Autotek autocad raster design 2010 用户手册

Raster Design uses the following Laplace edge enhancements filters:

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#1 uses the target pixel and its horizontal and vertical neighbors. Diagonally
adjacent pixels are ignored.

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#2 uses a uniform kernel with a high weighting on the target pixel.

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#3 uses a uniform kernel with the highest weighting on the target pixel.

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#4 weighs adjacent horizontal and vertical pixels more heavily than
diagonally adjacent pixels.

You can use these filters in any one of the eight compass directions. Using
these directional filters results in a black background with white outlines of
the objects in the original image.

Each filter enhances the edges composed of black-to-white transitions in a
specific direction, making these edges white. Raster Design uses the following
gradient directional edge enhancements filters:

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North

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Northeast

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East

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Southeast

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South

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Southwest

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West

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Northwest

You can use these filters to search for features in images that are obscured by

 (page 393). These filters use a directional 3x5 or 5x3 pixel kernel.

Raster Design uses the following matched filter edge enhancements filters:

Horizontal searches for horizontal lines in a noisy image.

Convolving an Image | 111