System for shape recognition
AssigneeSchlumberger Systems & Services, Inc.
InventorH. Keith Nishihara
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Abstract
A system for shape recognition includes a spatial convolution filter which has an approximately band pass response. The filter is applied to a camera image and the sign of the filter's output is used to produce a second binary image. At sufficiently coarse (low center spatial frequency) scales, this image tends to change isolated shapes into single blob-shaped regions. The same convolution operator is then reapplied to this binary signal blob image and peaks in the output of the second convolution are used as the primitive elements for building a shape description. By processing the image with operators of two different scales the peaks shift position. The location of peaks from the coarse scale operator together with vectors to the fine scale peaks provide a description of the shape for a look-up table or other system.
Claims5
A machine method of processing an image containing pixels comprising:
- applying a first Laplacian of Gaussian convolution to the image to produce a first filtered image;
- extracting the sign of each pixel in the first filtered image to provide a second filtered image;
- applying a second Laplacian of Gaussian convolution to the second filtered image to provide a third filtered image;
- and
- detecting a first set of peaks in the third filtered image, where said peaks are used to establish a shape description of original image.
Dependencies are inferred from the claim text.