classgdaldataset.html

gdal库的学习文档

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          <td class="memname">int GDALDataset::GetShared           </td>
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Returns shared flag.<p>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>TRUE if the <a class="el" href="classGDALDataset.html">GDALDataset</a> is available for sharing, or FALSE if not. </dd></dl>

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          <td class="memname">void GDALDataset::MarkAsShared           </td>
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Mark this dataset as available for sharing. 
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<a class="anchor" name="7943fb46c770e2ed35357e7883bb1814"></a><!-- doxytag: member="GDALDataset::GetOpenDatasets" ref="7943fb46c770e2ed35357e7883bb1814" args="(int *pnDatasetCount)" -->
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          <td class="memname"><a class="el" href="classGDALDataset.html">GDALDataset</a> ** GDALDataset::GetOpenDatasets           </td>
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Fetch all open GDAL dataset handles.<p>
This method is the same as the C function <a class="el" href="gdal_8h.html#e3e17b1b12d55da2815a951900dc412e">GDALGetOpenDatasets()</a>.<p>
NOTE: This method is not thread safe. The returned list may changed at any time.<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
  <table border="0" cellspacing="2" cellpadding="0">
    <tr><td valign="top"></td><td valign="top"><em>pnCount</em>&nbsp;</td><td>integer into which to place the count of dataset pointers being returned.</td></tr>
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<dl class="return" compact><dt><b>Returns:</b></dt><dd>a pointer to an array of dataset handles. </dd></dl>

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<a class="anchor" name="2aa6f88b3bbc840a5696236af11dde15"></a><!-- doxytag: member="GDALDataset::BuildOverviews" ref="2aa6f88b3bbc840a5696236af11dde15" args="(const char *, int, int *, int, int *, GDALProgressFunc, void *)" -->
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          <td class="memname">CPLErr GDALDataset::BuildOverviews           </td>
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Build raster overview(s)<p>
If the operation is unsupported for the indicated dataset, then CE_Failure is returned, and <a class="el" href="cpl__error_8h.html#198afe56aced1d73226880aa90d39b99">CPLGetLastErrorNo()</a> will return CPLE_NotSupported.<p>
This method is the same as the C function <a class="el" href="gdal_8h.html#767f4456a6249594ee18ea53f68b7e80">GDALBuildOverviews()</a>.<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
  <table border="0" cellspacing="2" cellpadding="0">
    <tr><td valign="top"></td><td valign="top"><em>pszResampling</em>&nbsp;</td><td>one of "NEAREST", "AVERAGE" or "MODE" controlling the downsampling method applied. </td></tr>
    <tr><td valign="top"></td><td valign="top"><em>nOverviews</em>&nbsp;</td><td>number of overviews to build. </td></tr>
    <tr><td valign="top"></td><td valign="top"><em>panOverviewList</em>&nbsp;</td><td>the list of overview decimation factors to build. </td></tr>
    <tr><td valign="top"></td><td valign="top"><em>nBand</em>&nbsp;</td><td>number of bands to build overviews for in panBandList. Build for all bands if this is 0. </td></tr>
    <tr><td valign="top"></td><td valign="top"><em>panBandList</em>&nbsp;</td><td>list of band numbers. </td></tr>
    <tr><td valign="top"></td><td valign="top"><em>pfnProgress</em>&nbsp;</td><td>a function to call to report progress, or NULL. </td></tr>
    <tr><td valign="top"></td><td valign="top"><em>pProgressData</em>&nbsp;</td><td>application data to pass to the progress function.</td></tr>
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<dl class="return" compact><dt><b>Returns:</b></dt><dd>CE_None on success or CE_Failure if the operation doesn't work.</dd></dl>
For example, to build overview level 2, 4 and 8 on all bands the following call could be made: <pre>
   int       anOverviewList[3] = { 2, 4, 8 };</pre><p>
<pre>   poDataset-&gt;BuildOverviews( "NEAREST", 3, anOverviewList, 0, NULL, 
                              GDALDummyProgress, NULL );
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<hr><h2>Friends And Related Function Documentation</h2>
<a class="anchor" name="6764788806a1785c97036d1dba064497"></a><!-- doxytag: member="GDALDataset::GDALOpen" ref="6764788806a1785c97036d1dba064497" args="(const char *, GDALAccess)" -->
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          <td class="memname">GDALDatasetH GDALOpen           </td>
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<p>
Open a raster file as a <a class="el" href="classGDALDataset.html">GDALDataset</a>.<p>
This function will try to open the passed file, or virtual dataset name by invoking the Open method of each registered <a class="el" href="classGDALDriver.html">GDALDriver</a> in turn. The first successful open will result in a returned dataset. If all drivers fail then NULL is returned.<p>
<dl class="see" compact><dt><b>See also:</b></dt><dd><a class="el" href="classGDALDataset.html#347b1025e090c5238196b658463addd3">GDALOpenShared()</a></dd></dl>
<dl compact><dt><b>Parameters:</b></dt><dd>
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    <tr><td valign="top"></td><td valign="top"><em>pszFilename</em>&nbsp;</td><td>the name of the file to access. In the case of exotic drivers this may not refer to a physical file, but instead contain information for the driver on how to access a dataset.</td></tr>
    <tr><td valign="top"></td><td valign="top"><em>eAccess</em>&nbsp;</td><td>the desired access, either GA_Update or GA_ReadOnly. Many drivers support only read only access.</td></tr>
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<dl class="return" compact><dt><b>Returns:</b></dt><dd>A GDALDatasetH handle or NULL on failure. For C++ applications this handle can be cast to a <a class="el" href="classGDALDataset.html">GDALDataset</a> *. </dd></dl>

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<a class="anchor" name="347b1025e090c5238196b658463addd3"></a><!-- doxytag: member="GDALDataset::GDALOpenShared" ref="347b1025e090c5238196b658463addd3" args="(const char *, GDALAccess)" -->
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Open a raster file as a <a class="el" href="classGDALDataset.html">GDALDataset</a>.<p>
This function works the same as <a class="el" href="classGDALDataset.html#6764788806a1785c97036d1dba064497">GDALOpen()</a>, but allows the sharing of <a class="el" href="classGDALDataset.html">GDALDataset</a> handles for a dataset with other callers to <a class="el" href="classGDALDataset.html#347b1025e090c5238196b658463addd3">GDALOpenShared()</a>.<p>
In particular, <a class="el" href="clas