# Xiang Yu, Kitchener CA

## Xiang Yu, Kitchener CA

Patent application number | Description | Published |
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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 |

20110170595 | METHOD AND DEVICE FOR MOTION VECTOR PREDICTION IN VIDEO TRANSCODING USING FULL RESOLUTION RESIDUALS - A transcoder and methods of encoding inter-prediction frames of a downsampled video wherein the downsampled video is a spatially downsampled version of a full-resolution video. Full-resolution motion vectors are downscaled and a weighting factor is calculated for each downscaled motion vector based upon the transform domain residual coefficients associated with that full-resolution motion vector. A motion vector prediction is made based on the weighted average using the downscaled motion vectors and their weighting factors. | 07-14-2011 |

20110170596 | METHOD AND DEVICE FOR MOTION VECTOR ESTIMATION IN VIDEO TRANSCODING USING UNION OF SEARCH AREAS - A transcoder and methods of encoding inter-prediction frames of a downsampled video wherein the downsampled video is a spatially downsampled version of a full-resolution video. Full-resolution motion vectors are downscaled and each downscaled motion vector pinpoints a search area within a reference frame. The union or combination of search areas defines the search field for candidate motion vectors. A motion vector is selected from the candidates based on realizing a minimum rate-distortion cost. | 07-14-2011 |

20110170597 | METHOD AND DEVICE FOR MOTION VECTOR ESTIMATION IN VIDEO TRANSCODING USING FULL-RESOLUTION RESIDUALS - A transcoder and method of transcoding in which inter-prediction frames of a downsampled video are encoded using downsampled full-resolution residuals in the rate-distortion analysis used to locate a motion vector for a given partition in the downsampled video. | 07-14-2011 |

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 |

20110170608 | METHOD AND DEVICE FOR VIDEO TRANSCODING USING QUAD-TREE BASED MODE SELECTION - An encoder for encoding a downsampled video in which macroblock partitioning is based upon downsampled partitioning of full-resolution macroblocks. The refinement of the downsampled partitioning involves storing the downsampled partitioning in a quad-tree data structure and recursively identifying and evaluating possible mergers of leaf nodes having a common parent node. Using rate-distortion analysis possible mergers are evaluated and advantageous mergers are performed, thereby creating larger partitions and new leaf nodes. The traversing of the quad-tree to identify possible leaf node mergers is stopped when no further possible mergers may be identified that would result in a rate-distortion advantage. | 07-14-2011 |

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 |

20120063691 | METHODS AND DEVICES FOR DATA COMPRESSION WITH ADAPTIVE FILTERING IN THE TRANSFORM DOMAIN - Methods and devices for encoding and decoding data using adaptive transform domain filtering are described. The encoder determines a set of transform domain filter coefficients to be applied to a transform domain prediction. The filtering may, in some cases, also apply to quantized transform domain coefficients. Rate-distortion optimization may be used to determine the optimal filter coefficients on a frame-based, coding-unit-basis, or other basis. | 03-15-2012 |

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 |

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 |

20120328001 | COMPRESSING IMAGE DATA - Methods, systems, and computer programs for encoding and decoding image are described. In some aspects, an input data block and a prediction data block are accessed. A projection factor is generated based on a projection of the input data block onto the prediction data block. A scaled prediction data block is generated by multiplying the projection factor by the prediction data block. A residual data block is generated based on a difference between the input data block and the scaled prediction data block. In some aspects, a prediction data block, a residual data block, and a projection factor associated with the residual data block are accessed. A scaled prediction data block is generated by multiplying the projection factor by the prediction data block. An output data block is generated by summing the residual data block and the scaled prediction data block. | 12-27-2012 |

20120328183 | 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. | 12-27-2012 |

20120328204 | COMPRESSING IMAGE DATA - Methods, systems, and computer programs for encoding and decoding image are described. In some aspects, an input data block and a prediction data block are accessed. A projection factor is generated based on a projection of the input data block onto the prediction data block. A scaled prediction data block is generated by multiplying the projection factor by the prediction data block. A residual data block is generated based on a difference between the input data block and the scaled prediction data block. In some aspects, a prediction data block, a residual data block, and a projection factor associated with the residual data block are accessed. A scaled prediction data block is generated by multiplying the projection factor by the prediction data block. An output data block is generated by summing the residual data block and the scaled prediction data block. | 12-27-2012 |

20130083845 | METHODS AND DEVICES FOR DATA COMPRESSION USING A NON-UNIFORM RECONSTRUCTION SPACE - Encoding and decoding methods are presented that use adaptive reconstruction levels. Reconstruction space parameters are developed by an encoder and inserted in the bitstream with the encoded video data. The reconstruction space parameter may include parameters from which the decoder can determine the levels for dequantization of the encoded video data. The reconstruction space parameters may include a first reconstruction level and a step size between other levels. The first reconstruction level may not equal the step size. In some cases, neither may be equal to the quantization step size used to quantize the transform domain coefficients. | 04-04-2013 |

20130129241 | METHODS AND DEVICES FOR ENCODING AND DECODING TRANSFORM DOMAIN FILTERS - Methods and devices for encoding and decoding data using transform domain filtering are described. The encoder determines a set of transform domain filter coefficients to be applied to a transform domain prediction. The filtering may, in some cases, also apply to transform domain reconstructions. Rate-distortion optimization may be used to determine the optimal filter coefficients on a frame-basis, coding-unit-basis, or other basis. Multiple filters may be developed and communicated from the encoder to the decoder for different combinations of transform block size, coding mode, prediction mode, and texture type. In other cases, the filtering is applied in the pixel-domain to a pixel-domain prediction or a pixel-domain reconstruction of a block of samples. | 05-23-2013 |

20130188725 | MULTIPLE SIGN BIT HIDING WITHIN A TRANSFORM UNIT - Methods of encoding and decoding for video data are described for encoding or decoding coefficients for a transform unit. In particular, the sign bits for the non-zero coefficients are encoded using sign bit hiding. Two or more sets of coefficients are defined for the transform unit and a sign bit may be hidden for each set, subject to satisfaction of a threshold test. The sets may correspond to coefficient groups that are otherwise used in multi-level significance map encoding and decoding. | 07-25-2013 |

20130235936 | MOTION VECTOR SIGN BIT HIDING - Methods of encoding and decoding for video data for encoding or decoding motion vector difference components for inter-coded video are described. The sign of one of the components is hidden within the parity of the sum of the magnitudes of the horizontal and vertical difference components. The sign of the other of the components is explicitly signaled in the bitstream. The hidden sign may be assigned to the larger in magnitude of the two components. In other cases, the hidden sign may always be assigned to the horizontal or vertical component. In another case, the hidden sign may always be assigned to one component, unless that component is zero, in which case the hidden sign is assigned to the other component. In another case, both components may have their signs hidden, in which case the sign hiding is based on their respective parity, rather than the parity of their sum. | 09-12-2013 |

20130272384 | MODIFIED CONTEXTS FOR LEVEL CODING OF VIDEO DATA - Methods and devices for reconstructing coefficient levels from a bitstream of encoded video data for a coefficient group in a transform unit, and corresponding methods and devices for encoding are provided. The method of reconstructing includes, for each of the non-zero coefficients in the coefficient group, in scan order, decoding a greater-than-one flag for that non-zero coefficient if fewer than two previously-decoded greater-than-one flags for that coefficient group are equal to one. The coefficient levels for the non-zero coefficients are reconstructed based, at least in part, upon the decoded greater-than-one flags. | 10-17-2013 |

20130336409 | MULTI-BIT INFORMATION HIDING USING OVERLAPPING SUBSETS - Methods and devices for reconstructing coefficient levels from a bitstream of encoded video data for a coefficient group in a transform unit. Sign bits are hidden in the parity of partially overlapping subsets of a set of coefficients. This enables the hiding of multiple sign bits per coefficient group. Other information bits may be hidden instead of sign bits in some cases. | 12-19-2013 |

20140003488 | POSITION-BASED CONTEXT SELECTION FOR GREATER-THAN-ONE FLAG DECODING AND ENCODING | 01-02-2014 |

20140010288 | 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. | 01-09-2014 |

20140064364 | METHODS AND DEVICES FOR INTER-LAYER PREDICTION IN SCALABLE VIDEO COMPRESSION - Methods and devices for encoding and decoding scalable video are described. In one aspect, a method of reconstructing, in a video decoder, an enhancement-layer image based upon a reconstructed reference-layer image using inter-layer prediction is described. The method includes reconstructing a reference-layer residual and a reference-layer prediction, wherein the reference-layer residual and the reference-layer prediction, when combined, form the reconstructed reference-layer image; up-sampling the reference-layer residual using a first up-sampling operation; up-sampling the reference-layer prediction using a second up-sampling operation different from the first up-sampling operation; generating an inter-layer prediction using the up-sampled reference-layer residual and the up-sampled reference-layer prediction; and reconstructing the enhancement-layer image based upon the inter-layer prediction. | 03-06-2014 |

20140064365 | METHODS AND DEVICES FOR ENTROPY CODING IN SCALABLE VIDEO COMPRESSION - Methods and devices for decoding, in a video decoder, a block of enhancement-layer transform domain data for an enhancement-layer encoded video and corresponding to a reconstructed block of reference-layer transform domain data, are provided. The method includes determining a context for an enhancement-layer element based, at least in part, upon elements in the corresponding reconstructed block of reference-layer transform domain data, wherein the elements are identified by a template and wherein the position of the template in the reference-layer reconstructed block is based upon the position of that enhancement-layer element in the block of enhancement-layer transform domain data. | 03-06-2014 |

20140286405 | Compressing Image Data - Methods, systems, and computer programs for encoding and decoding image are described. In some aspects, an input data block and a prediction data block are accessed. A projection factor is generated based on a projection of the input data block onto the prediction data block. A scaled prediction data block is generated by multiplying the projection factor by the prediction data block. A residual data block is generated based on a difference between the input data block and the scaled prediction data block. In some aspects, a prediction data block, a residual data block, and a projection factor associated with the residual data block are accessed. A scaled prediction data block is generated by multiplying the projection factor by the prediction data block. An output data block is generated by summing the residual data block and the scaled prediction data block. | 09-25-2014 |

20140348438 | SYSTEM AND METHOD HAVING TRANSPARENT COMPOSITE MODEL FOR TRANSFORM COEFFICIENTS - To better handle the flat tail phenomenon commonly seen in transform coefficients such as DCT coefficients, a system and method having a model dubbed a transparent composite model (TCM) are described. Given a sequence of transform coefficients, a TCM first separates the tail of the sequence from the main body of the sequence. A first distribution such as a uniform, truncated Laplacian, or truncated geometric distribution can be used to model transform coefficients in the flat tail while at least one parametric distribution (e.g. truncated Laplacian, generalized Gaussian (GG), and geometric distributions) can be used to model data in the main body. A plurality of boundary values can be used to bound a plurality of distribution models. The plurality of boundary values and other parameters of the TCM can be estimated via maximum likelihood (ML) estimation or greedy estimation. | 11-27-2014 |

20140355674 | Compressing Image Data - Methods, systems, and computer programs for encoding and decoding image are described. In some aspects, an input data block and a prediction data block are accessed. A projection factor is generated based on a projection of the input data block onto the prediction data block. A scaled prediction data block is generated by multiplying the projection factor by the prediction data block. A residual data block is generated based on a difference between the input data block and the scaled prediction data block. In some aspects, a prediction data block, a residual data block, and a projection factor associated with the residual data block are accessed. A scaled prediction data block is generated by multiplying the projection factor by the prediction data block. An output data block is generated by summing the residual data block and the scaled prediction data block. | 12-04-2014 |