MP3 AUDIO ENCODING BY SCALE FACTORS AND GLOBAL QUANTIZATION STEP SIZE - An iterative rate-distortion optimization algorithm for MPEG I/II Layer-3 (MP3) encoding based on the method of Lagrangian multipliers. Generally, an iterative method is performed such that a global quantization step size is determined while scale factors are fixed, and thereafter the scale factors are determined while the global quantization step size is fixed. This is repeated until a calculated rate-distortion cost is within a predetermined threshold. The methods are demonstrated to be computationally efficient and the resulting bit stream is fully standard compatible. | 09-13-2012 |

20120263375 | METHOD AND DEVICE FOR SELECTING OPTIMAL TRANSFORM MATRICES FOR DOWN-SAMPLING DCT IMAGE - Down-sampling of an image may be performed in the DCT domain. Transform matrices are obtained for down-sampling a DCT image of size M×N to a down-sampled DCT image of size I×J. The transform matrices may be used to down-sample the DCT image directly in the DCT domain. A spatial domain down-sampling method is selected and applied to the DCT image to produce a down-sampled DCT reference image. The transform matrices are selected by solving an optimization problem, leading to transform matrices which achieve a desired trade-off between the visual quality of images obtained using the transform matrices and the computational complexity associated with using the transform matrices. The visual quality is a measure of the difference between the down-sampled DCT image obtained using the transform matrices and the visual quality of the DCT reference image obtained using a spatial domain down-sampling method. | 10-18-2012 |

20120263392 | ARBITRARY RATIO IMAGE RESIZING IN THE DCT DOMAIN - To resize a compressed image, first and second scaling parameters P and Q are determined in accordance with the block numbers L and M and the scaling ratio L/M or M/L. A non-uniform, or uneven, sampling in the DCT domain is then applied to coefficients of successive blocks in the compressed image in accordance with the scaling parameters. In an embodiment, P blocks are sampled and transformed from a given block length to |P| according to a |P|-point IDCT, while Q blocks are sampled and transformed from a given block length to |Q| according to a |Q|-point IDCT. The non-uniformly sampled and transformed pixel domain samples are then regrouped into a predetermined block size and transformed back to generate the DCT coefficient of the compressed image. The proposed method significantly reduces the computational complexity compared with other DCT domain arbitrary ratio image resizing approach. | 10-18-2012 |

20120301022 | Method, System and Software Product for Color Image Encoding - The present invention relates to the compression of color image data. A combination of hard decision pixel mapping and soft decision pixel mapping is used to jointly address both quantization distortion and compression rate while maintaining low computational complexity and compatibility with standard decoders, such as, for example, the GIF/PNG decoder. | 11-29-2012 |

20140307781 | METHODS AND DEVICES FOR DATA COMPRESSION USING OFFSET-BASED ADAPTIVE RECONSTRUCTION LEVELS - Encoding and decoding methods are presented that used offset-based adaptive reconstruction levels. The offset data is inserted in the bitstream with the encoded video data. The offset data may be differential data and may be an index to an array of offset values from which the differential offset is calculated by the decoder. The offset to an adaptive reconstruction level may be adjusted for each slice. The offsets may be specific to a particular level/index and data type. In some cases, offsets may only be sent for a subset of the levels. Higher levels may apply no offset, may apply an average offset, or may apply the offset used for the highest level having a level-specific offset. | 10-16-2014 |

20140317068 | 10-23-2014 |