Raster.md

+This plugin supports reading tiff and geotiff files.
+
+Tiled or Stripped tiff files are required and when rasters are small < 200-300 MB this driver is faster that the [[GDAL]] plugin.
+
+If files are larger it is recommended to build GDAL overviews (with gdaladdo command) and instead read with the [[GDAL]] plugin.
+
+**Note: overviews support is available only in Mapnik >= 0.7.0**
+
+A drawback(or advantage!) of this plugin is that it requires manually setting the file bounds.
+
+ * hint: create a GDAL datasource from your tiff in python, call the envelope() method to get the bounds, and use those.
+
+For other plugins see: [[PluginArchitecture]]
+
+# Installation
+
+To check if the raster plugin built and was installed correctly you can do:
+
+
+```python
+>>> from mapnik import DatasourceCache as c
+>>> 'raster' in c.plugin_names()
+True
+```
+
+# Parameters
+
+
+<table>
+<tr>
+<td> <strong>parameter</strong> </td>
+<td> <strong>value</strong>  </td>
+<td> <strong>description</strong> </td>
+<td> <strong>default</strong> </td>
+</tr>
+<tr>
+<td> file            </td>
+<td> string       </td>
+<td> geotiff file path  </td>
+</tr>
+<tr>
+<td> base            </td>
+<td> string       </td>
+<td> optional base path where to search for the tiff raster file  </td>
+</tr>
+<tr>
+<td> lox             </td>
+<td> double       </td>
+<td> lower x corner of the image in map coordinates </td>
+</tr>
+<tr>
+<td> loy             </td>
+<td> double       </td>
+<td> lower y corner of the image in map coordinates </td>
+</tr>
+<tr>
+<td> hix             </td>
+<td> double       </td>
+<td> upper x corner of the image in map coordinates </td>
+</tr>
+<tr>
+<td> hiy             </td>
+<td> double       </td>
+<td> upper y corner of the image in map coordinates </td>
+</tr>
+<tr>
+<td> extent          </td>
+<td> string       </td>
+<td> extent of the image in map coordinates, comma or space separated (at least <lox> <loy> <hix> <hiy> or <extent> should be passed) </td>
+</tr>
+<tr>
+<td> format          </td>
+<td> string       </td>
+<td> image format to use, currently only tiff is supported </td>
+<td> tiff </td>
+</tr>
+</table>
+
+
+# Styling
+
+To style a layer use the [[RasterSymbolizer]]
+
+# Usage
+
+## Python
+
+```xml
+<!-- NOTE: must be in the same SRS as your map-->
+<Layer name="Raster">
+    <StyleName>raster</StyleName>
+    <Datasource>
+        <Parameter name="type">raster</Parameter>
+        <Parameter name="file">/path/to/my/raster/file.tiff</Parameter>
+        <Parameter name="lox">min_x</Parameter>
+        <Parameter name="loy">min_y</Parameter>
+        <Parameter name="hix">max_x</Parameter>
+        <Parameter name="hiy">max_y</Parameter>
+    </Datasource>
+</Layer>
+
+from mapnik import Raster, Layer
+raster = Raster(base='/home/mapnik/data',file='/path/to/my/raster/file.tiff',lox=minx,loy=min_y,hix=max_x,hiy=max_y)
+lyr = Layer('Tiff Layer')
+lyr.datasource = raster
+
+```
+
+## C++
+
+Plugin datasource initialization example code can be found on [[PluginArchitecture]].
+
+A Raster datasource may be created as follows:
+
+
+```cpp
+{
+    parameters p;
+    p["type"]="raster";
+    p["file"]="/path/to/my/raster/file.tiff";
+    p["lox"]=min_x;
+    p["loy"]=min_y;
+    p["hix"]=max_x;
+    p["hiy"]=max_y;
+
+    set_datasource(datasource_cache::instance()->create(p));
+
+    layer lyr("Raster");
+    lyr.add_style("raster");
+    m.add_layer(lyr);
+}
+```
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