support nodata for paletted images and allow user to set nodata on-the-fly - closes #1160 and #1161 - refs #688 and refs #730 and refs #50 and refs #1018

CHANGELOG.md

@@ -9,6 +9,10 @@ For a complete change history, see the SVN log.
 
 ## Mapnik 2.1.0
 
+- GDAL: allow setting nodata value on the fly (will override value if nodata is set in data) (#1161)
+ 
+- GDAL: respect nodata for paletted/colormapped images (#1160)
+
 - PostGIS: the primary key, for tables containing one, is now auto-detected allowing for globally unique feature id values (#804)
 
 - Fix Markers rendering so that ellipse height/width units are pixels (previously were unintentially radii)

plugins/input/gdal/gdal_datasource.cpp

@@ -78,7 +78,8 @@ inline GDALDataset* gdal_datasource::open_dataset() const
 gdal_datasource::gdal_datasource(parameters const& params, bool bind)
     : datasource(params),
       desc_(*params.get<std::string>("type"), "utf-8"),
-      filter_factor_(*params_.get<double>("filter_factor", 0.0))
+      filter_factor_(*params_.get<double>("filter_factor", 0.0)),
+      nodata_value_(params_.get<double>("nodata"))
 {
 #ifdef MAPNIK_DEBUG
     std::clog << "GDAL Plugin: Initializing..." << std::endl;
@@ -242,7 +243,8 @@ featureset_ptr gdal_datasource::features(query const& q) const
                                               nbands_,
                                               dx_,
                                               dy_,
-                                              filter_factor_));
+                                              filter_factor_,
+                                              nodata_value_));
 }
 
 featureset_ptr gdal_datasource::features_at_point(coord2d const& pt) const
@@ -261,5 +263,6 @@ featureset_ptr gdal_datasource::features_at_point(coord2d const& pt) const
                                               nbands_,
                                               dx_,
                                               dy_,
-                                              filter_factor_));
+                                              filter_factor_,
+                                              nodata_value_));
 }

plugins/input/gdal/gdal_datasource.hpp

@@ -57,6 +57,7 @@ private:
     mutable int nbands_;
     mutable bool shared_dataset_;
     double filter_factor_;
+    boost::optional<double> nodata_value_;
     inline GDALDataset* open_dataset() const;
 };
 

plugins/input/gdal/gdal_featureset.cpp

@@ -53,7 +53,8 @@ gdal_featureset::gdal_featureset(GDALDataset& dataset,
                                  int nbands,
                                  double dx,
                                  double dy,
-                                 double filter_factor)
+                                 double filter_factor,
+                                 boost::optional<double> const& nodata)
     : dataset_(dataset),
       ctx_(boost::make_shared<mapnik::context_type>()),
       band_(band),
@@ -65,6 +66,7 @@ gdal_featureset::gdal_featureset(GDALDataset& dataset,
       dy_(dy),
       nbands_(nbands),
       filter_factor_(filter_factor),
+      nodata_value_(nodata),
       first_(true)
 {
     ctx_->push("value");
@@ -241,8 +243,17 @@ feature_ptr gdal_featureset::get_feature(mapnik::query const& q)
 
                 float* imageData = (float*)image.getBytes();
                 GDALRasterBand * band = dataset_.GetRasterBand(band_);
-                int hasNoData;
+                int hasNoData(0);
-                double nodata = band->GetNoDataValue(&hasNoData);
+                double nodata(0);
+                if (nodata_value_)
+                {
+                    hasNoData = 1;
+                    nodata = *nodata_value_;
+                }
+                else
+                {
+                    nodata = band->GetNoDataValue(&hasNoData);
+                }
                 band->RasterIO(GF_Read, x_off, y_off, width, height,
                                imageData, image.width(), image.height(),
                                GDT_Float32, 0, 0);
@@ -340,8 +351,21 @@ feature_ptr gdal_featureset::get_feature(mapnik::query const& q)
 #ifdef MAPNIK_DEBUG
                     std::clog << "GDAL Plugin: processing rgb bands..." << std::endl;
 #endif
-                    int hasNoData;
+                    int hasNoData(0);
-                    float nodata = red->GetNoDataValue(&hasNoData);
+                    double nodata(0);
+                    if (nodata_value_)
+                    {
+                        hasNoData = 1;
+                        nodata = *nodata_value_;
+                    }
+                    else
+                    {
+                        nodata = red->GetNoDataValue(&hasNoData);
+                    }
+                    if (hasNoData)
+                    {
+                        feature->put("NODATA",nodata);
+                    }
                     GDALColorTable *color_table = red->GetColorTable();
 
                     if (! alpha && hasNoData && ! color_table)
@@ -380,12 +404,25 @@ feature_ptr gdal_featureset::get_feature(mapnik::query const& q)
 #ifdef MAPNIK_DEBUG
                     std::clog << "GDAL Plugin: processing gray band..." << std::endl;
 #endif
-                    int hasNoData;
+                    int hasNoData(0);
-                    float nodata = grey->GetNoDataValue(&hasNoData);
+                    double nodata(0);
+                    if (nodata_value_)
+                    {
+                        hasNoData = 1;
+                        nodata = *nodata_value_;
+                    }
+                    else
+                    {
+                        nodata = grey->GetNoDataValue(&hasNoData);
+                    }
                     GDALColorTable* color_table = grey->GetColorTable();
 
                     if (hasNoData && ! color_table)
                     {
+                        if (hasNoData)
+                        {
+                            feature->put("NODATA",nodata);
+                        }
 #ifdef MAPNIK_DEBUG
                         std::clog << "\tno data value for layer: " << nodata << std::endl;
 #endif
@@ -422,23 +459,41 @@ feature_ptr gdal_featureset::get_feature(mapnik::query const& q)
 #ifdef MAPNIK_DEBUG
                         std::clog << "GDAL Plugin: Loading colour table..." << std::endl;
 #endif
+                        unsigned nodata_value = static_cast<unsigned>(nodata);
+                        if (hasNoData)
+                        {
+                            feature->put("NODATA",static_cast<int>(nodata_value));
+                        }
                         for (unsigned y = 0; y < image.height(); ++y)
                         {
                             unsigned int* row = image.getRow(y);
                             for (unsigned x = 0; x < image.width(); ++x)
                             {
                                 unsigned value = row[x] & 0xff;
+                                if (hasNoData && (value == nodata_value))
+                                {
+                                    // make no data fully alpha
+                                    row[x] = 0;
+                                }
+                                else
+                                {
                                     const GDALColorEntry *ce = color_table->GetColorEntry(value);
-                                if (ce )
+                                    if (ce)
                                     {
                                         // TODO - big endian support
                                         row[x] = (ce->c4 << 24)| (ce->c3 << 16) |  (ce->c2 << 8) | (ce->c1) ;
                                     }
+                                    else
+                                    {
+                                        // make lacking color entry fully alpha
+                                        // note - gdal_translate makes black
+                                        row[x] = 0;
+                                    }
+                                }
                             }
                         }
                     }
                 }
-
                 if (alpha)
                 {
 #ifdef MAPNIK_DEBUG

plugins/input/gdal/gdal_featureset.hpp

@@ -29,6 +29,7 @@
 
 // boost
 #include <boost/variant.hpp>
+#include <boost/optional.hpp>
 
 class GDALDataset;
 class GDALRasterBand;
@@ -47,7 +48,8 @@ public:
                     int nbands,
                     double dx,
                     double dy,
-                    double filter_factor);
+                    double filter_factor,
+                    boost::optional<double> const& nodata);
     virtual ~gdal_featureset();
     mapnik::feature_ptr next();
 private:
@@ -67,6 +69,7 @@ private:
     double dy_;
     int nbands_;
     double filter_factor_;
+    boost::optional<double> nodata_value_;
     bool first_;
 };
 

tests/data/good_maps/tiff_colortable.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Map srs="+init=epsg:32630" background-color="rgb(255,255,255)">
+    <Style name="2011_5km_vrt_nodata_style">
+        <Rule>
+            <RasterSymbolizer/>
+        </Rule>
+    </Style>
+    <Layer name="2011_5km_vrt_nodata" srs="+init=epsg:32630">
+        <StyleName>2011_5km_vrt_nodata_style</StyleName>
+        <Datasource>
+            <Parameter name="file">../raster/dataraster.tif</Parameter>
+            <Parameter name="nodata">20</Parameter>
+            <Parameter name="type">gdal</Parameter>
+        </Datasource>
+    </Layer>
+</Map>

tests/data/good_maps/vrt_colortable.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Map srs="+init=epsg:32630" background-color="rgb(255,255,255)">
+    <Style name="2011_5km_vrt_nodata_style">
+        <Rule>
+            <RasterSymbolizer/>
+        </Rule>
+    </Style>
+    <Layer name="2011_5km_vrt_nodata" srs="+init=epsg:32630">
+        <StyleName>2011_5km_vrt_nodata_style</StyleName>
+        <Datasource>
+            <Parameter name="file">../raster/dataraster.vrt</Parameter>
+            <Parameter name="type">gdal</Parameter>
+        </Datasource>
+    </Layer>
+</Map>

tests/data/raster/dataraster.vrt

@@ -0,0 +1,45 @@
+<VRTDataset rasterXSize="2283" rasterYSize="1913">
+  <SRS>PROJCS[&quot;WGS 84 / UTM zone 30N&quot;,GEOGCS[&quot;WGS 84&quot;,DATUM[&quot;WGS_1984&quot;,SPHEROID[&quot;WGS 84&quot;,6378137,298.257223563,AUTHORITY[&quot;EPSG&quot;,&quot;7030&quot;]],AUTHORITY[&quot;EPSG&quot;,&quot;6326&quot;]],PRIMEM[&quot;Greenwich&quot;,0],UNIT[&quot;degree&quot;,0.0174532925199433],AUTHORITY[&quot;EPSG&quot;,&quot;4326&quot;]],PROJECTION[&quot;Transverse_Mercator&quot;],PARAMETER[&quot;latitude_of_origin&quot;,0],PARAMETER[&quot;central_meridian&quot;,-3],PARAMETER[&quot;scale_factor&quot;,0.9996],PARAMETER[&quot;false_easting&quot;,500000],PARAMETER[&quot;false_northing&quot;,0],UNIT[&quot;metre&quot;,1,AUTHORITY[&quot;EPSG&quot;,&quot;9001&quot;]],AUTHORITY[&quot;EPSG&quot;,&quot;32630&quot;]]</SRS>
+  <GeoTransform> -1.4637000000000000e+04,  5.0000000000000000e+02,  0.0000000000000000e+00,  4.8596780000000000e+06,  0.0000000000000000e+00, -5.0000000000000000e+02</GeoTransform>
+  <VRTRasterBand dataType="Int16" band="1">
+    <NoDataValue>-9.99000000000000E+02</NoDataValue>
+    <HideNoDataValue>0</HideNoDataValue>
+    <ColorInterp>Palette</ColorInterp>  
+    <ColorTable>
+        <Entry c1="0" c2="0" c3="0" c4="0"/>
+        <Entry c1="0" c2="0" c3="255"/>
+        <Entry c1="0" c2="255" c3="0"/>
+        <Entry c1="255" c2="0" c3="0"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="128" c2="128" c3="128"/>
+        <Entry c1="0" c2="0" c3="255"/>
+        <Entry c1="0" c2="255" c3="0"/>
+        <Entry c1="255" c2="0" c3="0"/>
+    </ColorTable>
+    <ComplexSource>
+      <SourceFilename relativeToVRT="1">dataraster.tif</SourceFilename>
+      <SourceBand>1</SourceBand>
+      <SourceProperties RasterXSize="2283" RasterYSize="1913" DataType="Int16" BlockXSize="256" BlockYSize="256" />
+      <SrcRect xOff="0" yOff="0" xSize="2283" ySize="1913" />
+      <DstRect xOff="0" yOff="0" xSize="2283" ySize="1913" />
+      <NODATA>-999</NODATA>
+    </ComplexSource>
+  </VRTRasterBand>
+</VRTDataset>

tests/python_tests/raster_colormapped_test.py

@@ -0,0 +1,38 @@
+#coding=utf8
+import os
+import mapnik
+from utilities import execution_path
+from nose.tools import *
+
+def setup():
+    # All of the paths used are relative, if we run the tests
+    # from another directory we need to chdir()
+    os.chdir(execution_path('.'))
+
+def test_vrt_rendering():
+    m = mapnik.Map(512,512)
+    mapnik.load_map(m,'../data/good_maps/vrt_colortable.xml')
+    m.zoom_all()
+    im = mapnik.Image(512,512)
+    mapnik.render(m,im)
+    actual = '/tmp/vrt_colortable.png'
+    expected = 'images/support/vrt_colortable.png'
+    im.save(actual)
+    expected_im = mapnik.Image.open(expected)
+    eq_(im.tostring(),expected_im.tostring(), 'failed comparing actual (%s) and expected(%s)' % (actual,'tests/python_tests/'+ expected))
+
+def test_tif_rendering_nodata():
+    m = mapnik.Map(512,512)
+    mapnik.load_map(m,'../data/good_maps/tiff_colortable.xml')
+    m.zoom_all()
+    im = mapnik.Image(512,512)
+    mapnik.render(m,im)
+    actual = '/tmp/tif_colortable.png'
+    expected = 'images/support/tif_colortable.png'
+    im.save(actual)
+    expected_im = mapnik.Image.open(expected)
+    eq_(im.tostring(),expected_im.tostring(), 'failed comparing actual (%s) and expected(%s)' % (actual,'tests/python_tests/'+ expected))
+
+if __name__ == "__main__":
+    setup()
+    [eval(run)() for run in dir() if 'test_' in run]