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<h2>DESCRIPTION</h2>
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<h2>DESCRIPTION</h2>
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-<em>i.zc</em> is an image processing program used for edge
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+<em>i.zc</em> is an image processing module used for edge
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detection. The raster map produced shows the location of
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detection. The raster map produced shows the location of
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"boundaries" on the input map. Boundaries tend to be found
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"boundaries" on the input map. Boundaries tend to be found
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in regions of changing cell values and tend to run
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in regions of changing cell values and tend to run
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@@ -8,63 +8,6 @@ perpendicular to the direction of the slope. The algorithm
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used for edge detection is one of the "zero-crossing"
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used for edge detection is one of the "zero-crossing"
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algorithms and is discussed briefly below.
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algorithms and is discussed briefly below.
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-<h2>OPTIONS</h2>
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-
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-<h3>Parameters:</h3>
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-
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-<dl>
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-
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-<dt><b>input_map=</b><em>name</em>
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-
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-<dd>Name of input raster map layer.
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-
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-<dt><b>zc_map=</b><em>name</em>
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-
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-<dd>Name of raster map layer to be used for zero-crossing values.
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-
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-<dt><b>width=</b><em>value</em>
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-
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-<dd>This parameter determines the x-y extent of the
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-Gaussian filter. The default value is 9; higher and lower
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-values can be tested by the user. Increasing the width
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-will result in finding "edges" representing more gradual
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-changes in cell values.
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-
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-<br>
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-
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-Default: 9
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-
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-<dt><b>threshold=</b><em>value</em>
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-
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-<dd>This parameter determines the "sensitivity" of the
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-Gaussian filter. The default value is 10; higher and
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-lower values can be tested by the user. Increasing the
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-threshold value will result in fewer edges being found.
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-
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-<br>
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-
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-Default: 10
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-
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-<dt><b>orientations=</b><em>value</em>
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-
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-<dd>This value is the number of azimuth directions the
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-cells on the output raster map layer are categorized into
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-(similar to the aspect raster map layer produced by the
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-
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-<em><a href="r.slope.aspect.html">r.slope.aspect</a></em>
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-
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-program). For example, a value of 16 would result in
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-detected edges being categorized into one of 16 bins
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-depending on the direction of the edge at that point.
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-
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-<br>
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-
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-Default: 1
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-
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-</dl>
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-
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-The current region definition and mask settings are respected
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-when reading the input map.
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<h2>NOTES</h2>
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<h2>NOTES</h2>
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@@ -83,13 +26,40 @@ is marked as an edge and an orientation is assigned to it.
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The resulting raster map layer is output.
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The resulting raster map layer is output.
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</ol>
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</ol>
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+The <b>width=</b> parameter determines the x-y extent of the
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+Gaussian filter. The default value is <b>9</b>; higher and lower
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+values can be tested by the user. Increasing the width
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+will result in finding "edges" representing more gradual
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+changes in cell values.
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+
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+<p>
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+The <b>threshold=</b> parameter determines the "sensitivity" of the
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+Gaussian filter. The default value is <b>10</b>; higher and
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+lower values can be tested by the user. Increasing the
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+threshold value will result in fewer edges being found.
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+
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+<p>
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+The <b>orientations=</b> value is the number of azimuth directions the
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+cells on the output raster map layer are categorized into
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+(similar to the aspect raster map layer produced by
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+<em><a href="r.slope.aspect.html">r.slope.aspect</a></em>.
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+For example, a value of <b>16</b> would result in
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+detected edges being categorized into one of 16 bins
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+depending on the direction of the edge at that point.
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+
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+<p>
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+The current region definition and mask settings are respected
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+when reading the input map.
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+
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<h2>SEE ALSO</h2>
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<h2>SEE ALSO</h2>
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-<em><a href="i.fft.html">i.fft</a></em>,
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-<em><a href="i.ifft.html">i.ifft</a></em>,
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-<em><a href="r.mapcalc.html">r.mapcalc</a></em>,
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-<em><a href="r.mfilter.html">r.mfilter</a></em>,
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-<em><a href="r.slope.aspect.html">r.slope.aspect</a></em>
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+<em>
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+<a href="i.fft.html">i.fft</a>,
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+<a href="i.ifft.html">i.ifft</a>,
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+<a href="r.mapcalc.html">r.mapcalc</a>,
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+<a href="r.mfilter.html">r.mfilter</a>,
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+<a href="r.slope.aspect.html">r.slope.aspect</a>
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+</em>
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<h2>AUTHOR</h2>
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<h2>AUTHOR</h2>
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