[Feature][RASTER] Generate band name with NetCDF EXTRA_DIM funded by

Ifremer The NetCDF provided extra dimensional information. This information provides metadata on each band. These metadat can be used to explain the name of each band. For example, the bands of a NetCDF file represents the temperature at a given depth. For the user, it is easier to select a band with depth information, rather than the number. If the GDAL version is equal or greater than 1.10.0, the band name is generated with the extra_dim information.
qgis · Mar 18, 2014 · 82164b4 · 82164b4
1 parent ab920ba
commit 82164b4
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Showing 3 changed files with 74 additions and 1 deletion.
diff --git a/src/core/raster/qgsrasterinterface.h b/src/core/raster/qgsrasterinterface.h
@@ -97,7 +97,7 @@ class CORE_EXPORT QgsRasterInterface
     virtual int ySize() const { if ( mInput ) return mInput->ySize(); else return 0; }
 
     /** \brief helper function to create zero padded band names */
-    virtual QString  generateBandName( int theBandNumber ) const
+    virtual QString generateBandName( int theBandNumber ) const
     {
       return tr( "Band" ) + QString( " %1" ) .arg( theBandNumber,  1 + ( int ) log10(( float ) bandCount() ), 10, QChar( '0' ) );
     }

diff --git a/src/providers/gdal/qgsgdalprovider.cpp b/src/providers/gdal/qgsgdalprovider.cpp
@@ -47,6 +47,7 @@
 #include <QTime>
 #include <QSettings>
 #include <QTextDocument>
+#include <QDebug>
 
 #include "gdalwarper.h"
 #include "ogr_spatialref.h"
@@ -875,6 +876,76 @@ int QgsGdalProvider::yBlockSize() const
 int QgsGdalProvider::xSize() const { return mWidth; }
 int QgsGdalProvider::ySize() const { return mHeight; }
 
+QString QgsGdalProvider::generateBandName( int BandNo ) const
+{
+#ifdef GDAL_COMPUTE_VERSION /* only available in GDAL 1.10 or later */
+#if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(1,10,0) 
+  if ( strcmp( GDALGetDriverShortName( GDALGetDatasetDriver( mGdalDataset ) ), "netCDF" ) == 0 )
+  {
+    char ** GDALmetadata = GDALGetMetadata( mGdalDataset, NULL );
+
+    if ( GDALmetadata )
+    {
+      QStringList metadata = cStringList2Q_( GDALmetadata );
+      QStringList dimExtraValues;
+      QMap< QString, QString > unitsMap;
+      for ( QStringList::const_iterator i = metadata.begin();
+          i != metadata.end();
+          ++i )
+      {
+        QString val(*i);
+        if ( !val.startsWith( "NETCDF_DIM_EXTRA" ) && !val.contains( "#units=" ) )
+          continue;
+        QStringList values = val.split( "=" );
+        val = values.at( 1 );
+        if ( values.at( 0 ) == "NETCDF_DIM_EXTRA" ) {
+          dimExtraValues = val.replace(QString("{"), QString("")).replace(QString("}"), QString("")).split(",");
+          //http://qt-project.org/doc/qt-4.8/qregexp.html#capturedTexts
+        } else {
+          unitsMap[ values.at(0).split( "#" ).at(0) ] = val;
+        }
+      }
+      if ( dimExtraValues.count() > 0 )
+      {
+        QStringList bandNameValues;
+        GDALRasterBandH gdalBand = GDALGetRasterBand( mGdalDataset, BandNo );
+        GDALmetadata = GDALGetMetadata( gdalBand, NULL );
+
+        if ( GDALmetadata )
+        {
+          metadata = cStringList2Q_( GDALmetadata );
+          for ( QStringList::const_iterator i = metadata.begin();
+              i != metadata.end();
+              ++i )
+          {
+            QString val(*i);
+            if ( !val.startsWith( "NETCDF_DIM_" ) )
+              continue;
+            QStringList values = val.split( "=" );
+            for ( QStringList::const_iterator j = dimExtraValues.begin();
+                j != dimExtraValues.end();
+                ++j )
+            {
+              QString dim = (*j);
+              if ( values.at( 0 ) != "NETCDF_DIM_"+dim )
+                continue;
+              if ( unitsMap.contains( dim ) )
+                bandNameValues.append( values.at(1)+" "+unitsMap[ dim ] );
+              else
+                bandNameValues.append( values.at(1) );
+            }
+          }
+        }
+        if ( bandNameValues.count() > 0 )
+          return bandNameValues.join(" ");
+      }
+    }
+  }
+#endif
+#endif
+  return tr( "Band" ) + QString( " %1" ) .arg( BandNo,  1 + ( int ) log10(( float ) bandCount() ), 10, QChar( '0' ) );
+}
+
 QgsRasterIdentifyResult QgsGdalProvider::identify( const QgsPoint & thePoint, QgsRaster::IdentifyFormat theFormat, const QgsRectangle &theExtent, int theWidth, int theHeight )
 {
   QgsDebugMsg( QString( "thePoint =  %1 %2" ).arg( thePoint.x(), 0, 'g', 10 ).arg( thePoint.y(), 0, 'g', 10 ) );

diff --git a/src/providers/gdal/qgsgdalprovider.h b/src/providers/gdal/qgsgdalprovider.h
@@ -169,6 +169,8 @@ class QgsGdalProvider : public QgsRasterDataProvider, QgsGdalProviderBase
     int xSize() const;
     int ySize() const;
 
+    QString generateBandName( int theBandNumber ) const;
+
     /**Reimplemented from QgsRasterDataProvider to bypass second resampling (more efficient for local file based sources)*/
     QgsRasterBlock *block( int theBandNo, const QgsRectangle &theExtent, int theWidth, int theHeight );