Methods, systems, and computer programs for compressing nucleic acid sequence data. A method can include obtaining nucleic acid sequence data representing: (i) a read sequence, and (ii) a plurality of quality scores, determining whether the read sequence includes at least one “N” base, based on a determination that the read sequence includes at least one “N” base, generating, by one or more computers, a first encoding data set by using a first encoding process to encode each set of four quality scores of the read sequence into a single byte of memory, and using a second encoding process to encode the first encoded data set, thereby compressing the data to be compressed.

Data segments and metadata segments to be stored in a storage system, where the data segments are deduplicated segments and each of the metadata segments includes a fingerprint for the corresponding data segment, for each of the metadata segments. It is determined that the metadata segment contains one or markers inserted by a client device of the storage system. The metadata segment is examined to determine whether the metadata segment satisfies a predetermined condition. In response to determining that the metadata satisfies the predetermined condition, the metadata segment is compressed using a predetermined compression algorithm. The compressed metadata segment is stored in the storage system, otherwise the metadata segment is stored in the storage system without compression. Thereafter, the data segments are stored in the storage system.

Updating cumulative distribution functions (CDFs) during arithmetic encoding can be a challenge because the final element of the CDF should remain fixed during the update calculations. If the probabilities were floating-point numbers, this would not be too much of a challenge; nevertheless, the probabilities and hence the CDFs are represented as integers to take advantage of infinite-precision arithmetic. Some of these difficulties may be alleviated by introducing a “mixing” CDF along with the active CDF being updated; the mixing CDF provides nonlocal context for updating the CDF due to the introduction of a particular symbol in the encoding. Improved techniques of performing arithmetic encoding include updating the CDF using two, one-dimensional mixing CDF arrays: a symbol-dependent array and a symbol-dependent array. The symbol-dependent array is a sub array of a larger, fixed array such that the sub array selected depends on the symbol being used.

An apparatus comprises a processing device configured to collect system state information from host devices, to split the collected system state information into logical chunks, and to determine, based at least in part on a plurality of factors, a compression level to be applied to each of the logical chunks. The plurality of factors comprise a first factor characterizing a time at which the collected system state information is needed at a destination device and at least a second factor characterizing resources available for at least one of performing compression of the collected system state information and transmitting the collected system state information over at least one network to the destination device. The processing device is further configured to apply the determined compression level to each of the logical chunks to generate compressed logical chunks, and to transmit the compressed logical chunks to the destination device.

Video coding systems or apparatus utilizing context-based adaptive binary arithmetic coding (CABAC) during encoding and/or decoding, are configured according to the invention with an enhanced binarization of non-zero Delta-QP (dQP). During binarization the value of dQP and the sign are separately encoded using unary coding and then combined into a binary string which also contains the dQP non-zero flag. This invention capitalizes on the statistical symmetry of positive and negative values of dQP and results in saving bits and thus a higher coding efficiency.

A system comprises an encoder configured to compress attribute information and/or spatial for a point cloud and/or a decoder configured to decompress compressed attribute and/or spatial information for the point cloud. To compress the attribute and/or spatial information, the encoder is configured to convert a point cloud into an image based representation. Also, the decoder is configured to generate a decompressed point cloud based on an image based representation of a point cloud. A processing/filtering element utilizes occupancy map information and/or auxiliary patch information to determine relationships between patches in image frames and adjusts encoding/decoding and/or filtering or pre/post-processing parameters based on the determined relationships.

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.

The entropy coding of a current part of a predetermined entropy slice is based on, not only, the respective probability estimations of the predetermined entropy slice as adapted using the previously coded part of the predetermined entropy slice, but also probability estimations as used in the entropy coding of a spatially neighboring, in entropy slice order preceding entropy slice at a neighboring part thereof. Thereby, the probability estimations used in entropy coding are adapted to the actual symbol statistics more closely, thereby lowering the coding efficiency decrease normally caused by lower-delay concepts. Temporal interrelationships are exploited additionally or alternatively.

Video coding systems or apparatus utilizing context-based adaptive binary arithmetic coding (CABAC) during encoding and/or decoding, are configured according to the invention with an enhanced binarization of non-zero Delta-QP (dQP). During binarization the value of dQP and the sign are separately encoded using unary coding and then combined into a binary string which also contains the dQP non-zero flag. This invention capitalizes on the statistical symmetry of positive and negative values of dQP and results in saving bits and thus a higher coding efficiency.

A method for encoding digital images or video streams, includes a receiving phase, wherein a portion of an image is received; a graph weights prediction phase, wherein the elements of a weights matrix associated to the graph related to the blocks of the image (predicted blocks) are predicted on the basis of reconstructed, de-quantized and inverse-transformed pixel values of at least one previously coded block (predictor block) of the image, the weights matrix being a matrix comprising elements denoting the level of similarity between a pair of pixels composing said image, a graph transform computation phase, wherein the graph Fourier transform of the blocks of the image is performed, obtaining for the blocks a set of coefficients determined on the basis of the predicted weights; a coefficients quantization phase, wherein the coefficients are quantized an output phase wherein a bitstream comprising the transformed and quantized coefficients is transmitted and/or stored.