77 results about "Inverse Laplace transform" patented technology

Presented herein are inverse scan, coefficient prediction, inverse quantization and inverse transform system(s) and method(s). In one embodiment, there is presented a system for converting scanned quantized frequency coefficients to pixel domain data. The system comprises a first circuit and a second circuit. The first circuit converts scanned quantized frequency coefficients to pixel domain data, wherein the scanned quantized frequency coefficients encode video data in accordance with a first encoding standard. The second circuit converts scanned quantized frequency coefficients to pixel domain data, wherein the scanned quantized frequency coefficients encode video data in accordance with a second encoding standard.

A seismic data set is processed by applying a transform to the seismic data set that corrects for time shifts in the seismic data set resulting from azimuthal variation. Alternatively, a seismic data set is sorted to common offset gathers. Then, the following steps are applied to each common offset gather: A transform is applied to the common offset gather that corrects for time shifts in the common offset gather resulting from azimuthal variation. The transformed common offset gather is inverse transformed.

The invention discloses a single-exposure high-dynamic range image generation method adapted to a medical image. The method comprises the steps that 1) images of different exposure are generated on the basis of reverse tone mapping, and a reverse tone mapping function is modeled; 2) according to a pseudo-exposure HDR image generated in the first step, a weight graph of the image is obtained on the basis of a pyramid decomposed multi-exposure image fusion algorithm; 3) Laplacian pyramid decomposition is carried out on a sequence of N multi-exposure images, Gaussian pyramid decomposition is carried out on N weight graphs, and images and weight graphs of different resolutions are obtained, and a fusion formula is obtained; and finally, Laplacian inverse transformation is carried out on a pyramid L{R}l to obtain a fused image R. Thus, an HDR image synthesized by input image is obtained. Compared with an original image, the synthesized HDR image is higher in contrast, more distinct in colors, and more reinforced in details; a fusion algorithm is low in computational complexity; and high dynamic range image generation can be realized in real time.

The invention provides a time-frequency transform based method for identifying parameters of a synchronous generator. The method includes steps of S1. carrying out Laplace transform on a differential equation of a d axle and a q axle of a generator in time domain in a generator model to obtain an equation of the d axle and the q axle of the generator in frequency domain, and carrying out inverse Laplace transform to obtain an integral equation of the d axle and the q axle of the generator in the time domain; S. replacing state variable of the integral equation of the d axle and the q axle of the generator in the time domain; S3. dispersing the integral equation of the d axle and the q axle of the generator in the time domain into that measurable column vectors or integration of the measurable column vectors are equal to a matrix multiplying by column vectors of coefficients of the integration equation, and solving to obtain the column vectors of the coefficients of the integration equation; and S4. solving to obtain parameters of the generator model according to the relation between the column vectors of the coefficients of the integration equation and parameters of the generator. A differential equation of a generator is converted to an integration equation according to the time-frequency transform based method for identifying the parameters of the synchronous generator, stability of calculating a value is facilitated, and the problem of an unstable identification result is solved.

The invention relates to a contrast enhancement method based on wavelet transform image decomposition and belongs to the field of image processing and computer vision detection. The method firstly separates high and low frequency information of an image with nonuniform light bar brightness by wavelet transform, and then removes the noise of high-frequency information by a wavelet transform multi-scale threshold denoising method, enhances the contrast of low-frequency information by a contrast restriction adaptive histogram equalization method, and finally, obtains an enhanced image by inverse wavelet transform. The method processes high and low frequency information respectively by using wavelet transform and the contrast restriction adaptive histogram equalization method, removes the noise to a great extent, enhances signal intensity and effectively improves the uniform uniformity of the light bars.

The invention belongs to the technical field of microwave remote sensing and probing, and discloses a two-dimensional radial imaging method. An imaging system consists of an antenna array and two reflecting surfaces. By measuring related output of all antennas, the cosine visibility is solved by solving linear equations associated with the related output and the cosine visibility, and then brightness and temperature distribution of a scene is reestablished by inverse cosine transform. By the imaging method, high system resolution can be obtained by using a small number of antennas and a simple receiver structure.

Methods and systems for image and video enhancement and data-loss recovery using wavelet transforms are disclosed. A wavelet transformed image is defined as multiple sections, where one section is the original image, and coefficients are estimated for each other section using information obtained from that section. An inverse wavelet transform on the wavelet transformed image obtains an enlarged image. For obtaining a high resolution video frame, one section is the original video frame, and coefficients are estimated for each other section using information from a lower level wavelet transform of a corresponding section of a past or future frame of the video sequence. For recovery of data lost from transmitted original data, the locality of the lost data is determined in lower and higher levels of a wavelet transform tree, and information at the locality in the lower and higher levels is used to estimate the lost data.

This invention solves problems due to employing error degraded data in digital processing. It particularly solves multi-generation problems wherein transform data degrade during each inverse transform and forward transform cycle even without any processing due to the rounding and clipping errors. It provides methods, systems and devices for reduced-error processing of transform-coded data. After inverse transformation of transform data, high-precision numbers are manipulated. The converting to integers and clipping to an allowed range steps are executed at any stage in the manipulation to obtain integer representation of the inverse transformed data such as for displaying of the data. However, further processing including forward transforming back to the transform domain is executed on the high-precision numbers. Thus, the rounding and clipping errors are not present in the processed data. Although advantageous to many applications employing digital transformed data, the invention is particularly advantageous for use in digital studios during editing of MPEG-coded, JPEG-coded and wavelet-coded video and audio data.

Methods and associated apparatuses for imaging a target. An echo sequence image of the target is acquired and a log spectrum of at least a portion of the echo sequence image is computed. A point spread function is estimated by one of two methods. According to the first method, a low-resolution wavelet projection of the echo sequence log spectrum is used as an estimate of the log spectrum of the point spread function. According to the second method, an outlier-resistant wavelet transform of the echo sequence log spectrum is effected, followed by soft-thresholding and an inverse wavelet transform. Under both methods, a frequency domain phase of the point spread function also is estimated, the relevant portion of the echo sequence image is deconvolved using the estimated point spread function.

At least the deviation on a pixel having a value deviating from a predetermined range through inverse transform of image data from a frequency domain is reduced, wherein a pixel which should have a value changed in a direction reverse to the deviation is determined based on a character of the inverse transform.

A circuit compensating for the difference in transmission rate of digital samples generated in transmit and receive paths between a user and a transceiver processing in the frequency domain, such as a digital multi-tone (DMT) transceiver. Compensation of the DMT transmission rate in the receive path in accordance with exemplary embodiments of the present employs zero-padding of the frequency domain coefficients generated by the DMT transceiver prior to applying an inverse transform, such as the inverse fast Fourier transform (IFFT). Zero-padding the frequency domain coefficients allows for the compensation of the transmission rate in the receive path by generating digital samples from the frequency domain coefficients with an inverse transform having a rate matched to the frequency domain transform and rate employed in the transmit path.

An NMR measurement method adapted for measurements on solid mixture samples starts with irradiating a pulse sequence to the sample in order to measure the longitudinal magnetization relaxation times of nuclei possessing homogeneous longitudinal magnetization relaxation times (step 1). After a lapse of a given period of time t, a high-resolution NMR spectrum is acquired by nullifying spin diffusion across the nuclei (step 2). The steps 1 and 2 are repeated while varying the period of time t. The high-resolution NMR spectra are classified according to value of longitudinal magnetization relaxation time by inverse Laplace transform.

The invention discloses a harmonic noise suppression method based on waveform morphology sparse modeling. The harmonic noise suppression method includes the steps of 1) constructing Chirplet transform according to waveform morphological characteristics of harmonic noise in seismic records acquired via vibroseis slip sweep, and constituting an over-complete dictionary with continuous wavelet transform; 2) quickly implementing Chirplet positive and inverse transforms; 3) determining Chirplet transform parameters based on time-frequency distribution characteristics of correlated data; and 4) according to the starting frequency of a reference scanning signal, determining the filter cutoff frequency of the harmonic noise to achieve fidelity separation of an effective signal from the harmonic noise. The invention solves the problem of harmonic noise interference in the seismic data acquired via vibroseis slip sweep, and achieves the purpose of improving the signal-to-noise ratio of the seismic data. The method of the invention determines the Chirplet transform according to the time-frequency distribution characteristics of the harmonic noise, and ensures the sparseness; the fast implementation of the Chirplet transform guarantees the efficiency of transform, and the correction coefficient guarantees the accuracy of inverse transform reconstruction; and the Chirplet transform parameters are automatically determined according to the data drive, a strong adaptability is gained and single-channel calculation facilitates parallel processing.

A low complexity video decoder includes: a fast variable length decoding (VLD) and inverse quantization module arranged to perform fast VLD and inverse quantization on an input bit stream to generate inverse quantization results; an inverse transform unit arranged to perform inverse transform on the inverse quantization results to generate inverse transform results; a motion compensation module arranged to perform motion compensation according to the input bit stream and generate associated prediction outputs; an arithmetic unit arranged to sum up the inverse transform results and the prediction outputs to generate compensated outputs; a reconstructed frame output unit arranged to generate reconstructed frames according to the compensated outputs; and a frame storage arranged to store some reconstructed frames. The low complexity video decoder operates in accordance with a resolution of the reconstructed frames, rather than a resolution of a plurality of original frames represented bythe input bit stream.

The invention provides an aircraft power supply system safety analysis method based on combined fault tree and Markov. The method comprises the following steps: establishing a dynamic fault tree modelof an aircraft power supply system according to the structure of the aircraft power supply system; determining a state transition diagram of a Markov model of the aircraft power supply system; determining a state transition probability formula according to the operating principle of the aircraft power supply system and an internal logical relation; establishing a state transition matrix and a corresponding differential equation; transforming the linear system of equations; and solving the linear system of equations, and performing inverse Laplace transform so as to obtain a dynamic fault probability function of the aircraft power supply system, and analyzing the safety of the aircraft power supply system. The method disclosed by the invention has the beneficial effects that the aircraft power supply system can be maintained in corresponding time periods, and the failure probability of the aircraft is greatly reduced; and the method can also be applied to safety analysis of other aircraft types or other systems, and provides reference for reliability analysis and study of each system of the aircraft.

A fast implementation of the 8-point WMV9 / VC-9 transform is realized using a sequence of butterfly operations and matrix multiplies. A fast implementation of the inverse transform is realized by applying inverses of the butterfly operations with the matrix multiplies in reverse flow. These fast implementations permit scaling to be incorporated into the transform stages either at the end of both dimensions of filtering, or separately at each stage. These fast implementations of the transform can be used in encoders and decoders based on this transform in image compression and other signal processing systems.

This invention solves problems due to employing error degraded data in digital processing. It particularly solves multi-generation problems wherein transform data degrade during each inverse transform and forward transform cycle even without any processing due to the rounding and clipping errors. It provides methods, systems and devices for reduced-error processing of transform-coded data. After inverse transformation of transform data, high-precision numbers are manipulated. The converting to integers and clipping to an allowed range steps are executed at any stage in the manipulation to obtain integer representation of the inverse transformed data such as for displaying of the data. However, further processing including forward transforming back to the transform domain is executed on the high-precision numbers. Thus, the rounding and clipping errors are not present in the processed data. Although advantageous to many applications employing digital transformed data, the invention is particularly advantageous for use in digital studios during editing of MPEG-coded, JPEG-coded and wavelet-coded video and audio data.

A table forming unit calculates, in a weighted reproducing kernel Hilbert space formed of an absolutely continuous function that is zero at an origin, solutions of simultaneous equations obtained by discretization of an integral equation of the second kind derived from Tikhonov regularization method with a weighted square integrable space used as an observation space, and forms an H table describing information including numerical solution of the integral equation of the second kind based on the solutions of the simultaneous equations. An inverse transform unit obtains, by numerical calculation, an inner product, in the weighted square integrable space, of the numerical solution of the integral equation of the second kind and a Laplace transform image multiplied by a mollifier function with reference to the H table.

A wavelet transform is applied to successive images of a video sequence to obtain wavelet coefficients for each image, and directions of regularity are estimated in association with the wavelet coefficients. Recursive weights are also determined to be associated with the wavelet coefficients. An average multiscale bandlet coefficient associated with a wavelet coefficient for a current image is computed from this wavelet coefficient, the recursive weight associated therewith and a corresponding average multiscale bandlet coefficient computed for a previous image and associated with a wavelet coefficient offset according to the direction of regularity associated with the wavelet coefficient. The average multiscale bandlet coefficients can then be processed to produce an enhanced bandlet image to which an inverse wavelet transform is applied. The determination of a recursive weight associated with a wavelet coefficient for the current image comprises checking a condition between this wavelet coefficient and the corresponding average multiscale bandlet coefficient computed for the previous image, and updating a value of the recursive weight depending on the condition.

The invention discloses a fusion method for a multispectral image and a panchromatic satellite image. The method includes: respectively extracting SIFT feature points of the multispectral image and the panchromatic satellite image, and performing dimension reduction processing; performing rough matching and mismatching removal of the SIFT feature points after dimension reduction processing by employing a BBF algorithm, and performing accurate matching by employing affine transformation; performing HIS transformation of the multispectral image after accurate matching, obtaining components of brightness, saturation, and chromaticity, respectively performing wavelet transform of the brightness component and a histogram of the panchromatic satellite image, performing high-frequency replacement and inverse wavelet transform of wavelet transform results of the brightness component and the histogram in sequence, and obtaining a new brightness component; and updating the new brightness component via preset parameters, and performing HIS inverse transformation of the updated brightness component, the saturation component, and the chromaticity component in order to realize image fusion. According to the method, accurate and effective registration of the panchromatic satellite image and the multispectral image can be realized, and the fusion image is effectively obtained.

The present invention provides a reservoir irreducible water saturation determining method and device. The method includes the following steps that: an exponential hyperbolic sine function is constructed, and Laplace transformation is performed on the exponential hyperbolic sine function, so that a progressive step function can be obtained; an unknown parameter in the exponential hyperbolic sine function is solved according to a special value condition which the progressive step function satisfies, and the constructed exponential hyperbolic sine function is updated according to the solved unknown parameter; integral transformation is performed on acquired nuclear magnetic resonance echo data according to the updated exponential hyperbolic sine function, and reservoir irreducible water saturation can be determined. According to the method and device provided by the invention, inverse Laplace transformation for inversion is not required to be performed on the nuclear magnetic resonance echo data, uncertainties caused by the inversion can be avoided; and accurate irreducible water saturation can be obtained under a condition that the signal noise ratio of the nuclear magnetic resonance echo data is low.

The invention discloses a method for solving the analytical solution of confined aquifer seepage flow of a single well circulation system, which comprises the following steps of: establishing a mathematical model of the confined aquifer of the single well circulation system; Determining a governing equation of groundwater flow in the confined aquifer mathematical model and a boundary condition inthe confined aquifer mathematical model; Applying a Laplace transform to derive a governing equation of groundwater flow in the confined aquifer mathematical model in the Laplace domain and boundary conditions in the confined aquifer mathematical model in the Laplace domain; obtaining the seepage analytical solution of the confined aquifer mathematical model in the Laplace domain by using the method of separating variables and Fourier series continuation of the boundary condition around the well; and obtaining the seepage analytical solution of the confined aquifer mathematical model in the Laplace domain; using an inverse Laplace transform to obtain an analytical solution of the seepage flow of the confined aquifer mathematical model. The analytical solution of the confined aquifer seepage flow of the single-well circulation system obtained by the invention lays an important foundation for further solving the heat transfer mechanism and the temperature field change of the single-wellcirculation system aquifer.

The invention provides a two-dimensional discrete inverse wavelet transform device applied to a JPEG 2000 decoder, and relates to the two-dimensional discrete inverse wavelet transform device. The two-dimensional discrete inverse wavelet transform device aims to solve the problems that the inverse wavelet transform hardware part applied in the JPEG 2000 decoder is low in speed and high in storage. The two-dimensional discrete inverse wavelet transform device comprises a wavelet coefficient memory, a read address generating module, a column inverse transform module, a Reg rearrangement module, a row inverse transform module, a writing address generating module and an IDWT control module. The wavelet coefficients after being subjected to two-dimensional interleaving are stored in the wavelet coefficient memory, the read address generating module reads the wavelet coefficients through the method that the two columns scan alternately and a Z-shaped method and the writing address generating module writes the wavelet coefficients through the method that the two columns scan alternately and the Z-shaped method, the column inverse transform module finishes one-dimensional discrete inverse wavelet transform in the vertical direction, the row inverse transform module finishes one-dimensional discrete inverse wavelet transform in the horizontal direction, data rearrangement between column inverse transform and row inverse transform is achieved through the Reg rearrangement module, and the IDWT control module controls other modules to finish inverse wavelet transform. The two-dimensional discrete inverse wavelet transform device is applied to the JPEG 2000 decoder.

A system for decoding video including receiving quantized coefficients representative of a block of video representative of a plurality of pixels and dequantizing the quantized coefficients. The system inverse transform the dequantized coefficients using a first one dimensional inverse transform and a second one dimensional inverse transform to determine a decoded residue where the result of the first one-dimensional inverse transform are shifted different amounts using a shifting process based upon the magnitude of the dequantized coefficients.

The invention relates to a the field of automatic optical detection technology of TFT-LCD panels, and particularly relates to a method and a device for carrying out two-dimensional Fourier transform and inverse transform on an image. The method comprises the following steps: extracting a row of picture data from an A area of an external memory at one time, carrying out one-dimensional Fourier transform and inverse transform, and storing operation results in a B area of the external memory in sequence, until the one-dimensional Fourier transform and inverse transform of the entire picture is finished; partitioning the image data in the B area of the external memory, extracting an image from the B area of the external memory according to a row direction at each time, storing the image in a random memory, overturning the interiors of the image blocks, and writing the image blocks in the A area of the external memory according to a column direction in sequence; and repeating the process until the two-dimensional Fourier transform and inverse transform of the entire picture is finished. The image blocks are overturned and are the interiors of the image blocks overturned, so FPGA resource consumption is few, and image data reading and writing efficiency is high.

The invention relates to an adaptive enhancement method of brain magnetic resonance volumetric data based on transformed domain HMT model , belonging to the field of medical image processing. The method organically combines wavelet transform and hidden Markov chain. According to the characteristics of non-Gaussian distribution with long tail and high peak value of the probability density functionof single wavelet coefficients, a Gaussian mixture model is established for the randomness of single wavelet coefficients. At the same time, the persistence of wavelet coefficients is described by Hidden Markov Tree (HMT). The wavelet domain Hidden Markov Tree model is established and the EM algorithm is used to solve the model. Using the solution of HMT model, the expectation of wavelet coefficients is estimated in the absence of noise. The inverse wavelet transform of the noise suppressed wavelet coefficients is used to obtain the enhanced MRI volume data. Through subjective and objective evaluation, the wavelet adaptive enhancement method has better visual information fidelity than wavelet threshold enhancement method.

The present invention provides an electromagnetic wave / particle beam spectroscopic instrument that is not easily deteriorated in spectroscopic capability, and is resistant to electromagnetic noise, vibrations, heavy sound, heat and specific particle beams of interest, particle beams other than electromagnetic waves, electric noise due to electromagnetic waves, mechanical destruction, and recoiling of solid constituent atoms and is also more resistant to radiation exposure on the detection means than the conventional energy resolving technologies. A spectroscopic instrument 10 includes a Laplace transform filter 11 that performs Laplace transform on the intensity of an incident spectrum, a detection element 15 that detects a transmitted intensity of the incident spectrum, and an arithmetic device 17 that performs inverse Laplace transform on the detected transmitted intensity of the incident spectrum, thereby calculating the incident intensity of the incident spectrum that has entered the Laplace transform filter 11.

The invention discloses an acceleration method for realizing inverse wavelet transform in an JPEG2000 decompression algorithm by using a GPU. The method comprises the following steps: firstly, performing optimized storage for inverse wavelet transform coefficients in a shard memory by using the advantage that the GPU shared memory is high in access speed; and secondly, adopting a parallel processing mode that one block processes a line (column) of pixels according to the characteristics that the line-line processing and column-column processing in the inverse wavelet transform process are independent of each other, adopting a parallel processing mode that one thread processes a plurality of pixels according to the characteristics that the processing of the same line (column) of pixels has dependence, but part of the processing procedure can still be parallel, and completing the inverse wavelet transform in a horizontal direction and a vertical direction. According to the inverse wavelet transform acceleration method disclosed by the invention, the advantages that the GPU has a large number of cores and is suitable for parallel computation are fully used, and the decompression speed of JEPG2000 can be improved effectively; and moreover, the algorithm structure is simple and reasonable, and is easy to implement on the GPU.

The embodiment of the invention discloses a damping configuration method and device for a virtual synchronous machine, and the method comprises the steps: building a second-order switching period meanmodel of the virtual synchronous machine, and obtaining a first small signal model of an output current of the virtual synchronous machine, a small signal expression of output active power and a second small signal model of a swinging equation and a power angle equation; calculating a fourth-order function of output active power variation to load-side frequency variation according to the small signal expression, the first small signal model and the second small signal model; carrying out the inverse Laplace transformation of the fourth-order function during the jumping of the load-side frequency to obtain a response function of output active function; and solving extreme values of the response function to obtain a maximum value expression of the output active power. The method provided bythe invention is clear and effective, and brings convenience to the people for configuring damping of the virtual synchronous machine.