92 results about "Arithmetic encoder" patented technology

An entropy encoding/decoding scheme uses an arithmetic encoder/decoder together with a context modeler for performing a context-based adaptive binary arithmetic coding, which is especially suited for video compression applications. The context modeler includes an initializer for initializing the context modeler by determining and providing initialization probability information to the arithmetic encoder, the initialization probability information to be used by the arithmetic encoder for processing a start symbol of a symbol sequence. The initializer is operative to determine the initialization probability information based on an estimation of the symbol statistics relating to the start symbol such that an initialization probability distribution is different from an equi-probable distribution for all symbols of the symbol set. By means of the initialization, the context-based adaptive binary arithmetic coding/decoding scheme is optimally adjusted before processing a start symbol of the symbol sequence so that no bit rate compression losses because of a delayed context-based adaptation are introduced.

A communication system (100) includes devices (102, 104, 200) for transmitting and receiving digital audio. The devices use audio encoders (210, 804) and decoders (222, 916) such as ACELP or DCT/IDCT to compress and decompress audio and use arithmetic encoders (212) and decoders (220) to encode and decode the compressed audio on-the-fly (without a codebook of pre-stored codes).

An image coding apparatus includes an image feature extraction means for generating character data which includes character codes corresponding to character images included in a document image and auxiliary information indicating the sizes and positions of the respective character images in the document image based on image data indicating the document image. The image coding apparatus generates a predictive document image for the document image based on the character data, and subjects the document image data to arithmetic coding in which the probability model is changed with reference to predictive document image data. In the image coding apparatus, the probabilities of white pixels and black pixels indicated by the probability model are very close to those in the character image, whereby the coding efficiency for the character image data in the arithmetic encoder is improved.

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.

Disclosed is a system and method for joint source-channel encoding, symbol decoding and error correction, preferably utilizing an arithmetic encoder with operational error detection space; and a combination sequential, and arithmetic, encoded symbol decoder structure.

A process may be utilized for encoding MBs. The process records a plurality of CABAC weight values for a first MB. The first MB resides in a first edge of a first frame in a plurality of images. Further, the process encodes the first MB with the plurality of CABAC weight values. In addition, the process initializes a second frame in the plurality of the images with the plurality of CABAC weight values. Finally, the process encodes a second MB with the plurality of CABAC weight values. The second MB resides in a second edge of a second frame in the plurality of images.

An encoder/decoder architecture including an arithmetic encoder that encodes the MSB portions of a Factorial Pulse Coder output, and that encodes an output of a first-level source encoder, e.g., MDCT. Sub-parts (e.g., frequency bands) of portions (e.g., frames) of the signal are sorted in increasing order based on a measure related to signal energy (e.g., signal energy itself). In a system that overlays Arithmetic Encoding on Factorial Pulse coding, the result is bits re-allocated to bands with higher signal energy content, yielding higher signal quality and higher bit utilization efficiency.

A method for realizing arithmetic-coding /decoding (ACD) includes mapping region carrying out ACD on original number domain onto logarithm domain to realize said ACD directly through addition and subtraction when binary coding/decoding course is carried out in arithmetic coder/decoder, using approximate calculation to realize data conversion between two said domains in logarithm domain ACD course, making update as per probability as required after one symbol being coded/decoded and realizing said update by addition and subtraction in logarithm domain.

The invention provides an encoding interval update and normalization module, an encoding lower limit update and normalization module, a code stream extraction module, a binary arithmetic encoder and an encoding method thereof. The binary arithmetic encoder comprises an encoding interval update and normalization module, an encoding lower limit update and normalization module and a code stream extraction module, wherein the encoding interval update and normalization module, the encoding lower limit update and normalization module and the code stream extraction module form a parallel three-level stream line structure, and the code stream extraction module can process one or more encoding symbols within one clock cycle. Complete parallel is realized, and the problem of poor parallel in the prior art is solved; in addition, the common use of different encoding modes is realized by a selector to improve the circuit reusability and reduce the hardware cost; and moreover, the code stream extraction operation of the code stream extraction method is simple, and no additional FIFO resource is needed.

The invention discloses a binary arithmetic encoder for inputting and outputting parallel-decoded singlebytes or multibytes. In an algorithm, MPS and LPS of each input symbol are provided with a logarithmic probability index respectively in accordance with the probabilities of the input symbol, and the logarithmic probability indexes are utilized to express interval sizes in the logarithmic encoding. In the algorithm, table look-up is utilized to realize mapping for the logarithmic probability indexes and the interval sizes, and shift operation is utilized to reduce the size of a static table. The algorithm can realize interval subdivision by adding the logarithmic probability indexes.

The invention discloses a method for effectively encoding and decoding a JPEG2000 image based on a vision potential attention target area. The method comprises the following steps of: before the image is encoded, dividing the image into a plurality of Tile blocks based on the potential target area of different attentions and pre-assigning corresponding target code rates according to vision potential attention target area extraction technology; and then carrying out code stream organization and packaging to realize image compression through quantization, adaptive wavelet transformation, and a bit plane encoding and arithmetic encoder code word reset mechanism on the basis of potential attention target area quality layer code rate control. When network band width is insufficient, the image reconstruction quality of a more-concerned target area can be exchanged at the expense of part of code rates of the target area with smaller potential attention; simultaneously, retractable high-efficiency image encoding and decoding technology is combined with a qualified content based on the potential attention target area.

A method stores, in a first memory location in a context weight update engine in an arithmetic encoder, a context weight value. The method also stores, in a second memory location in the context weight update engine in the arithmetic encoder, a context weight adjustment value. Further, the method reads, in a first clock cycle, the context weight value and a first binarization value from the first memory location. In addition, the method writes, in a second clock cycle, the context weight adjustment value and a second binarization value into the first memory location. The second binarization value is distinct from the first binarization value.

An adaptive entropy coder is coupled with a localized conditioning context to provide efficient compression of images with localized high frequency variations. In one implementation, an arithmetic coder can be used as the adaptive entropy coder. The localized conditioning context includes a basic context region with multiple context pixels that are adjacent the current pixel, each of the context pixels having an image tone. A state is determined for the basic context region based upon a pattern of unique image tones among the context pixels therein. An extended context region that includes the basic context region is used to identify a non-local trend within the context pixels and a corresponding state. A current pixel may be arithmetically encoded according to a previously encoded pixel having the same tone or as a not-in-context element. In one implementation, a not-in-context element may be represented by a tone in a color cache that is arranged as an ordered list of most recent not-in-context values.

An encoder is configured to compress point cloud geometry information using an octree geometric compression technique that utilizes a binary arithmetic encoder, a look-ahead table, a cache, and a context selection process, wherein encoding contexts are selected based, at least in part, on neighborhood configurations. In a similar manner, a decoder is configured to decode compressed point cloud geometry information utilizing a binary arithmetic encoder, a look-ahead table, a cache, and a context selection process.

The invention discloses a JPEG2000 EBCOT (Embedded Block Coding with Optimized Truncation) encoder based on an Avalon bus, relating to the JPEG2000 EBCOT encoder, and solving the problems of low speed, poor flexibility and complex process of the JPEG2000 EBCOT encoder in the prior art. The EBCOT encoder comprises an Avalon bus interface and an EBCOTTier-1 encoder, wherein the input ends of a clock signal, a reset signal, a start signal, an encode-finishing signal, an encode block write signal, an encode block data signal, an encode block address signal, an output byte memory address signal and an output byte memory data signal of the Avalon bus interface are connected with an encode control module which is connected with msb bitplane encoders, wherein msb is a numerical value of a highest bitplane detection module detecting the highest bitplane of the encode control module; the bitplane encoders are connected with an arithmetic encoder; and the arithmetic encoder is connected with an output byte memory RAM (Random Access Memory). The encoder can be better applied to the whole JPEG2000 encoders.

The invention discloses a method for designing structure and key circuit of synchronous pipelining arithmetic coder suitable to hardware of image compression and video processing. For instance, JPEG2000 chip is capable of coding N pieces of input within N+3 timing cycle based on context-sensitive self-adapting arithmetic coder. Thus, following change is taken: flow of arithmetic coder in JPEG2000 protocol is converted to pipeline structure in three steps and assistant steps; putting forward optimizing algorithm in second and third steps in pipeline, index selection logic of Qe table under continuous CX input etc. Optimized result meets requirement of 200M timing clock under .25 micro techniques.

This invention is a JPEG2000 arithmetic encoder with improvements to conventional JPEG2000 encoder implementations. This invention decouples co-efficient bit modeling from arithmetic encoding, eliminates the RENORME while loop through least most bit detection, decouples encoding from BYTEOUT, exploits parallelism across conditional execution paths, uses look-up table storage and packing of context state data and eliminates memory dependencies through direct register forwarding.

An image compressing apparatus carrying out code amount control upon JPEG2000 coding, in which the number of coding passes and a code amount for each code block generated by a MQ (arithmetic) coder are input, and the number of coding passes and the code amount are determined based on a first code amount control standard and a second code amount control standard given for each code block. For a specific code block, the second code amount control standard is used to determine the number of coding passes and the code amount, while, for the other code blocks, the first code amount control standard is used to determine the number of coding passes and the code amount.

The invention provides a discontinuous context modeling and maximum entropy principle based gene compression method. The method includes that in a first stage, two actual situations with reference sequences and without reference sequences are considered simultaneously, and repetitive sequences in or among gene sequences are represented with a dictionary method, so that compression efficiency is improved; in a second stage, a statistical encoder is composed of a predictor and an arithmetic encoder, the predictor introduces a modeling scheme in a discontinuous bit context combination type on the basis of traditional continuous context models for non-repetitive sequences, and prediction probabilities independently generated by all models are merged with a Logistic regression formula generated on the basis of the maximum entropy principle, so that a more accurate final prediction probability value is obtained and put into the arithmetic encoder. By the method, compression efficiency can be improved remarkably, and efficient storage is realized.