Results 171 to 180 of about 113,115 (217)
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Spatial filtering with volume gratings
Applied Optics, 1985The angular selectivity property of a volume grating is used to form spatial frequency filter. A grating having a controlled depth modulation acts as a filter with a line spread function that is equal to the modulation variation in depth, properly scaled.
D, Peri, D, Ritter
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A SPATIAL FILTER FOR SIMILARITY RETRIEVAL
International Journal of Pattern Recognition and Artificial Intelligence, 1996Recently, Yang and Lee13 proposed a powerful data structure, the 2D B-string, to express the spatial knowledge embedded in iconic images. The data structure can be used to describe images with partly- or completely- overlapping objects without the need for partitioning the objects.
Chin-Chen Chang 0001, Ji-Han Jiang
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Spatial filters for replicating images
Optics Letters, 1986The conditions for self-imaging, longitudinal periodicity are relaxed to demand image replication only along the optical axis. Lateral periodicity in the square of the radius, in the spatial-frequency domain, is necessary and sufficient for image replication along the optical axis.
J, Ojeda-Castañeda +2 more
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Smooth Spatial Filter for Common Spatial Patterns
2013Common Spatial Patterns CSPs is a popular feature extraction algorithm for Brain-Computer Interface BCI. However, the standard CSP spatial filters completely ignore the spatial information of EEG electrodes. To solve this problem, two smooth Regularized CSP RCSP algorithms are proposed in this paper, which are Spatially RCSP with a Gaussian Prior ...
Xuan Li 0001, Haixian Wang
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Spatial Filtering for Robust Myoelectric Control
IEEE Transactions on Biomedical Engineering, 2012Pattern recognition techniques have been applied to extract information from electromyographic (EMG) signals that can be used to control electrical powered hand prostheses. In this paper, optimized spatial filters that enhance separation properties of EMG signals are investigated.
Janne Mathias Hahne +2 more
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Optical Spatial Filtering of Radiographic Images with Binary Filters
Radiology, 1974An optical spatial filtering technique was used to remove grid lines by eliminating the transmission of the corresponding Fourier spectrum in the Fourier transform plane. Studies of the effect of band-pass filtering on cerebral angiograms showed that a recognizable image of the blood vessels is produced even when the filter is placed in a spatial ...
D J, Goodenough, K, Doi, K, Rossmann
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Infrared Physics, 1964
Abstract Design and synthesis of one-dimensional low-pass and band-pass spatial filters are developed by approximating the space domain transient response of the filters with rectangular detectors. The transforms of the approximating functions are derived analytically.
K. Seyrafi, G.A. Davison
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Abstract Design and synthesis of one-dimensional low-pass and band-pass spatial filters are developed by approximating the space domain transient response of the filters with rectangular detectors. The transforms of the approximating functions are derived analytically.
K. Seyrafi, G.A. Davison
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