83 results about "Delta encoding" patented technology

The invention provides a block-encoded modulation scheme using multi-level partitioning techniques. This scheme is made transparent to phase ambiguities of ±pi/2 and of pi, by means of differential encoding and appropriate mapping, it is applicable to 16-QAM modulation, and it has theoretical encoding gain that is optimal for the rate of the code. The decoder associated with this scheme uses the Wagner algorithm which is much less complicated to implement than the Viterbi algorithm or than the Reed-Solomon algorithm.

The invention discloses an intra-frame lossless compression coding method based on an HEVC (high efficiency video coding) frame, wherein the method is low in time complexity and high in prediction accuracy and increases compression ratio. By the aid of the HEVC frame, a coding unit can be adaptively divided according to image flatness, the best division scheme is determined, and the optimal prediction mode is selected. DPCM (differential pulse code modulation) differential codes are used for preliminary prediction, prediction errors are possibly large when only the differential codes are used for an area with complex texture, and accordingly, prediction values are corrected for the area by means of error compensation. By combining the two methods, reduction of time complexity and improvement of prediction accuracy can be effectively compromised. Distribution characteristics of residual errors depend on the prediction mode, so that the scanning sequence of the residual errors is determined according to the prediction mode, and entropy coding can be more effective.

Methods and systems for compressing and decompressing 3-D geometry data which includes regularly tiled surface portions. One compression method includes representing a surface portion as a "vertex raster", which comprises specifying an extent value and encoding the vertex parameter values of vertices within the surface portion. The extent of the surface portion specifies the arrangement of vertices within the surface portion, and allows the vertices to be properly assembled into drawing primitives during decompression. The encoded vertex parameter values may be encoded globally (by setting initial values and corresponding delta values), locally (on a per-vertex basis), or using a combination of these techniques. Absolute, delta encoding, or delta-delta encoding may be utilized for these parameter values. Vertex parameters which may be encoded in this manner include position, color, normals, z-displacement values, texture map coordinates, and surface material properties. Additionally, connectivity information may also be encoded using this compression method by specifying quad split bits and half-resolution edges. Quad split bits are used to tessellate a quadrilateral formed by neighboring vertices of a surface portion according to the direction of the strongest color change. Half-resolution edges are utilized to gradually shift from an area of high resolution to an adjacent surface portion represented in lower resolution. For graphical objects which include a plurality of adjacent surface portions, a step command is disclosed which allows data from one surface portion to be advantageously reused. Decompression of a vertex raster representation may comprise decoding the extent value, global parameter values, and a per-vertex stream of local parameter values.

The invention discloses a digital image compressing, encrypting and encoding combined method, and belongs to the technical field of image encrypting. The method is achieved on the basis of the JPEG compressing and encoding standard which is most widely applied at present, and the encrypting algorithm based on chaos is integrated with the encoding process; according to the characteristic that DC coefficients and AC coefficients are separately encoded on the basis of the JPEG standard, the DC coefficients and the AC coefficients of an image are separately encrypted; in order to give consideration to both security and compressing efficiency, all the DC coefficients and part of the AC coefficients are encrypted through the method, coefficients at the same positions in all DCT blocks are divided into different groups and are scrambled and diffused within the groups, and damage to differential encoding and run length encoding in the encrypting process is reduced as much as possible; scrambling and diffusing are achieved on the basis of logistic chaotic mapping and Chebyshev chaotic mapping respectively. The experiments prove that the method has high data compressing capacity while providing effective image data security protection.

Methods and systems for compressing and decompressing 3-D geometry data which includes regularly tiled surface portions. One compression method includes representing a surface portion as a "vertex raster" by specifying an extent value and encoding the vertex parameter values of vertices within the surface portion. The extent value specifies the arrangement of vertices within the surface portion and allows the vertices to be properly assembled into drawing primitives during decompression. The encoded vertex parameter values (such as position, color, normals, z-displacement values, texture map coordinates, and surface material properties) may be encoded globally (by setting initial values and corresponding delta values), locally (on a per-vertex basis), or using a combination of these techniques. Absolute, delta, or delta-delta encoding may be utilized for these parameter values. Connectivity information may also be encoded using this compression method by specifying quad split bits and half-resolution edges. For graphical objects which include a plurality of adjacent surface portions, a step command may be used to allow reuse of data for more than one surface.

An encoding apparatus operable to encode video data representing successive images, each image including a plurality of pixels. The apparatus includes a differential encoder arranged to encode each image as one or more predetermined image regions. Each image is being encoded as a reference value and at least one differential pixel value. The differential pixel value(s) are derived in dependence on the reference value and/or other differential pixel value(s) in accordance with an order of encoding dependency; in which, for each image region, the differential encoder is operable in a first encoding mode for a first subset of the images to encode the image region using a first order of encoding dependency and in a second encoding mode for a second, different, subset of the images to encode the image region using a second, different, order of encoding dependency. The first and second subsets of images are arranged with respect to one another so that, from image to image, each image region is encoded in accordance with a predetermined sequence of orders of encoding dependency.

A method and apparatus provide simultaneous bi-directional communications through a barrier using a pair of piezoelectric transducers. Outside-to-inside transmission of differentially encoded binary data is only sampled at the inside when a known repeated bit in a Barker sequence is transmitted in the other direction. Differentially encoded data is translated based on the absolute value of differences between each signal envelope sample and the previous signal envelope sample. Inside-to-outside data is transmitted by varying an electrical load on the inside transducer to vary the proportion of a continuous wave signal it reflects. The reflected portion of the continuous wave changes the electrical impedance of the outside transducer and this change is measured and interpreted as binary data. Two frequency selection algorithms select minimally sufficient and then optimal frequencies for power and data transmission by a frequency stepping process.

The invention provides an MPEG2 (Moving Picture Experts Group 2) video watermarking realization method based on a DC (Discrete Cosine) coefficient, belonging to the field of computer information security. According to the method, watermarking information is embedded into a luminance component of an I frame of an encoded video so as to ensure the robustness of a video watermarking; the last difference DC coefficient of a Y component of the last macro block of each strip which has the smallest influence on the video quality is selected at the embedding position of the watermarking, so that video data of other strips is not influenced after the DC coefficient is changed; in an embedding and extracting algorithm of the watermarking, watermarking information is embedded on the basis that encoding quantity of a DCT (Discrete Cosine Transformation) coefficient is not changed before and after the watermarking is added by combining the DC coefficient in an MPEG2 video and utilizing a Huffman difference encoding characteristic; the embedding and the extraction of the watermarking do not relate to lots of data DCT and IDCT (Inverse Discrete Cosine Transformation) conversion, quantization and inverse quantization, the complexity of a video watermarking system is reduced greatly, the embedding and extracting efficiency of the watermarking is improved and the accuracy of watermarking information extraction is enhanced.

The invention discloses an encoder which comprises an encoding and modulating module, an interweaving module, a serial-parallel transformation module and a differential encoding module. After an input information sequence line is modulated and encoded by the encoding and modulating module, weighting and differential encoding processing is respectively carried out for multipath parallel signals through the differential encoding module, and an encoding signal is obtained and output. The invention also discloses a decoder and a decoding method. In the technical scheme disclosed by the invention, through adopting a simpler and highly efficient data processing method, the complexity of decoding and demodulation algorithms of a differential encoding technology and a differential modulation technology is reduced, the processing delay is reduced, and the speed of data processing is improved.

The present invention provides an optical communication method, comprising: performing modulation on the obtained bit stream data to generate modulated signals; performing differential encoding on the modulated signals to generate differentially encoded signals; converting the differentially encoded signals into electrical signals; and mapping the electrical signals onto optical carriers to generate optical signals for transmission. With the present invention, it is possible to enhance the system's capability of resisting inter-carrier interference without decreasing spectrum efficiency, hence improving the tolerance of existing optical communication systems towards laser linewidth, fast-changing PMD, optical fiber nonlinearity, inter-channel interference and other damages, greatly enhancing system performances.

An encoder capable of reducing the degradation of the quality of the decoded signal in the case of band expansion in which the high band of the spectrum of an input signal is estimated from the low band. In this encoder, a first layer encoding section (202) encodes an input signal and generates first encoded information, a first layer decoding section (203) decodes the first encoded information and generates a first decoded signal, a characteristic judging section (206) analyzes the intensity of the harmonic structure of the input signal and generates harmonic characteristic information representing the analysis result, and a second layer encoding section (207) changes, on the basis of the harmonic characteristic information, the numbers of bits allocated to parameters included in second encoded information created by encoding the difference between the input signal and the first decoded signal before creating the second information .

3D models often have a large number of small to medium sized connected components, with small numbers of large triangles, often with arbitrary connectivity. The efficiency of compact representation of large multi-component 3D models can be improved by detecting and representing similarities between components thereof, even if the components are not exactly equal. The invention uses displacement maps for encoding two or more different but similar geometry patterns differentially, based on clustering and a cluster representative surface. A method for encoding a plurality of geometry patterns comprises detecting and encoding identical copies of geometrical patterns, detecting and clustering similar geometry patterns, and detecting partial similarity. The detecting partial similarity comprises generating a cluster representative surface, generating for at least one clustered geometry pattern a displacement map, and encoding the common surface and the displacement maps.

The invention relates to a wave recording data processing method and a system. The method comprises a data zipping step which includes the following aspects in details: calculating data difference; extracting from the data difference value the sign bits and combining them into symbol characters for storage; dividing the absolute value of the data difference value into fragments in an equal length; gathering how many times the fragments appear and taking their appearing times as weights to generate a fragment Huffman coding tree; gathering how many times measuring ranges appear and taking their appearing times as weights for to generate a measuring range Huffman coding tree; and according to the Huffman coding trees, coding and storing the data difference fragments and the measuring ranges; In the invention, a wave shape data zipping file storing structure comprises a recording head and a recording medium. The recording head comprises recording basic information, coding tree information and coding zone information. The recording medium comprises a coding tree zone, a symbol coding zone, a measuring range coding zone and a data difference coding zone. The system consists of a CPU processor, a sampling system, an external storing device and a wave recording triggering system. The sampling system, the external storing device and the wave recording triggering system are all connected to the CPU processor respectively. According to the invention, the compression ratio is influenced by waveform distortion to a small extent. The method and system are suitable for mixed zipping of state quantity and analog quantity. As they consume less processing memory and time, so they are cost-effective in implementation.

A typical English pronunciation dictionary takes up to 1,826,302 bytes in ASCII to store. A five times compression while maintaining computability is achieved by prefix delta encoding of the word and error encoding of the pronunciation.

The present invention provides a JPEG image encryption method compatible in format and invariant in size, and belongs to the technical field of multimedia information safety. The method of the presentinvention includes three encryption steps: 1) classifying and scrambling AC coefficient-encoded zero runs; 2) grouping and scrambling DC coefficient-differentially encoded adjacent same symbols; 3) grouping and iteratively encrypting DC coefficient differential codes. According to the invention, the method can be used for protecting the safety and the privacy of military images, commercial images, medical images or personal images when the images are transmitted through a public channel or stored in the public cloud. The method aims to improve the ubiquitous defect that the size of a ciphertext image increases and the format compatibility of the image is not ideal based on existing JPEG image encryption methods. The above method can resist the known-plaintext attack, and substantially maintain the size of the ciphertext image to be unchanged. Meanwhile, the format compatibility is better and the encryption strength is adjustable.

A memory structure of a computer system receives an address tag associated with a computational value, generates a modified address which corresponds to the address tag using a compression function, and stores the modified address as being associated with the computational value. The address tag can be a physical address tag or a virtual address tag. The computational value (i.e., operand data or program instructions) may be stored in the memory structure as well, such as in a cache associated with a processing unit of the computer system. For such an implementation, the compressed address of a particular cache operation is compared to existing cache entries to determine which a cache miss or hit has occurred. In another exemplary embodiment, the memory structure is a memory disambiguation buffer associated with at least one processing unit of the computer system, and the compressed address is used to resolve load/store collisions. Compression may be accomplished using various encoding schemes, including complex schemes such as Huffinan encoding, or more elementary schemes such as differential encoding. The compression of the address tags in the memory structures allows for a smaller tag array in the memory structure, reducing the overall size of the device, and further reducing power consumption.

The invention relates to demodulation method and device of differential 8-ary phase shift key (D8PSK) modulation signals of a VHF (very high frequency) digital link (VDL) communication system. Aiming at the defects of the prior art, by combining with high-speed operation property of the current low-cost FGPA (field programmable gate array) element, the invention discloses demodulation method and device of D8PSK modulation signals of a VDL communication system. Under the premise of meeting the VDL physical layer link specification, the invention can greatly improve real-time of digital signal processing and lower the computation complexity as well as ensure the performance of a baseband demodulation system. By improving the sampling rate of baseband signals, fully utilizing interaction information contents of adjacent symbols brought by differential encoding and using the frequency difference estimation value of the last symbol as a frequency difference estimation value of the next symbol during the differential demodulation, and under the premise of meeting the VDL physical layer link specification, the invention can greatly improve the real-time of digital signal processing and lower the computation complexity.

The invention relates to a complexity image lossless compression method supporting random access and belongs to the technical field of video image compression. The method includes the following steps that an image is segmented into macro blocks which are divided into three regions; intra-frame detection is carried out; a mode with the minimal code bit cost is chosen to obtain a residual image of the optimal predicting mode; the residual image is segmented into different small blocks to undergo self-adaption variable-length encoding and lossless compression code streams are obtained through a compression code stream generating module. The problem of data dependency of boundary pixels among the macro blocks is solved by dividing the macro blocks into the three regions. A high data compression rate can be achieved by means of a block/pixel self-adaption predication, differential encoding and self-adaption variable-length encoding combination compression method. The lossless compression effect for the 1080p resolution ratio can be more than 50%.

A genomic data decoder may jointly compress and encrypt genomic data alignment information while preserving the privacy of sensitive genomic data elements at retrieval stage. Genomic data alignment information organized as a read-based alignment data stream may be transposed into a position-based alignment data stream. The position-based alignment information may been coded into a reference-based alignment data stream. The reference-based alignment data stream may be encrypted with a combination of order-preserving encryption of the genomic position information and symmetric encryption of the reference-based alignment differential data. Differential encoding and entropy coding schemes may further compress the reference-based alignment data stream. The resulting compressed and encrypted stream may be indexed and stored in a biobank storage unit. A genomic data decoder may efficiently retrieve, decrypt and decode a specific subset of the resulting compressed and encrypted stream without leaking information on the other genomic data subsets in the resulting stream.

This invention provides a SAR complex image data real-time compressing method, comprising the following steps: first, dividing complex image into several blocks, compressing and encoding each unit of sub-block, two-dimension Fourier transforming the every sub-block, using sciagraphy to analyze transformed data to defining non-zero coefficient and its zone, quantizing non-zero coefficient; second, differential encoding position information in non-zero zone and setting it in the head of code stream, separately grid coding quantizing real part and imaginary part then through arithmetic encoding to form terminal code stream. The invention is characterized in meeting request of real-time and automatically compressing complex image data in space-borne system and high fidelity of phase.

The invention relates to a CT (Computed Tomography) data compression mechanism. The data compression method comprises the following steps: acquiring original image data; caching the data acquired by a detector; differential encoding, namely, performing differential encoding for the cached data; area dividing, namely, dividing a data array into N small arrays with the same size; comparing and selecting, namely, comparing and screening separated data blocks with previous data blocks; data compression, namely, performing secondary compression for the part with large data difference. According to the CT data compression method, a nondestructive compression method for original industrial CT projection data is provided for mass industrial CT data acquiring and transmission; the data can be compressed in a CT device employing a high-resolution and large-area flat panel detector; therefore, the transmission efficiency and data compression ratio can be effectively raised.