A method and apparatus for the exploration of hydrocarbons comprising the steps of: obtaining a set of seismic signal traces distributed over a predetermined three-dimensional volume of the earth; dividing the three-dimensional volume into a plurality of analysis cells having portions of at least two seismic traces located therein; computing outer products of the seismic traces within each cell; forming the covariance matrix for each cell from these outer products; computing the dominant eigenvalue and the sum of the eigenvalues of the covariance matrix of each cell and computing a seismic attribute from the ratio of the dominant eigenvalue to the sum of the eigenvalues of the covariance matrix of each cell; and forming map of the seismic attributes of selected groups of cells.

Method and apparatus for seismic signal processing and exploration

An inverse discrete cosine transform ("IDCT") implementation specifically for the decompression of JPEG, MPEG and Px64 encoded image and video data uses a preprocessing step embedded in a Huffman decoding process to classify data blocks prior to computing the IDCT. The use of data block classification, along with the use of pruned IDCTs appropriate for the specific block class, reduces the total number of multiply and addition operations necessary to decompress an encoded data block, and thereby allows faster data decompression. Synthesis of coefficients suitable for multiplication allows efficient implementation of the novel decompression technique in typical microprocessor architectures, including RISC processor architectures.

Method and apparatus for fast digital signal decoding.

An apparatus and method for determining wave characteristics from wave phenomena. The apparatus and method employ eigenvectors to yield a variety of wave characteristics from wave phenomena data.

Method and apparatus for determining wave characteristics from wave phenomena

The preferred embodiment includes a method and system for processing ultrasound data during or after compression. Various compression algorithms, such as JPEG compression, are used to transfer ultrasound data. The ultrasound data may include image (i.e. video data) or data obtained prior to scan conversion, such as detected acoustic line data or data complex in form. Compression algorithms typically include a plurality of steps to transform and quantize the ultrasound data. Various processes in addition to compression may be performed as part of one or more of the compression steps. Furthermore, various ultrasound system processes typically performed on uncompressed ultrasound data may be performed using compressed or partially compressed ultrasound data. Operation on compressed or partially compressed data may more efficiently provide processed data for generation of an image. Fewer operations are required by one or more processors when operating on compressed or partially compressed data than for uncompressed or non-compressed data. In one embodiment, partially compressed data may be input into a look-up table for contrast enhancement. In another embodiment, partially compressed data is high passed filtered.

Medical diagnostic ultrasound system and method for transform ultrasound processing

A method for imparting to a general purpose (CISC), or reduced instruction set (RISC), type of central processing unit (CPU; microprocessor) the characteristics and performance of an integer arithmetic digital signal processor (DSP) which executes instructions acting upon multiple ("S") data elements in parallel. The method is applicable to all finite mathematical computations wherein product and sum terms (for example) will never overflow "1/S" fraction of total word width. "S" need not be a multiple of two, but the method is most useful when it is, such as in algorithms containing "butterfly" type computations. It may be used to advantage in the implementation of all discrete orthogonal transforms, and may be generalized to any size CPU word (e.g.: 16-bit, 32-bit, 64-bit, etc.) subject only to limits imposed by the range of vector spaces being handled. Specific applications include single and multiple dimensional Discrete Cosine Transform for image compression, and real and complex Fast Fourier Transform for coding of audio and similar time sequence data.

Fast inverse discrete transform using subwords for decompression of information

A signal processing apparatus and method for iteratively determining the inverse Arithmetic Fourier Transform (AFT) of an input signal by converting the input signal, which represents Fourier coefficients of a function that varies in relation to time, space, or other independent variable, into a set of output signals representing the values of a Fourier series associated with the input signal. The signal processing apparatus and method utilize a process in which a data set of samples is used to iteratively compute a set of frequency samples, wherein each computational iteration utilizes error information which is calculated between the initial data and data synthesized using the AFT. The iterative computations converge and provide AFT values at the Farey-fraction arguments which are consistent with values given by a zero-padded Discrete Fourier Transform (DFT), thus obtaining dense frequency domain samples without interpolation or zero-padding.

Donald W. Tufts

Papers

Signal processing apparatus and method for iteratively determining Arithmetic Fourier Transform