4714 results about "Data compression" patented technology

A system and method of optimizing transmission of a program to multiple users over a distribution system, with particular application to video-on-demand for a CATV network. The system includes, at a head end of the CATV network a scheduling and routing computer for dividing the video program stored in long term fast storage or short term fast storage into a plurality of program segments, and a subscriber distribution node for transmitting the program segments in a redundant sequence in accordance with a scheduling algorithm. At a receiver of the CATV network there is provided a buffer memory for storing the transmitted video program segments for subsequent playback whereby, in use, the scheduling algorithm can ensure that a user's receiver will receive all of the program segments in a manner that will enable continuous playback in real time of the program. Under the control of controller the receiver distinguishes received program segments by a segment identifier so that redundant segments captured in capture memory are then stored in buffer memory from which the segments can be retrieved and decompressed in data compressor for immediate or subsequent viewing. In one embodiment, the method of this invention includes dividing at least some segments into fragments, and transmitting one fragment of each segment during a playback interval of a duration, for example, equal to a playback time of a segment.

A data compression system and method for that is capable of detecting and eliminating repeated phrases of variable length within a window of virtually unlimited size.

A method is disclosed for compressing a frame of data representing parameter values, a time at which each parameter value was recorded, and an orientation of a sensor at the time each parameter value was recorded. Generally the method includes performing a two-dimensional transform on the data in the orientation domain and in a domain related to the recording time. In one embodiment, the method includes calculating a logarithm of each parameter value. In one embodiment, the 2-D transform includes generating a Fourier transform of the logarithm of the parameter values in the azimuthal domain, generating a discrete cosine transform of the transform coefficients in the time domain. This embodiment includes quantizing the coefficients of the Fourier transform and the discrete cosine transform. One embodiment of the method is adapted to transmit resistivity measurements made by an LWD instrument in pressure modulation telemetry so that while-drilling images of a wellbore can be generated. The one embodiment includes encoding the quantized coefficients, error encoding the encoded coefficients, and applying the error encoded coefficients to the pressure modulation telemetry.

A service gateway provides a proxy between a client protocol and a plurality of standard communication protocols. The service gateway provides asymmetrical routing, data compression and encryption to optimize client processing power and communication link bandwidth. The service gateway enables content translation between clients and service providers. The service gateway keeps track of client available memory and sequence numbers in messages to generate error codes when applicable. A store and forward message capability is provided along with abstract session identifiers. The service gateway supports user datagram protocol.

A method and apparatus for increasing the bandwidth of a memory controller system are provided. According to the invention, data received at an interface of a memory controller system is compressed in the memory controller by a compression engine for storage in associated memory. The address of the data written to memory is maintained in a memory controller. When data is read from the memory for provision to an interface of the memory controller, the memory manager retrieves the data from memory and provides it to a decompression engine. The decompression engine restores the data to its original, uncompressed form. The data is then provided to the appropriate interface.

A method for compressing a stream of application layer network traffic communicated over a transport layer connection of a virtual private network connection between a client and a server using an appliance. The appliance intercepts one or more transport layer packets of a stream of application network traffic communicated via a transport layer connection of a virtual private network connection between a client and a server. The appliance accumulates data from a payload of the intercepted transport layer packets, determines data accumulated for transmission should be compressed based on one or more compression trigger, and compresses the accumulated data into a self-contained compression block for transmission.

Methods and apparatus for dynamically adapting the degree of compression used in compressing data based upon the type of contents contained within a packet are disclosed. According to one aspect of the present invention, an apparatus that forwards data across a digital communications network includes a compression switch, a compression system, and an output interface. The compression switch receives the data, determines a content type associated with the data by examining the data, and assigns a compression level to the data in response to the determined content type. The compression system is arranged to compress the data based upon the compression level, while the output interface forwards the compressed data across the network. In one embodiment, the apparatus also includes a network congestion estimator that determines a level of network congestion.

A multi-function robotic device may have utility in various applications. In accordance with one aspect, a multi-function robotic device may be selectively configurable to perform a desired function in accordance with the capabilities of a selectively removable functional cartridge operably coupled with a robot body. Localization and mapping techniques may employ partial maps associated with portions of an operating environment, data compression, or both.

Adaptive control of codebook regeneration in data compression mechanisms. In one implementation, the present invention provides a means controlling the frequency of codebook updates based on expected performance gains resulting from codebook regeneration. The present invention, in one implementation, employs a mechanism that simulates the expected compression performance of a hypothetically, updated codebook. A compression module compares the simulated compression performance to the actual performance of the codebook used to compress the data, and updates the codebook if a threshold condition is satisfied.

An apparatus and method for image data compression performs a modified zero-tree coding on a range of image bit plane values from the largest to a defined smaller value, and a vector quantizer codes the remaining values and lossless coding is performed on the results of the two coding steps. The defined smaller value can be adjusted iteratively to meet a preselected compressed image size criterion or to meet a predefined level of image quality, as determined by any suitable metric. If the image to be compressed is in RGB color space, the apparatus converts the RGB image to a less redundant color space before commencing further processing.

A portable audio/visual program player comprising a video display, electrical-audio transducer, a central processing unit and associated logic and memory circuits. The portable audio/visual player is able to play pre-recorded programs from a memory device, which includes compress digital audio and video program information and a decoder program. The digital compression method comprises a series of compression methods to greatly reduce the amount of digital data. The data compression method is particularly suitable for motion video comprising cartoons and similar images, but is also suitable for other applications.

In optical filter systems and optical transmission systems, an optical filter compresses data into and/or derives data from a light signal. The filter way weight an incident light signal by wavelength over a predetermined wavelength range according to a predetermined function so that the filter performs the dot product of the light signal and the function.

In a memory system with a file storage system, an optimal file handling scheme is adaptively selected from a group thereof based on the attributes of the file being handled. The file attributes may be obtained from a host or derived from a history of the file had with the memory system. In one embodiment, a scheme for allocating memory locations for a write operation is dependent on an estimated size of the file to be written. In another embodiment, a scheme for allocating memory locations for a relocation operation, such as for garbage collection or data compaction, is dependent on an estimated access frequency of the file in question. In this way, the optimal handling scheme can be used for the particular file at any time.

A method and mechanism is disclosed for implementing storage and retrieval of data in a computing system. Data compression is performed on stored data by reducing or eliminating duplicate values in a database block. Duplicated values are eliminated within the set of data that is to be stored within a particular data storage unit. Rather than writing the duplicated data values to the data storage unit, the on-disk data is configured to reference a symbol table a single copy of each duplicated data value. Column reordering may be performed in an embodiment to further improve compression efficiency. The column reordering may be performed to allow efficient removal of trailing NULL values from on-disk storage.