Patent application number | Description | Published |
20080224905 | DATA COMPRESSION USING VARIABLE-TO-FIXED LENGTH CODES - This disclosure is directed to techniques for memory efficient variable to fixed length (VF) coding techniques for a variety of applications, such as media coding. For example, such techniques may be applied to code digital video, image, audio, or speech data. The techniques described in this disclosure may utilize algebraic properties of VF coding trees constructed using Tunstall or Khodak algorithms, and employ combinatorial enumeration techniques for construction, encoding and decoding of codewords. For some applications, the VF coding techniques may be implemented within media encoders, decoders, or combined encoder-decoders (CODECs). Also, in some aspects, various attributes defining a VF coding tree constructed according to this disclosure may be provided in a memory efficient data structure stored in memory associated with a coding device. | 09-18-2008 |
20090063599 | FAST COMPUTATION OF PRODUCTS BY DYADIC FRACTIONS WITH SIGN-SYMMETRIC ROUNDING ERRORS - A product of an integer value and an irrational value may be determined by a sign-symmetric algorithm. A process may determine possible algorithms that minimize metrics such as mean asymmetry, mean error, variance of error, and magnitude of error. Given an integer variable x and rational dyadic constants that approximate the irrational fraction, a series of intermediate values may be produced that are sign-symmetric. The intermediate values may include a sequence of addition, subtraction and right shift operations the when summed together approximate the product of the integer and irrational value. Other operations, such as additions or subtractions of 0s or shifts by 0 bits may be removed. | 03-05-2009 |
20090094038 | EFFICIENT DESIGN OF MDCT / IMDCT FILTERBANKS FOR SPEECH AND AUDIO CODING APPLICATIONS - A more efficient encoder/decoder is provided in which an N-point MDCT transform is mapped into smaller sized N/2-point DCT-IV and/or DCT-II transforms with isolated pre-multiplications which can be moved to a prior or subsequent windowing stage. That is, the windowing operations may be merged with first/last stage multiplications in the core MDCT/IMDCT functions, respectively, thus reducing the total number of multiplications. Additionally, the MDCT may be systematically decimated by factor of 2 by utilizing a uniformly scaled 5-point DCT-II core function as opposed to the DCT-IV or FFT cores used in many existing MDCT designs in audio codecs. The modified windowing stage merges factors from a transform stage and windowing stage to obtain piece-wise symmetric windowing factors, which can be represented by a sub-set of the piece-wise symmetric windowing factors to save storage space. Such features offer appreciable reduction in complexity and less memory usage than the prior art. | 04-09-2009 |
20090099844 | EFFICIENT IMPLEMENTATION OF ANALYSIS AND SYNTHESIS FILTERBANKS FOR MPEG AAC AND MPEG AAC ELD ENCODERS/DECODERS - An encoder may include a core MDCT filterbank that can be used to implement an advanced audio coding (AAC) algorithm, an AAC-enhanced low delay (ELD) algorithm or both algorithms. For the AAC algorithm, a sequence of input samples is sent directly to the MDCT filterbank to obtain a sequence of output samples. For the AAC-ELD algorithm, the signs of input samples of the sequence of input samples are inverted, the MDCT analysis filterbank is applied to the sign-inverted sequence of input samples to obtain a sequence of output samples, the order of the sequence of output samples is reversed, and the signs of alternating output samples of the sequence of output samples are inverted. Similarly, a decoder may include a core IMDCT synthesis filterbank that can be used to implement AAC-ELD or both AAC and AAC-ELD algorithms. The steps for the decoder are merely the reverse of the encoder. | 04-16-2009 |
20090153907 | EFFICIENT DIFFUSION DITHERING USING DYADIC RATIONALS - Diffusion dithering can be performed efficiently by applying a set of diffusion filter weights with one or more shift, add, and/or subtract operations. An existing diffusion filter can be approximated with dyadic rationals, thereby allowing division operations in applying the filter weights to be performed with bit-shifting operations. An algorithm is identified to calculate the product of a set of filter weights and a pixel error, where the algorithm performs the calculations using one or more shift, add, or subtract operations. An exhaustive search of the combinations of operations can be made to find an efficient algorithm to calculate the products | 06-18-2009 |
20090157785 | FAST ALGORITHMS FOR COMPUTATION OF 5-POINT DCT-II, DCT-IV, AND DST-IV, AND ARCHITECTURES - A more efficient encoder/decoder is provided in which an N-point MDCT transform is mapped into smaller sized N/2-point DCT-IV, DST-IV and/or DCT-II transforms. The MDCT may be systematically decimated by factor of 2 by utilizing a uniformly scaled 5-point DCT-II core function as opposed to the DCT-IV or FFT cores used in many existing MDCT designs in audio codecs. Various transform factorizations of the 5-point transforms may be implemented to more efficiently implement a transform. | 06-18-2009 |
20090234644 | Low-complexity encoding/decoding of quantized MDCT spectrum in scalable speech and audio codecs - A scalable speech and audio codec is provided that implements combinatorial spectrum encoding. A residual signal is obtained from a Code Excited Linear Prediction (CELP)-based encoding layer, where the residual signal is a difference between an original audio signal and a reconstructed version of the original audio signal. The residual signal is transformed at a Discrete Cosine Transform (DCT)-type transform layer to obtain a corresponding transform spectrum having a plurality of spectral lines. The transform spectrum spectral lines are transformed using a combinatorial position coding technique. | 09-17-2009 |
20100172409 | LOW-COMPLEXITY TRANSFORMS FOR DATA COMPRESSION AND DECOMPRESSION - This disclosure describes the use of non-dyadic discrete cosine transform (DCT) sizes for performing a DCT. Similarly, this disclosure describes the use of non-dyadic inverse discrete cosine transform (IDCT) sizes for performing an IDCT. Using non-dyadic transform sizes may be less computationally expensive compared to using conventional dyadic transform sizes. Aspects of this disclosure may be useful in any device or system that performs a DCT or IDCT. | 07-08-2010 |
20100191534 | METHOD AND APPARATUS FOR COMPRESSION OR DECOMPRESSION OF DIGITAL SIGNALS - The subject matter disclosed herein relates generally to a system and method for linear prediction of sample values. | 07-29-2010 |
20100303354 | EFFICIENT CODING OF PROBABILITY DISTRIBUTIONS FOR IMAGE FEATURE DESCRIPTORS - A method for encoding or compressing probability distributions is disclosed. A first mapping of probability distribution of samples to the types from the predefined set of types is generated. A second mapping of the types in the predefined set of types to lexicographic indexes from the index space is generated. A probability distribution is quantized as a type from the predefined set of types. The type is then mapped to a lexicographic index from the index space that spans the predefined set of types. A code for the lexicographic index is then transmitted and/or stored as part of a feature descriptor. | 12-02-2010 |
20100310174 | EFFICIENT INCREMENTAL CODING OF PROBABILITY DISTRIBUTIONS FOR IMAGE FEATURE DESCRIPTORS - A method and device for incremental encoding of a type of a sequence is provided. A sequence of symbols is obtained where each symbol is defined within a set of symbols. The type of sequence may be, for example, an empirical probability distribution of symbols in a sequence of symbols. Each obtained symbol may be identified in the sequence. Each symbol in the sequence of symbols is then arithmetically coded using only previous occurrences of the same symbol in the sequence of symbols as a context to generate an incremental code. The incremental codes for the symbols in the set of symbols are then concatenated or combined to generate a complete code representative of the type of the sequence of symbols. | 12-09-2010 |
20110299770 | PERFORMANCE OF IMAGE RECOGNITION ALGORITHMS BY PRUNING FEATURES, IMAGE SCALING, AND SPATIALLY CONSTRAINED FEATURE MATCHING - A method for feature matching in image recognition is provided. First, image scaling may be based on a feature distribution across scale spaces for an image to estimate image size/resolution, where peak(s) in the keypoint distribution at different scales is used to track a dominant image scale and roughly track object sizes. Second, instead of using all detected features in an image for feature matching, keypoints may be pruned based on cluster density and/or the scale level in which the keypoints are detected. Keypoints falling within high-density clusters may be preferred over features falling within lower density clusters for purposes of feature matching. Third, inlier-to-outlier keypoint ratios are increased by spatially constraining keypoints into clusters in order to reduce or avoid geometric consistency checking for the image. | 12-08-2011 |
20110299782 | FAST SUBSPACE PROJECTION OF DESCRIPTOR PATCHES FOR IMAGE RECOGNITION - A method for generating a feature descriptor is provided. A set of pre-generated sparse projection vectors is obtained. A scale space for an image is also obtained, where the scale space having a plurality scale levels. A descriptor for a keypoint in the scale space is then generated based on a combination of the sparse projection vectors and sparsely sampled pixel information for a plurality of pixels across the plurality of scale levels. | 12-08-2011 |
20120162732 | DEVICE AND METHOD FOR A HOLOGRAPHIC DISPLAY WITH ELECTROMECHANICAL ACTUATED MIRROR DISPLAY - The present disclosure provides systems, methods and apparatus for producing holographic displays using an electromechanical systems device. In one aspect, the method can be implemented to allow for simultaneous modulation of phase and amplitude of light in a display device composed of a plurality of pixels. A light source can provide sufficiently coherent light to a light guide, which can direct the light to a plurality of reflective members. The reflective members can reflect the light to a pinhole-lenslet array. The combination of the pinhole-lenslet array and the reflective members can act as a spatial light modulator, modulating the phase and amplitude of the light reflected by the reflective members. The lenslet can focus the light to a plane at the opening of the pinhole, wherein the light can exit the pinhole to be viewed in combination with light from additional pixels, and can be viewed as a holographic image. | 06-28-2012 |
20120307893 | FAST COMPUTING OF DISCRETE COSINE AND SINE TRANSFORMS OF TYPES VI AND VII - This disclosure presents techniques for implementing a fast algorithm for implementing odd-type DCTs and DSTs. The techniques include the computation of an odd-type transform on any real-valued sequence of data (e.g., residual values in a video coding process or a block of pixel values of an image coding process) by mapping the odd-type transform to a discrete Fourier transform (DFT). The techniques include a mapping between the real-valued data sequence to an intermediate sequence to be used as an input to a DFT. Using this intermediate sequence, an odd-type transform may be achieved by calculating a DFT of odd size. Fast algorithms for a DFT may be then be used, and as such, the odd-type transform may be calculated in a fast manner | 12-06-2012 |
20130121406 | 8-POINT TRANSFORM FOR MEDIA DATA CODING - In general, techniques are described for implementing an 8-point discrete cosine transform (DCT). An apparatus comprising an 8-point discrete cosine transform (DCT) hardware unit may implement these techniques to transform media data from a spatial domain to a frequency domain. The 8-point DCT hardware unit includes an even portion comprising factors A, B that are related to a first scaled factor (μ) in accordance with a first relationship. The 8-point DCT hardware unit also includes an odd portion comprising third, fourth, fifth and sixth internal factors (G, D, E, Z) that are related to a second scaled factor (η) in accordance with a second relationship. The first relationship relates the first scaled factor to the first and second internal factors. The second relationship relates the second scaled factor to the third internal factor and a fourth internal factor, as well as, the fifth internal factor and a sixth internal factor. | 05-16-2013 |
20130148718 | 8-POINT TRANSFORM FOR MEDIA DATA CODING - In general, techniques are described for implementing an 8-point inverse discrete cosine transform (IDCT). An apparatus comprising an 8-point inverse discrete cosine transform (IDCT) hardware unit may implement these techniques to transform media data from a frequency domain to a spatial domain. The 8-point IDCT hardware unit includes an even portion comprising factors A, B that are related to a first scaled factor (μ) in accordance with a first relationship. The 8-point IDCT hardware unit also includes an odd portion comprising third, fourth, fifth and sixth internal factors (G, D, E, Z) that are related to a second scaled factor (η) in accordance with a second relationship. The first relationship relates the first scaled factor to the first and second internal factors. The second relationship relates the second scaled factor to the third, fourth, fifth and sixth internal factors. | 06-13-2013 |
20130195204 | Methods and Systems for Video Delivery Supporting Adaptation to Viewing Conditions - Described herein are methods and systems associated with viewing condition adaption of multimedia content. A method for receiving multimedia content with a device from a network may include determining a viewing parameter, transmitting a request for the multimedia content to the network, whereby the request may be based on the viewing parameter, and receiving the multimedia content from the network, whereby the multimedia content may be processed at a rate according to the viewing parameter. The viewing parameter may include at least one of: a user viewing parameter, a device viewing parameter, or a content viewing parameter. The method may further include receiving a multimedia presentation description (MPD) file from the network. The MPD file may include information relating to the rate of the multimedia content and information relating to the rate may include a descriptor relating to the viewing parameter, whereby the descriptor may be required or optional. | 08-01-2013 |
20130279606 | SYSTEM AND METHOD FOR ERROR-RESILIENT VIDEO CODING - Error resilient video coding schemes that may be employed at a transmitter or transcoder to limit error propagation at the receiver. Embodiments may include the use of Inhomogeneous Temporal Multiple Description Coding (ITMDC), cross-description error concealment, and cross-description reference picture reset (RPS) as well as homogeneous and inhomogeneous temporal/spatial MDC. | 10-24-2013 |
20130282917 | METHOD AND APPARATUS FOR SMOOTH STREAM SWITCHING IN MPEG/3GPP-DASH - A method and apparatus for providing smooth stream switching in video and/or audio encoding and decoding may be provided. Smooth stream switching may include the generation and/or display of one or more transition frames that may be utilized between streams of media content encoded at different rates. The transition frames may be generated via crossfading and overlapping, crossfading and transcoding, post-processing techniques using filtering, post-processing techniques using re-quantization, etc. Smooth stream switching may include receiving a first data stream of media content characterized by a first signal-to-noise ratio (SNR) and a second data stream of the media content characterized by a second SNR. Transition frames may be generated using at least one of frames of the first data stream and frames of the second data stream. The transition frames may be characterized by one or more SNR values that are between the first SNR and the second SNR. | 10-24-2013 |
20140019593 | QUALITY-DRIVEN STREAMING - Quality-based optimizations of a delivery process of streaming content may be enabled. The optimization may take the form of quality-based switching. To enable quality-based switching in a streaming client, the client may have access to information about the quality of an encoded segment and/or sub-segment. Quality-related information may include any number of added quality metrics relating to an encoded segment and/or sub-segment of an encoded video stream. The addition of quality-related information may be accomplished by including the quality-related information in a manifest file, including the quality-related information in segment indices stored in a segment index file, and/or providing additional files with quality-related segment information and providing a link to the information from an MPD file. Upon receiving the quality-related information, the client may request and receive a stream that has a lower bitrate, thereby saving bandwidth while retaining quality of the streaming content. | 01-16-2014 |
20140019635 | OPERATION AND ARCHITECTURE FOR DASH STREAMING CLIENTS - An adaptive HTTP streaming client may prevent network-level transcoding, may detect that transcoding takes place and implement a custom reaction, and/or may adopt rate estimation and stream switching logic, which may produce meaningful decisions in the presence of caching and transcoding operations in the network. A streaming client may use hash values of received segments, attributes of a received stream of content, and/or segment length checks of representations of segments to determine if the segments were transcoded. A streaming client may use random split range-based HTTP GET requests to deter transcoding. A streaming client may use split range-based HTTP GET requests to improve the accuracy of its bandwidth estimation. A streaming client may use any combination of the techniques described herein to detect transcoding, deter transcoding, adopt improved bandwidth and/or bitrate estimation, and adopt improved switching logic. | 01-16-2014 |
20140036343 | INTERFEROMETRIC MODULATOR WITH IMPROVED PRIMARY COLORS - This disclosure provides systems, methods and apparatus related to an electromechanical display device. In one aspect, an analog interferometric modulator includes a display pixel having a movable reflector, and a movable absorbing layer. The movable absorbing layer is positionable at a variable first distance from an electrode that is substantially transparent over a visible wavelength spectrum. The movable reflector is positionable at a variable second distance from the movable absorbing layer. Changing the first distance and the second distance changes a characteristic of light reflected from the display element. | 02-06-2014 |
20140036667 | Rate Adaptation Using Network Signaling - Systems, methods, and instrumentalities are disclosed to perform rate adaptation in a wireless transmit/receive unit (WTRU). The WTRU may receive an encoded data stream, which may be encoded according to a Dynamic Adaptive HTTP Streaming (DASH) standard. The WTRU may request and/or receive the data stream from a content server. The WTRU may monitor and/or receive a cross-layer parameter, such as a physical layer parameter, a RRC layer parameter, and/or a MAC layer parameter (e.g., a CQI, a PRB allocation, a MRM, or the like). The WTRU may perform rate adaption based on the cross-layer parameter. For example, the WTRU may set the CE bit of an Explicit Congestion Notification (ECN) field based on the cross-layer parameter. The WTRU may determine to request the data stream encoded at a different rate based on the cross-layer parameter, the CE bit, and/or a prediction based on the cross-layer parameter. | 02-06-2014 |
20140149478 | TRANSFORM DESIGN WITH SCALED AND NON-SCALED INTERFACES - Techniques for efficiently performing full and scaled transforms on data received via full and scaled interfaces, respectively, are described and comprise (1) performing a first transform on a block of first input values to obtain a block of first output values by scaling the block to obtain scaled input values, performing a scaled one-dimensional (1D) transform on each row of the block, and performing a scaled 1D transform on each column of the block; and (2) performing a second transform on a block of second input values to obtain a block of second output values by performing a scaled 1D transform on each row of the block, performing a scaled 1D transform on each column of the block, and scaling the block. | 05-29-2014 |
20140330878 | FAST COMPUTATION OF PRODUCTS BY DYADIC FRACTIONS WITH SIGN-SYMMETRIC ROUNDING ERRORS - A product of an integer value and an irrational value may be determined by a sign-symmetric algorithm. A process may determine possible algorithms that minimize metrics such as mean asymmetry, mean error, variance of error, and magnitude of error. Given an integer variable x and rational dyadic constants that approximate the irrational fraction, a series of intermediate values may be produced that are sign-symmetric. The intermediate values may include a sequence of addition, subtraction and right shift operations the when summed together approximate the product of the integer and irrational value. Other operations, such as additions or subtractions of 0s or shifts by 0 bits may be removed. | 11-06-2014 |