Abstract: Techniques are disclosed relating to data compression. In some embodiments, compression circuitry determines, at least partially in parallel for multiple different lossless compression techniques, amounts of data needed to represent, using a given lossless compression technique of the multiple lossless compression techniques, individual pixels in a set of pixels being compressed. The compression techniques may include neighbor, origin, and gradient techniques, for example. The compression circuitry may select one of the compression techniques based on comparison, among the compression techniques, of sums of: the determined amount of data for an individual pixel for a given lossless compression technique and compression metadata size for a given lossless compression technique. The compression circuitry may generate and store information that encodes values for the set of pixels using the selected compression technique.

Abstract: A train-linking lossless data compressor examines a block of data and uses a same coder to generate a same code when all data values in the input block are identical. When the input data is not all the same value, then a Gaussian coder, a Laplace coder, and a delta coder are activated in parallel. The three compressed code lengths are compared and the smallest code length is output as the compressed code when it is smaller than a copy code length. The copy code is a tag followed by copying all the data in the input block. When the smallest of the three compressed code lengths is larger than the copy code length, the file is not compressible, and the copy code is output. No frequency table is required so latency is low. The delta coder subtracts data values from an average value of the last data block.

Abstract: An embodiment of the invention may include a method, computer program product and system for saving data received from a host computing device to a storage system. The storage system includes at least one processor and at least one storage. An embodiment may include storing the received data to the storage on a record basis. A record includes a record header including information indicative of an implemented compression method of the record. An embodiment may include monitoring a processing load of the at least one processor. In response to the processing load being less than a predetermined level, an embodiment may include further compressing the record utilizing a high-ratio compression method based on the record requiring further compression. An embodiment may include updating the record header information to reflect details of the utilized a high-ratio compression method. An embodiment may include storing the further compressed record to the storage.

Abstract: A stopping criterion for a turbo-encoding method. The criterion is based on a state metrics calculated by a forward-backward recursion in a coding trellis of an elementary encoder. If, for at least one elementary decoding stage, forward state metrics of a last symbol of a block or backward state metrics of a first symbol of a block exceeds a first threshold, the turbo-decoding iterations are stopped. If it is not the case, it is further checked whether the state metrics exceeds a second threshold and if the absolute value of the difference between the current state metrics and the state metrics obtained at the previous iteration lies below a given margin. In the affirmative, the turbo-decoding iterations are stopped and a hard decision is taken on extrinsic values.

Abstract: A stopping criterion for a turbo-coding method. The criterion is based on states of a trellis determined by forward-backward recursion. If, for at least one elementary decoding stage, a transition ending state of a previous symbol is found identical to a transition starting state of a current symbol, for every symbol of the block but a first one and a last one, the decoding path is considered as consistent, a hard decision on the extrinsic information is made, and the turbo-decoding stops.

Abstract: Hybrid range coding/combinatorial coding (FPC) encoders and decoders are provided. Encoding and decoding can be dynamically switched between range coding and combinatorial according to the ratio of ones to the ratio of bits in a partial remaining sequence in order to reduce the computational complexity of encoding and decoding.

Abstract: A method for encoding an input file into an output file that is compressed so that the number of bits required to represent the output file is less than the number of bits of the input file. The encoding method includes the parsing of the input file into a series of data items, the data items having an order and collectively corresponding to the input file. The encoding method compares the series of data items against a static dictionary having at least mappings between terminal sequence pointers and representations of data items.

Abstract: A method for encoding an input file into an output file that is compressed so that the number of bits required to represent the output file is less than the number of bits of the input file. The encoding method includes the parsing of the input file into a series of data items, the data items having an order and collectively corresponding to the input file. The encoding method compares the series of data items against a static dictionary having at least mappings between terminal sequence pointers and representations of data items.

Abstract: A method of automatically generating and verifying programmable logic controller (PLC) code. The method includes the steps of constructing a neutral control model file, determining whether the neutral control model file is correct, generating PLC code if the neutral control model file is correct, verifying whether the PLC code is correct, and using the PLC code to build a tool.

Abstract: The present invention offers a method and a circuit for generating codes enabling transmission of long-codes to start on a reverse channel in a shorter waiting time. The method involves corresponding a shift quantity between the beginning of a sequence M or long-codes cycle, and each timing to a combination of a plurality of masking data; determining a combination of masking data for timing to start generation of long-codes in response to a transmission request at a point of time as soon as possible; and shifting of an initial value of a vector according to the masking data.

Abstract: A data compression method and apparatus therefor effects the steps of (a) obtaining an N-bit information word from a bit stream; (b) compressing the N-bit information word into an X-bit information word where X is less than N; (c) obtaining an (N-X)-bit information word from the bit stream; (d) producing a new N-bit information word using the compressed X-bit information word and the (N-X)-bit information word, and (e) repeatedly performing steps (b) through (d) if the new N-bit information word is compressible and otherwise repeatedly performing steps (a) through (d). A data expanding method and apparatus effects includes the steps of: (a) obtaining an (N-X)-bit information word from an N-bit information word, (b) expanding the remaining X-bit information word into an N-bit information word, excluding the (N-X)-bit information word, and (c) repeatedly performing steps (a) and (b) until an N-bit information word is restored.

Abstract: An input data sequence is divided into fixed-length source segments, and each source segment is predicted from preceding data. The data are coded as a sequence of coded segments, each designating a non-negative number of correctly predicted segments and a non-negative number of literal segments. The literal segments are inserted into the coded data among the coded segments. The coded data are decoded by decoding each coded segment, predicting the designated number of correctly predicted segments from previously decoded data, and copying the literal segments. The length of the coded segments may vary according to the number of consecutive correctly predicted segments. The prediction rule, or the original data, may be modified under certain conditions, in order to increase the predictability of the source segments.

Abstract: A data compression process and system that identifies the data type of an input data stream and then selects in response to the identified data type at least one data compression method from a set of data compression methods that provides an optimal compression ratio for that particular data type, thus maximizing the compression ratio for that input data stream. Moreover, the data compression process also provides means to alter the rate of compression during data compression for added flexibility and data compression efficiency. Furthermore, a system memory allocation process is also provided to allow system or user control over the amount of system memory to be allocated for the memory intensive data compression process. System memory allocation process estimates the memory requirement to compress the input data stream, and allocates only that amount of system memory as needed by the data compression for memory allocation efficiency.

Abstract: In order to employ an output register having a finite number of stages in an arithmetic encoder, it is necessary to provide carryover control, otherwise a register having an impractically large number of stages would be required, i.e., a so-called "infinite" register. The so-called "infinite" output register is emulated by employing a counter and a finite register. To this end, a count is accumulated of sets, i.e., bytes, of consecutive prescribed logical signals of a first kind, i.e., logical 1's, being generated by an arithmetic coding register and possibly modified by a carry indication. The accumulated count is then employed to supply as an output a like number of sets including logical signals of a second kind, i.e., logical 0's, or logical signals of the first kind, i.e., logical 1's, depending on whether or not a carry would propagate through the stages of the so-called "infinite" register being emulated.

Abstract: A method of and apparatus for converting between first and second digital data formats is disclosed whereby digital words of the first format are analyzed to detect an upper bandwidth limit of a corresponding analog signal in an interval thereof defined by such words and to determine the level of the analog signal at the beginning of such interval. A digital word of the second format is encoded with first and second pluralities of bits representing the determined upper bandwidth limit and the level of the corresponding analog signal at the beginning of the interval.

Abstract: A method and apparatus for generating signals representing a plurality (p) of n bit words corresponding to respective input signals. The apparatus comprises a basic word generator (7) for generating first signals representing m basic words (A-D) whereby the p words are the same as or are cyclic rearrangements of the n bits of the m basic words. Control means including combinatorial logic (33) determines the one of the p words corresponding to each input signal and generates corresponding control signals. Selection means including optical modulators (10-13, 20-25) are responsive to the control signals for selecting the appropriate first signal, if necessary after recycling by imposing selected delays, to constitute an output signal corresponding to the determined one of the p words.