67 results about "Discrete sine transform" patented technology

Calculate the log frame energy value of each of a pre-determined number n of frames of an input speech signal and apply a matrix transform to the n log frame energy values to form a temporal matrix representing the input speech signal. The matrix transform may be a discrete cosine transform.

Provided is an apparatus and method for encoding and decoding using alternative transform units according to the correlation of residual signals. The video encoding apparatus includes a first transforming unit for performing discrete cosine transform (DCT), first quantization, first inverse quantization, and inverse DCT on a block basis onto residual coefficients generated after intra frame prediction or inter frame prediction; a second transforming unit for performing discrete sine transform (DST), second quantization, second inverse quantization, and inverse DST on a block basis onto the residual coefficients; a selecting unit for selecting one having a high compression rate between the first and second transforming units for each block through performing rate-distortion optimization; and a flag marking unit for recording information about the selected transforming unit at a flag bit provided on a macroblock basis.

An image encoding apparatus for application to images expressed as respective frames of a digital video signal, whereby an image is converted into an array of blocks with specific blocks predetermined as being independent internally encoded blocks and the remainder as predictively encoded blocks, with predicted pixel signal values for a predictively encoded block being derived by interpolation from pixel signal values of at least one pair of blocks which have been already encoded and enclose that predictively encoded block along the row or column directions or both the row and column directions. Encoding efficiency is enhanced by applying Discrete Sine Transform processing along the interpolation direction, when encoding an array of prediction error signal values derived for a block, and by executing adaptive prediction by determining an optimum interpolation direction, when there are two possible directions for deriving predicted pixel signal values for a block.

The invention provides an optimized video data coding method based on boundary adaptive transform. The method mainly comprises steps: according to the existing DCT (Discrete Cosine Transform) matrix for video coding, a new transform matrix is generated, the new transform matrix and the existing DST (Discrete Sine Transform) / DCT matrix are combined into a new transform matrix set; according to a prediction mode, the size of a transform unit, and the relationship between the boundary information of a transform unit and the boundary information of a prediction unit, a group of transform matrixes is selected from the new transform matrix set; and by using the group of new transform matrixes, inputted video data are transformed, and a coding stream is generated. The method of the invention makes full use of distribution characteristics of residual matrixes after inter-frame prediction, and based on the boundary information of the prediction unit and the transform unit, a different transform matrix is adopted for a different boundary characteristic to carry out transform. The optimized method can select a more efficient transform matrix for transform in a targeted mode according to the characteristics of residuals after inter-frame prediction, and the coding efficiency is thus improved.

The present invention relates to a method and apparatus for encoding and decoding a video image based on transform. The method for decoding a video includes: determining a transform mode of a current block; inverse-transforming residual data of the current block according to the transform mode of the current block; and rearranging the inverse-transformed residual data of the current block according to the transform mode of the current block, wherein the transform mode includes at least one of SDST (Shuffling Discrete Sine Transform), SDCT (Shuffling Discrete cosine Transform), DST (Discrete Sine Transform) or DCT (Discrete Cosine Transform).

The present invention relates to a method and an apparatus for transform-based image encoding / decoding. The image decoding method according to the present invention comprises: a step of determining atransform mode of a current block; a step of inversely transforming residual data of the current block according to the transform mode of the current block; and a step of rearranging the residual dataof the current block inversely transformed according to the transform mode of the current block, wherein the transform mode may include at least one of a shuffling discrete sine transform (SDST), a shuffling discrete cosine transform (SDCT), a discrete sine transform (DST) and a discrete cosine transform (DCT).

A system and method for parallel computation of Discrete Sine and Cosine Transforms. The computing system includes a plurality of interconnected processors and corresponding local memories. An input signal x is received, partitioned into P local vectors xi, and distributed to the local memories. The preprocessors may calculate a set of coefficients for use in computing the transform. The processors perform a preprocess in parallel on the input signal x to generate an intermediate vector y. The processors then perform a Fast Fourier Transform in parallel on the intermediate vector y, generating a second intermediate vector a. Finally, the processors perform a post-process on the second intermediate vector a, generating a result vector v, the Discrete Transform of signal x. In one embodiment, the method generates the Discrete Sine Transform of the input signal x. In another embodiment, the method generates the Discrete Cosine Transform of the input signal x.

Systems and methods for robust recognition of machine-readable symbols from highly blurred or distorted images. An image signal representation of a machine-readable symbol element is transformed into a different space using one or more transform operations, which moves an n-dimensional vector of measured light intensities into another n-dimensional space. The types of transform operations may include blur robust orthonormal bases, such as the Discrete Sine Transform, the Discrete Cosine Transform, the Chebyshev Transform, and the Lagrange Transform. A trained classifier (e.g., an artificial intelligence machine learning algorithm) may be used to classify the transformed signal in the transformed space. The types of trainable classifiers that may be used include random forest classifiers, Mahalanobis classifiers, support vector machines, and classification or regression trees.

The invention discloses a method for built-in steganography of an H.265 video. Information embedding is carried out for the DST (Discrete Sine Transform) coefficient of a 4*4 luminance residual block. First, two directions of distortion drift are determined according to the intra-frame prediction mode of an H.265 video. Then, a triple of a corresponding format is selected for information embedding according to the specific direction of distortion drift. As the triple used has a coefficient compensation effect, 4*4 luminance block pixels causing distortion drift do not change during inverse transformation of the embedded DST coefficient of the residual block, and the purpose of distortion drift control during built-in steganography is achieved. Experimental results show that the method for built-in steganography of an H.265 video provided by the invention can effectively control intra-frame distortion drift, and has good visual imperceptibility and a good visual effect.

A more efficient encoder / decoder is provided in which an N-point MDCT transform is mapped into smaller sized N / 2-point DCT-IV, DST-IV and / or DCT-II transforms. The MDCT may be systematically decimated by factor of 2 by utilizing a uniformly scaled 5-point DCT-II core function as opposed to the DCT-IV or FFT cores used in many existing MDCT designs in audio codecs. Various transform factorizations of the 5-point transforms may be implemented to more efficiently implement a transform.

An image encoding apparatus for application to images expressed as respective frames of a digital video signal, whereby an image is converted into an array of blocks with specific blocks predetermined as being independent internally encoded blocks (D) and the remainder as predictively encoded blocks (A, B, C), with predicted pixel signal values for a predictively encoded block being derived by interpolation from pixel signal values of at least one pair of blocks which have been already encoded and enclose that predictively encoded block along the row or column direction or both the row and column directions. Encoding efficiency is enhanced by applying Discrete Sine Transform processing along the interpolation direction, when encoding an array of prediction error signal values derived for a block, and by executing adaptive prediction by determining an optimum interpolation direction, when there are two possible directions for deriving predicted pixel signal values for a block.

The invention discloses a SPEED fast magnetic resonance imaging method based on discrete cosine transform. The SPEED fast magnetic resonance imaging method based on discrete cosine transform mainly includes the steps of k space data collection, zero fill Fourier reestablishment, discrete cosine transform, discrete cosine transform domain double-layer sparse ghost model determining, overlapped ghost separation based on LSE, discrete cosine inverse transformation, registering and summation of a plurality of ghost sub-images and image reconstruction. By means of the SPEED fast magnetic resonance imaging method, discrete cosine transform can be used for SPEED data sparse representation and improve image sparseness, and accordingly quality of a SPEED reconstructed image is improved.

The invention relates to an encryption algorithm of encryption OFDM (Orthogonal Frequency Division Multiplexing) based on discrete Hartley transform, and belongs to the technical fields of information communication and signal processing. Compared with the conventional OFDM system, an IFFT (Inverse Fast Fourier Transform) module which is necessary in an OFDM system is omitted, and the complexity of the system is reduced. At the same time, the diversity gain of frequency selectivity of the system is increased, and the anti-fading performance and the capacity of the system are improved.

The invention belongs to the field of nuclear detection processing in nuclear technique exploration, in particular to a discrete cosine neural-network fuzzy noise reduction method for nuclear detection data, and aims to effectively reduce noise in gamma spectrum data. The method includes the steps: subjecting spatial data formed by nuclear detection signal data to discrete cosine transform to obtain frequency spectrum data in a discrete cosine domain; subjecting the nuclear detection data to filtering and inverse discrete cosine transform in the discrete cosine domain to obtain primary noise reduction result; establishing a neural network, inputting a sample by using the nuclear detection signal data as nodes in the neural network, and estimating parameters of a membership function in the neutral network by means of least squares back-propagation to obtain final noise reduction result output by the neural network. The method is capable of well recognizing noise signals, network model parameters are regulated and optimized according to noise signal features, the noise in the signal data is reduced effectively, and signal-to-noise ratio of the nuclear detection data is increased greatly.

The invention relates to a method for coding and rebuilding an image block in video coding. A coding process comprises the following steps of: generating an image prediction block according to a prediction mode selected by a current block; selecting a group of low-complexity integer DST (Discrete Sine Transform) functions to transform a residual block so as to obtain a transformation ratio block; and quantizing the transformation ratio block. A rebuilding process comprises the following steps of: receiving the quantized transformation ratio block; carrying out inverse quantization to obtain a transformation ratio block; selecting a group of low-complexity integer DST functions to inverse transform the transformation ratio block; calculating to obtain a residual block; generating an image prediction block according to a prediction mode selected by a current block; and combining with the residual block calculated through inverse transformation to generate a rebuilt image block. According to the method, DST without multiplication is realized, has approximately the same performances as those of MDDT (Mode-dependent Directional Transform), but the storage complexity of a coder and a decoder is obviously reduced, so the method can be directly applied in a video coding process, so that the coding efficiency is effectively improved, and the computation complexity of relevant mode transformation is reduced.

A method of controlling residual coding for decoding or encoding of a video sequence, is performed by at least one processor and includes determining whether a small transform size of a primary transform is to be used for the residual coding of a coded block of the video sequence. The method further includes based on the small transform size of the primary transform being determined to be used, identifying, as the primary transform, a first transform set including discrete sine transform (DST)-4 and discrete cosine transform (DCT)-4, based on the small transform size of the primary transform being determined to not be used, identifying, as the primary transform, a second transform set including DST-7 and DCT-8, and performing the residual coding of the coded block, using the identified primary transform.

The invention discloses a discrete cosine interpolation method in channel estimation based on pilot frequency aiming at the problem that the traditional DCT (Discrete Cosine Transform) interpolation algorithm is not based on the widely used DCT II and can not use continuously the traditional DCT rapid algorithm for interpolation. The interpolation is carried out by using the DCT II, and rapid calculation is carried out by adopting rapid Fourier, thus the invention can be widely applied to communication systems and digital signal processing.

The invention discloses a self-embedded full-blind color image robust watermarking method based on multiple transform domains. The method comprises the following steps of: performing fast finite shearwave transformation on a blue part of an original color image, and generating an original characteristic watermark for copyright protection based on QR decomposition and one-dimensional discrete sinetransformation in a transformed low-frequency sub-band by virtue of a'zero watermark 'thought; and then performing dual-density dual-tree complex wavelet transform on the green part of the original color image, and completing embedding of the original feature watermark in the obtained low-frequency sub-band based on two-dimensional discrete sine transform and a pre-generated random number pair. The watermark embedding end does not need to select additional information as a watermark, and the watermark detection end can carry out copyright recognition on a color image in a'full-blind 'manner only by means of an attacked image and a related secret key. The method has good watermark invisibility, and the generation and self-embedding scheme of the original feature watermark can effectively resist various common attacks.

A method and apparatus of adaptive image and video coding including an alternative transform other than the discrete cosine transform (DCT) and discrete sine transform (DST) type VII (DST-VII) are disclosed. For at least one block size belonging to the size group, a transform from multiple transforms comprising an alternative transform in addition to DCT and DST-VII is selected and applied to a current block. The alternative transform may correspond to DCT type IV (DCT-IV) or DST type IV (DST-IV).

A method and system may identify a video data block using a video codec and apply a transform kernel of a butterfly asymmetric discrete sine transform (ADST) to the video data block in a pipeline.

According to the invention, the multi-mode time-frequency domain conversion and the deep learning technology are combined, and a multi-component mixed Raman spectrum unmixing method is developed, so that clinical in-vivo and in-situ detection and disease diagnosis of novel Raman probes, instruments and the like are facilitated. The method comprises the following steps: (1) converting a mixed Raman spectrum from a time domain to a frequency domain by using fast Fourier transform (FFT), discrete cosine transform (DCT) and discrete sine transform (DST), and extracting frequency domain features; (2) extracting multi-scale local time-frequency domain characteristics of the mixed spectrum by using short-time Fourier transform (STFT) and discrete wavelet transform (DWT); (3) carrying out spectral unmixing calculation in each mode in combination with a one-dimensional attention mechanism U-shaped neural network model; and (4) fusing various modal unmixing results by using a meta-learning method, and analyzing the weight of each modal to obtain an accurate unmixing spectrum. Compared with a traditional Raman spectrum analysis method, the Raman spectrum multi-component signal unmixing method based on multi-modal time-frequency domain transformation and deep learning can accurately separate independent Raman signals of different tissue structures and biochemical components in a complex environment in a living body, so that the unmixing accuracy of the Raman spectrum multi-component signal is improved. Therefore, convenience is provided for subsequent disease mechanism analysis and diagnosis. The method provides an innovative and potential solution for in-vivo and in-situ detection analysis and disease diagnosis of medical clinical Raman spectroscopy.

A circuit for performing a discrete cosine transformation (DCT) of input signals (416) includes a forward adder-tree module (402), a first set of multiplexers (404), a shared flow-graph module (406), an inverse adder-tree module (408), and a second set of multiplexers (410) coupled in series. In operation, the multiplexers (404) are configured to process input signals via the forward adder-tree module (402) and the shared flow-graph module (406) to perform a forward DCT of the input signals (416) or via the shared flow-graph module (406) and the inverse adder-tree module (408) to perform an inverse DCT of the input signals (416).

The invention relates to a multichannel sound signal coding and decoding method and device. The coding method includes: using modified discrete cosine transform (MDCT) or modified discrete sine transform (MDST) to map first multichannel sound signals into first frequency domain signals; dividing the first frequency domain signals into different time frequency sub-bands; in each time frequency sub-band, calculating the first statistical properties of the first multichannel sound signals; estimating a principal component analysis (PCA) mapping model according to the first statistical properties; using the PCA mapping model to map the first multichannel sound signals into second multichannel sound signals; perceptually coding at least one group of second multichannel sound signals and the PCA mapping model according to the differences in time, frequency and channel to obtain coded multichannel code streams. The coding method has the advantages that the MDCT or MDST is used to perform time frequency mapping, the PCA mapping model is specifically estimated according to the statistical properties, and high coding efficiency and quality are achieved.

A method and apparatus for fast inverse discrete cosine transform (IDCT) are provided. The fast IDCT method includes: (a) searching all elements of a discrete cosine transform (DCT) matrix in a predetermined order for non-zero elements; and (b) calculating the restored value of each element of a restoration matrix, by 2 dimensional-inverse DCT (2D-IDCT) transforming the non-zero elements of the DCT matrix by using the symmetry of an IDCT formula. According to the method and apparatus, unnecessary computation for 0's that are the majority of elements in a DCT matrix can be reduced to the minimum in performing the IDCT transform. In addition, even when the number of elements having effective values is large in a DCT matrix, the amount of computation is greatly reduced by using the symmetry of a DCT formula such that the method shows an excellent performance when statistically compared to the conventional fast DCT algorithms.

The invention discloses a rice pest intelligent recognition and classification method based on principal component analysis. According to the method, discrete sine transform (DST) and modular 2-dimension principal component analysis (modular 2D PCA) are combined to achieve rice pest image intelligent recognition. The method includes the steps that firstly, rice pest images are subjected to the DST and then are compressed, IDST is performed on the images to reestablish images to filter out high-frequency parts insensitive to human eyes; secondly, rice pest feature extraction and mode recognition are performed through the modular 2D PCA method. Accordingly, the method plays an important role in reducing feature dimensions and maintaining illumination, colors, gestures and other insensitive classification features. According to the rice pest intelligent recognition and classification system, images shot by digital cameras can be applied to computer programs to be processed, unknown pest images can be automatically compared with training sample database pest images in a data storer through Matlab software, and then recognition results can be output to a display.

A multichannel acoustic signal encoding method, decoding method and device, the encoding method comprising: employing a modified discrete cosine transform (MDCT) or a modified discrete sine transform (MDST) to map a first multichannel acoustic signal as a first frequency domain signal (101); dividing the first frequency domain signal into different time frequency sub-bands (102); calculating a first statistical characteristic of the first multichannel acoustic signal in each time frequency sub-band (103); estimating a principal component analysis (PCA) mapping model according to the first statistical characteristic (104); employing the PCA mapping model to map the first multichannel acoustic signal as a second multichannel acoustic signal (105); and according to differences in time, frequency and channel, conducting perceptual encoding on the PCA mapping model and at least one group in the second multichannel acoustic signal to obtain an encoding multichannel code stream (106). Thus, the encoding method employs an MDCT or an MDST to conduct time frequency mapping, estimates the mapping model according to the statistical characteristic, and selects the specific PCA mapping model, thus realizing a higher encoding efficiency and encoding quality.

A method of controlling residual coding for decoding or encoding of a video sequence, is performed by at least one processor and includes determining whether a small transform size of a primary transform is to be used for the residual coding of a coded block of the video sequence. The method further includes based on the small transform size of the primary transform being determined to be used, identifying, as the primary transform, a first transform set including discrete sine transform (DST)-4 and discrete cosine transform (DCT)-4, based on the small transform size of the primary transform being determined to not be used, identifying, as the primary transform, a second transform set including DST-7 and DCT-8, and performing the residual coding of the coded block, using the identified primary transform.

The invention discloses a method for built-in steganography of an H.265 video. Information embedding is carried out for the DST (Discrete Sine Transform) coefficient of a 4*4 luminance residual block. First, two directions of distortion drift are determined according to the intra-frame prediction mode of an H.265 video. Then, a triple of a corresponding format is selected for information embedding according to the specific direction of distortion drift. As the triple used has a coefficient compensation effect, 4*4 luminance block pixels causing distortion drift do not change during inverse transformation of the embedded DST coefficient of the residual block, and the purpose of distortion drift control during built-in steganography is achieved. Experimental results show that the method for built-in steganography of an H.265 video provided by the invention can effectively control intra-frame distortion drift, and has good visual imperceptibility and a good visual effect.