Abstract: A method for automatic, stable and robust object extraction of moving objects in color video frames, achieved without any prior knowledge of the video content. For high rate video, the method includes providing at least a first and a second high frame rate video frames, performing a reciprocal illumination correction of the first and second video frames to yield respective first and second smoothed frames, performing a change detection operation between the first and second smoothed frames to obtain a difference image, and performing a local adaptive thresholding operation on the difference image to generate a binary image containing extracted objects, the local thresholding operation using a weight test to determine a boundary of each of the extracted objects. For an extracted object with a fragmented boundary, the method further comprises re-unifying the boundary.

Abstract: A method of generating a parser of a source code file that references a syntactic dictionary, a method of compressing the file, and apparatuses that use the methods. The syntactic dictionary is converted into a corresponding plurality of expressions, of a context-free grammar, that are a grammar of the source code. The parser is constructed from the expressions. The source code is compressed using the parser. Preferably, the grammar of the source code file is a D-grammar and the expressions are regular expressions. Preferably, the parser is a deterministic pushdown transducer. An important case of the present invention is that in which the source code is XML code and the syntactic dictionary is the document type declaration of the XML code. Apparatuses that use a parser of the present invention include compressors, decompressors, validators, converters, editors, network devices and end-user/hand-held devices.

Abstract: A method for illumination-independent change detection in a pair of original registered gray images based on blob extraction. Blobs are extracted from the two original images and their negatives, using an enhanced blob extraction algorithm based on connectivity analysis along gray-levels. Blobs extracted from the first original and negative images are compared with blobs extracted from the second original and negative images to determine whether each blob has a corresponding blob, i.e. whether it is a matched or unmatched blob. All unmatched blobs are tested for significance as “blobs of change” using a fitness measure based on either a ratio of saliency gradients, or a product of this ratio and a gradient distribution measure.

Abstract: Apparatus and method for performing fast compression and decompression of seismic data. An adaptive transform (124) with selectable mathematical basis is applied to an initial data set to obtain a set of transformed coefficients, the transform factorizing an effective symmetric or non-symmetric biorthogonal filter of size (u, v) into a number m of elementary (3, 1) biorthogonal filters which are applied to the data set in selected directions without requiring transposition of the data set. The coefficients are encoded (126) using non-uniform scalar quantization and run-length coding followed by adaptive coding of resulting threshold coefficients. The transform and encoding steps are repeated (128) using a new mathematical basis for each iteration to obtain a compressed data set at a desired compression rate. Exact compression ratios can be obtained (158), allowing evaluation of the data in the compressed domain as well as transparent, on-the-fly decompression at computer network data transfer rates.

Abstract: A method for fast motion estimation determines the relative motion between a first and a second image by using either a bi-directional gradient method (BDGM) or a symmetric gradient method (SGM) approach. The global motion, defined by a plurality of parameters in which each parameter has an interval, is estimated by providing an initial estimate of two translation parameters each having an interval of values, dividing each interval into two non-equal (BDGM) or equal (SGM) sub-intervals, and using an iterative process starting with the initial estimate of the two equal sub-intervals. The iterative process calculates the optimal value (BDGM) or a center value (SGM) of the value interval of each parameter and yields a final parameters vector defining the global motion. The bi-directional and the symmetric gradient methods provide faster convergence and smaller linearization error, or convergence in cases where regular gradient methods do not converge.

Abstract: A method for automatic, stable and robust object extraction of moving objects in color video frames, achieved without any prior knowledge of the video content. For high rate video, the method includes providing at least a first and a second high frame rate video frames, performing a reciprocal illumination correction of the first and second video frames to yield respective first and second smoothed frames, performing a change detection operation between the first and second smoothed frames to obtain a difference image, and performing a local adaptive thresholding operation on the difference image to generate a binary image containing extracted objects, the local thresholding operation using a weight test to determine a boundary of each of the extracted objects. For an extracted object with a fragmented boundary, the method further comprises re-unifying the boundary.