195 results about "Hadamard transform" patented technology

A symbol sequence contained in a received signal comprising a cyclic convolution of a Walsh code multiplexed signal and a channel impulse response of a multipath channel is detected using Walsh Hadamard domain equalization techniques. The method comprises converting the received signal and the channel impulse response of the multipath channel from the time domain to the WHT domain, and determining the symbol sequence based on equalizing the received signal in the WHT domain using WHT spectra of the channel impulse response to remove inter-symbol interference from the received signal due to cross-correlation between Walsh codes.

A staring imaging system inputs a 2D spatial image containing multi-frequency spectral information. This image is encoded in one dimension of the image with a cyclic Hadamarid S-matrix. The resulting image is detecting with a spatial 2D detector; and a computer applies a Hadamard transform to recover the encoded image.

A method of data compression and transmission include splitting a wave function representative of an input data set into an arbitrarily oriented elliptical polarization state and a comparator wave function state, the comparator wave function state being transmitted to a detector. A quantum Fourier transform is performed on the arbitrarily oriented elliptical polarization state to yield a quantum computational product. A quantum Hadamard transform is performed on the quantum computational product to yield one of two possible quantum particle outputs. The input data set is reconstructed based upon the coincident arrival of the comparator wave function state and one of the two quantum particle outputs. A method is performed on either a quantum computer or a digital computer. An optical bench with appropriate electronics is particularly well suited to function as a quantum computer for the compression and transmission of data corresponding to sound.

An improvement to a predictive video encoding method or apparatus that includes selecting a mode class within which to choose an encoding algorithm to encode individual blocks of video information. Rather than implementing each algorithm in each mode class to ascertain an acceptable compression, the improvement eliminates searching through a class of encoding modes based simply on heuristics. The method comprises obtaining statistical information related to previous blocks of encoded video information, determining a mode class within which to chose a particular encoding algorithm based on the statistical information (e.g., heuristics) gathered, choosing an algorithm within the selected mode class using conventional techniques, and encoding the video information according to the chosen algorithm. Statistical information may include quantization parameters, prior encoding decisions, intensity or frequency values, or Hadamard transform coefficients of previously encoded macroblocks. Encoding complexity in the coder is reduced since one class of encoding modes is eliminated.

A symbol sequence contained in a received signal comprising a cyclic convolution of a Walsh code multiplexed signal and a channel impulse response of a multipath channel is detected using Walsh Hadamard domain equalization techniques. The method comprises converting the received signal and the channel impulse response of the multipath channel from the time domain to the WHT domain, and determining the symbol sequence based on equalizing the received signal in the WHT domain using WHT spectra of the channel impulse response to remove inter-symbol interference from the received signal due to cross-correlation between Walsh codes.

A mass spectrometer and associated methods analyze an ion beam by accumulating ions for a sequence of time periods, and driving the accumulated ions in pulses. Differing quantities of ions can be accumulated in the sequential pulses according to a pseudo-random sequence, and the slower ions are overtaken by the faster ions of a subsequent pulse. A mass spectrum may be reconstructed from an overlapping ion detector signal using an inverse of a weighted simplex matrix or inverse Hadamard transform techniques.

The invention discloses a non-local image denoising method based on low rank restoration. The method comprises the steps of (1) collecting an image, (2) carrying out gray transformation on the collected image, (3) establishing a three-dimensional similarity matrix through the global search of a similar pixel block for the image which is subjected to gray transformation, then carrying out hard threshold filtering on the discrete cosine transform and Hadamard transform coefficients of the three-dimensional matrix is carried out, obtaining the initial estimation of the similar pixel block with the removal of partial noise, and improving the matching accuracy of the similar pixel block with low rank restoration denoising while removing a large part of noise, and (4) with transform domain filtering as prior knowledge, searching a similar pixel block in a search area for an initially denoised reference pixel block, then forming the similarity matrix by using a similarity block corresponding to an original image, carrying out low rank matrix decomposition on the similarity matrix, effectively separating noise and a signal, and obtaining a final denoised image. The method has the advantages of a simple and fast algorithm, a high signal-to-noise ratio and good consistency and is especially suitable for the requirements of high quality noise reduction of large-scale images.

The Hadamard transform is used to spread data within data blocks in a multicarrier MIMO system, before transmission. In this manner, the negative effects caused by the clustering of bad subcarriers (i.e., subcarriers having a low transmission coefficient due to fading) may be reduced. In at least one embodiment, a MAP-type detection scheme is used in the receiver to extract bit reliabilities from the received signals.

A method of decoding encoded information communicated over a radio channel includes receiving a vector of encoded information transmitted by a wireless terminal. The encoded information includes an encoded representation of unencoded information bits that have been encoded using a first order Reed-Muller code. The method also includes generating a vector of transform values by performing a Hadamard Transform on the received vector and identifying a subset of the transform values based on scheduling information associated with the wireless terminal. Additionally, the method includes selecting, from the subset of transform values, one of the transform values based on a magnitude of the selected transform value and determining an estimate of the unencoded information bits based on a bit sequence associated with the selected transform value. In accordance with another embodiment of the present disclosure, an apparatus is operable to implement this method.

Backscatter imaging using Hadamard transform masking includes an area x-ray source with alternating, masked, Hadamard transform patterns. The total backscatter signal from a target for each pair of corresponding masks is recorded. The difference in signal strengths for each pair of corresponding masks is a direct measurement of the Hadamard transform coefficient for that mask. An image of the target is formed by performing an inverse discrete Hadamard transform on the complete matrix of coefficients.

In one embodiment, a Walsh-Hadamard decoder can have a hardware efficient Fast Hadamard Transform (“FHT”) engine. In one embodiment, the FHT engine can include an input to receive an input sequence to be decoded into a Walsh-Hadamard codeword. The FHT engine can further include a controller to correlate the received input sequence with a plurality of Walsh-Hadamard codewords using two add / subtract modules. In one embodiment, the two add / subtract modules operate in parallel.

The invention discloses a Hadamard-transform near-infrared spectrograph added with a light harvesting structure, and relates to the field of Hadamard-transform near-infrared spectrographs. The spectrograph comprises a light source, the light harvesting structure consisting of a collimation lens and a cylindrical lens, a slit, a collimation lens, a plane grating, a DMD (digital micro mirror device), an imaging lens, a single-point detector, a static drive circuit and a spectral information acquisition and processing system. According to the Hadamard-transform near-infrared spectrograph, the light harvesting structure is added between an optical fiber and the slit, so that the energy utilization ratio of the system for light to be detected is improved greatly, and the detection for near-infrared spectrum is facilitated; appropriate slit width, grating incident angle and the like are selected, then the resolution ratio of the spectrograph is higher, simultaneously, the energy utilization ratio is higher, and the detection capacity of the spectrograph for a weak spectrum signal is improved; and a single-point photodiode is used to perform spectrum detection, accordingly, the spectrograph cost and the spectrograph size are reduced, and the detection sensitivity is improved.

The invention discloses an intra-frame 4*4 forecasting model selection method based on transform domain information, comprising the following steps of: (1) carrying out each-mode forecasting under intra-frame 16*16 and SATD (Sum of Absolute Transformed Difference) generation to a luminance macro block, selecting the mode with a minimum SATD value as the optimum forecasting mode under intra-frame 16*16 and obtaining the value of the optimum forecasting mode, when carrying out mode 2 SATD generation under intra-frame 16*16, modifying the traditional Hadamard transform processing method for each 4*4 subblocks, extracting the direction information of each 4*4 subblock from the intermediate result and then carrying out edge-direction histogram statistic to the direction information to obtain a candidate mode set, and only searching in the range of the candidate mode set when carrying out intra-frame 4*4 forecasting model selection; (2) respectively carrying out intra-frame 4*4 forecasting model selection to each the 4*4 subblock of the luminance macro block to obtain the optimum forecasting mode and the value of the luminance macro block under intra-frame 4*4; and (3) comparing the value of the optimum forecasting mode under intra-frame 16*16 with the value of the optimum forecasting mode under intra-frame 4*4 to select the optimum forecasting mode of the luminance macro block.

The invention discloses a method for embedding a digital watermark in a binary image. The method is as follows: part or all of the binary image is divided into at least two image blocks, and the first pixel is obtained according to the number of black pixels in each image block. A digital sequence; grouping the first digital sequence, performing Hadamard transformation on the data in each group to obtain a second digital sequence corresponding to each group; using a quantization method based on a quantization table, the watermark to be embedded Embedding the signal into the second digital sequence to obtain a third digital sequence; performing an inverse Hadamard transformation on the third digital sequence to obtain a fourth digital sequence, and determining the need to change the color in each image block according to the fourth digital sequence number of pixels, select a corresponding number of pixels in each image block, and change the color of the selected pixels. By adopting the invention, the image embedded with the watermark has a good visual effect and can resist printing, copying and scanning attacks.

Backscatter imaging using Hadamard transform masking includes an area x-ray source with alternating, masked, Hadamard transform patterns. The total backscatter signal from a target for each pair of corresponding masks is recorded. The difference in signal strengths for each pair of corresponding masks is a direct measurement of the Hadamard transform coefficient for that mask. An image of the target is formed by performing an inverse discrete Hadamard transform on the complete matrix of coefficients.

A method for decoding received data in a decoder which receives data from an encoder varying a length of a Walsh code according to a coding rate of transmission data, and has maximum IFHT (Inverse Fast Hadamard Transform) stages capable of decoding even the data encoded by a Walsh code with a maximum length. The method comprises selecting at least one IFHT stage among the maximum IFHT stages according to a length of the Walsh code used for the received data; and performing inverse fast Hadamard transform on the received data by the selected IFHT stage.

Interpreting data obtained by analysis of nucleic acids (DNA) by obtaining nucleic acid data in a spatial domain, transforming the nucleic acid data from the spatial domain into a frequency domain, and obtaining sequence data of the nucleic acid data by executing a data mining process on the transformed nucleic acid data. The transformation may be performed by a Hadamard transform, a Fourier transform or a Wavelet transform to obtain frequency coefficients, with less than all of the frequency coefficients being utilized in the data mining process. In addition, the frequency domain data may be normalized prior to the data mining process. The data mining process may be subjecting the frequency coefficients to a connectionist (neural network) algorithm or to a classification tree / rule induction (CART) algorithm.

The invention relates to a Hadamard transform imaging spectrometer, which overcomes the defects that after-treatment workload is large, the enhancement function on a certain characteristic spectral coverage cannot be realized, the coding precision is low, the volume is big and the requirements on processing and debugging are high in the prior art. The Hadamard transform imaging spectrometer comprises a preposed imaging system, a first collimating lens, a light-splitting device, a first convergent lens, a digital micromirror device, a second collimating lens, a light-converging device, a second convergent lens and an image surface detector; the preposed imaging system comprises a preposed imaging lens; the first collimating lens, the light-splitting device, the first convergent lens and the digital micromirror device form a light-splitting modulation system; the second collimating lens, the light-converging device, the second convergent lens and the image surface detector form a light-converging imaging system; and the composition of the first collimating lens is the same as that of the first convergent lens, and the composition of the second collimating lens is the same as that of the second convergent lens. The Hadamard transform imaging spectrometer has the advantages of small volume, high coding precision and the like.

The invention discloses a decision-making method and a decision-making method device for intra-frame prediction modes of high efficiency video coding. The decision-making method comprises the steps of: dividing directivity prediction modes of a current PU block into M direction mode groups according to corresponding serial number of the modes, and adopting a dichotomy to find out an optimal intra-frame prediction mode based on Hadamard transform at minimal rate distortion cost in each direction mode group; carrying out rough mode decision based on Hadamard transform on a mode 0, a mode 1, one or more most-likely prediction modes and the optimal intra-frame prediction mode in each direction mode group, and selecting the N intra-frame prediction modes based on Hadamard transform at minimal rate distortion cost to be added into a screening list; and carrying out rate distortion optimization calculation on the intra-frame prediction modes contained in the screening list, and selecting one of the optimal intra-frame prediction modes for predicting the current PU block. Compared with the prior art, the decision-making method and the decision-making method device can increase the intra-frame prediction encoding speed by 20% without changing video compression quality.

The present invention provides a method and apparatus that transforms input signals X0, X1, X2, X3 using a 4-point Hadamard transform matrix, and of the resulting transformation data, rounds up the LSB of the first transformed data and rounds down the LSB of the remaining odd-numbered data. When restoring the data to its original state the rounding is executed after a Hadamard inverse transformation is performed, thereby restoring the data to its original state X0, X1, X2, X3.

Embodiments of the invention compress ultrasound RF data after the receiver beamformer. An efficient compression algorithm is disclosed that incorporates the use of the Discrete Cosine Transform (DCT) and the Discrete Wavelet Packet (DWP) transform, followed by quantization of the wavelet coefficients. The algorithm first processes ultrasound scanlines from the receiver beamformer using a DCT transform. In a low-power configuration, a Hadamard transform may be used instead of the DCT. The output of the DCT processing is DCT coefficients at different frequencies. An optimized wavelet packet transform is then used for each coefficient line. The wavelet filter kernels and the wavelet packet trees can be jointly optimization using a two-step optimization algorithm.

The invention relates to a hadamard transform imaging spectrometer based on a bridge type grating light modulator, and the spectrometer provided by the invention can be applied to a linear array detector or single point detector. The hadamard transform imaging spectrometer comprises a receiving optical system, a chromatic dispersion element, an imaging mirror, a bridge type grating light modulator array, a focusing mirror and a detector, wherein the radiation information of a target is imaged on the chromatic dispersion element in lines by the receiving optical system according to different time sequences; after being split by the chromatic dispersion element, the radiation information is imaged on the programmable bridge type grating light modulator array by the imaging mirror; the bridge type grating light modulator array is programmed and driven according to a hadamard coding template, thereby allowing lights with different wavelengths to pass through in a manner of specific combination; the lights are focused on the detector by the focusing mirror; and finally, the space dimensional information and spectrum dimensional information of the target are acquired by performing the hadamard inverse transformation. The hadamard transform imaging spectrometer has the advantages of small volume, light weight, low cost, high speed and high signal to noise ratio. The hadamard transform imaging spectrometer can be widely applied to the fields of aerial remote sensing, industry, agriculture, biomedicine, matter analysis and classification, universal and astronomic surveillance, environment and disaster monitoring, atmospheric detection, searching and tracking for military targets, and the like.

The invention discloses a quick HEVC (High Efficiency Video Coding) inter-frame prediction mode selection method. After coarse selection of inter-frame prediction modes, the statistical property of Hadamard transform-based cost values corresponding to the coarsely selected inter-frame prediction modes is fully utilized, and the correlation of the video texture direction and an inter-frame prediction mode angle are fully considered; for prediction unit types of different sizes, the inter-frame prediction modes after the coarse selection are quickly screened through a threshold value method or the continuity of the coarsely selected inter-frame prediction modes is calculated to reflect the texture direction of the prediction unit, so that the unnecessary coarsely selected inter-frame prediction mode is screened without introducing more extra calculation; in a verification process of the most possible prediction mode, the correlation of the coarsely selected inter-frame prediction modes and the most possible prediction mode and the space correlation of a video image per se are fully considered, the final optimal inter-frame prediction mode is quickly obtained, and the inter-frame coding complexity is reduced on the premise that the video coding quality is guaranteed.

Blocks in two different frames are subjected to Hadamard transform by first and second Hadamard transform circuits, and a sum component and a difference component are calculated for the components of the two blocks corresponding to each other to perform three-dimensional Hadamard transform, so that detection is made as to whether or not these blocks include a motion. While the sum component and the difference component are encoded for the block determined as including a motion, a motion detection result, rather than the difference component, is encoded for the block determined as including no motion. As a result, a high compression ratio can be achieved in video encoding with a small-scale circuit.

The invention provides a high resolution spectrometer and an optical calibrating method thereof. The high resolution spectrometer is a hadamard transform spectrometer and comprises a light entrance port, a collimating lens, a grating, a first focusing lens, a digital micromirror, a second focusing lens and a detector according to the incident light sequence. A prism is arranged between the first focusing lens and the second focusing lens. The grating is an echelle grating. The digital micromirror is a two-dimensional digital micromirror. The spectrometer can be applied to spectral analysis.

Methods and apparatus for performing near lossless-concatenated N-level constrained quantization Hadamard transform decoding are provided. Accordingly, the present invention provides a transform-based coding technique, where the coding loss introduced during repeated encoding and decoding is reduced to a substantially insignificant level. This is accomplished by employing a constrained quantization and inverse quantization operation in each level of encoding / decoding in the decoder. In this manner, the concatenation error between each level of a decoder is reduced to a substantially minimum level and the quantization error introduced during quantization operations, i.e., originally at the encoder and in each level of the decoder, is substantially reduced. Thus, the decoded bit stream that is output at the N-th level of the decoder is substantially the same as the original bit stream provided to the input of the encoder.