nodata rendered transparent

Author: blazek

src/app/qgsrasterlayerproperties.cpp

@@ -1298,9 +1298,9 @@ void QgsRasterLayerProperties::pixelSelected( const QgsPoint& canvasPoint )
     mRasterLayer->identify( mMapCanvas->mapRenderer()->mapToLayerCoordinates( mRasterLayer, canvasPoint ), myPixelMap );
 
     QList<int> bands = renderer->usesBands();
-    tableTransparency->insertRow( tableTransparency->rowCount() );
-    setTransparencyCell( tableTransparency->rowCount() - 1, tableTransparency->columnCount() - 1, 100 );
+    delete renderer;
 
+    QList<double> values;
     for ( int i = 0; i < bands.size(); ++i )
     {
       QMap< int, QString >::const_iterator pixelResult = myPixelMap.find( bands.at( i ) );
@@ -1309,20 +1309,31 @@ void QgsRasterLayerProperties::pixelSelected( const QgsPoint& canvasPoint )
         QString value = pixelResult.value();
         if ( value != tr( "out of extent" ) )
         {
-          setTransparencyCell( tableTransparency->rowCount() - 1, i, value.toDouble() );
+          QgsDebugMsg( QString( "Is it %1 of band %2 nodata?" ).arg( value ).arg( bands.at( i ) ) );
+          if ( value == tr( "null (no data)" ) || // Very bad! TODO: improve identify
+               mRasterLayer->dataProvider()->isNoDataValue( bands.at( i ), value.toDouble() ) )
+          {
+            return; // Dont add nodata, transparent anyway
+          }
+          values.append( value.toDouble() );
         }
       }
     }
     if ( bands.size() == 1 )
     {
       // Set 'to'
-      setTransparencyCell( tableTransparency->rowCount() - 1, 1, transparencyCellValue( tableTransparency->rowCount() - 1, 0 ) );
+      values.insert( 1, values.value( 0 ) );
     }
+    tableTransparency->insertRow( tableTransparency->rowCount() );
+    for ( int i = 0; i < values.size(); i++ )
+    {
+      setTransparencyCell( tableTransparency->rowCount() - 1, i, values.value( i ) );
+    }
+    setTransparencyCell( tableTransparency->rowCount() - 1, tableTransparency->columnCount() - 1, 100 );
   }
 
   tableTransparency->resizeColumnsToContents();
   tableTransparency->resizeRowsToContents();
-  delete renderer;
 }
 
 void QgsRasterLayerProperties::sliderTransparency_valueChanged( int theValue )

src/core/raster/qgsmultibandcolorrenderer.cpp

@@ -234,22 +234,42 @@ void * QgsMultiBandColorRenderer::readBlock( int bandNo, QgsRectangle  const & e
         redVal = readValue( redData, redType, currentRasterPos );
         greenVal = readValue( greenData, greenType, currentRasterPos );
         blueVal = readValue( blueData, blueType, currentRasterPos );
-        imageScanLine[j] = qRgba( redVal, greenVal, blueVal, 255 );
+        if ( mInput->isNoDataValue( mRedBand, redVal ) ||
+             mInput->isNoDataValue( mGreenBand, greenVal ) ||
+             mInput->isNoDataValue( mBlueBand, blueVal ) )
+        {
+          imageScanLine[j] = defaultColor;
+        }
+        else
+        {
+          imageScanLine[j] = qRgba( redVal, greenVal, blueVal, 255 );
+        }
+
         ++currentRasterPos;
         continue;
       }
 
+      bool isNoData = false;
       if ( mRedBand > 0 )
       {
         redVal = readValue( redData, redType, currentRasterPos );
+        if ( mInput->isNoDataValue( mRedBand, redVal ) ) isNoData = true;
       }
       if ( mGreenBand > 0 )
       {
         greenVal = readValue( greenData, greenType, currentRasterPos );
+        if ( mInput->isNoDataValue( mGreenBand, greenVal ) ) isNoData = true;
       }
       if ( mBlueBand > 0 )
       {
         blueVal = readValue( blueData, blueType, currentRasterPos );
+        if ( mInput->isNoDataValue( mBlueBand, blueVal ) ) isNoData = true;
+      }
+      if ( isNoData )
+      {
+        imageScanLine[j] = defaultColor;
+        ++currentRasterPos;
+        continue;
       }
 
       //apply default color if red, green or blue not in displayable range

src/core/raster/qgspalettedrasterrenderer.cpp

@@ -93,6 +93,7 @@ void * QgsPalettedRasterRenderer::readBlock( int bandNo, QgsRectangle  const & e
   {
     return 0;
   }
+  QRgb myDefaultColor = qRgba( 0, 0, 0, 0 );
 
   QgsRasterInterface::DataType transparencyType = QgsRasterInterface::UnknownDataType;
   if ( mAlphaBand > 0 )
@@ -129,6 +130,12 @@ void * QgsPalettedRasterRenderer::readBlock( int bandNo, QgsRectangle  const & e
     for ( int j = 0; j < width; ++j )
     {
       val = readValue( rasterData, rasterType, currentRasterPos );
+      if ( mInput->isNoDataValue( mBandNumber, val ) )
+      {
+        imageScanLine[j] = myDefaultColor;
+        ++currentRasterPos;
+        continue;
+      }
       if ( !hasTransparency )
       {
         imageScanLine[j] = mColors[ val ].rgba();

src/core/raster/qgsrasterinterface.cpp

@@ -120,6 +120,18 @@ QgsRasterInterface::DataType QgsRasterInterface::typeWithNoDataValue( DataType d
   return newDataType;
 }
 
+inline bool QgsRasterInterface::isNoDataValue( int bandNo, double value ) const
+{
+  // More precise would be qIsNaN(value) && qIsNaN(noDataValue(bandNo)), but probably
+  // not important and slower
+  if ( qIsNaN( value ) ||
+       doubleNear( value, noDataValue( bandNo ) ) )
+  {
+    return true;
+  }
+  return false;
+}
+
 // To give to an image preallocated memory is the only way to avoid memcpy
 // when we want to keep data but delete QImage
 QImage * QgsRasterInterface::createImage( int width, int height, QImage::Format format )

src/core/raster/qgsrasterinterface.h

@@ -125,8 +125,22 @@ class CORE_EXPORT QgsRasterInterface
     }
 
     /** Retruns value representing 'no data' (NULL) */
+    // TODO: Q_DECL_DEPRECATED
     virtual double noDataValue() const { return 0; }
 
+    /** Return no data value for specific band. Each band/provider must have
+     * no data value, if there is no one set in original data, provider decides one
+     * possibly using wider data type.
+     * @param bandNo band number
+     * @return No data value */
+    virtual double noDataValue( int bandNo ) const { Q_UNUSED( bandNo ); return noDataValue(); }
+
+    /** Test if value is nodata for specific band
+     * @param bandNo band number
+     * @param value tested value
+     * @return true if value is nodata */
+    virtual bool isNoDataValue( int bandNo, double value ) const ;
+
     /** Read block of data using given extent and size.
      *  Returns pointer to data.
      *  Caller is responsible to free the memory returned.

src/core/raster/qgsrastertransparency.cpp

@@ -178,11 +178,17 @@ bool QgsRasterTransparency::isEmpty( double nodataValue ) const
 {
   return (
            ( mTransparentSingleValuePixelList.isEmpty() ||
-             ( mTransparentSingleValuePixelList.size() == 1 && doubleNear( mTransparentSingleValuePixelList.at( 0 ).min, nodataValue ) && doubleNear( mTransparentSingleValuePixelList.at( 0 ).max, nodataValue ) ) )
+             ( mTransparentSingleValuePixelList.size() == 1 &&
+               ( doubleNear( mTransparentSingleValuePixelList.at( 0 ).min, nodataValue ) ||
+                 doubleNear( mTransparentSingleValuePixelList.at( 0 ).max, nodataValue ) ||
+                 ( nodataValue > mTransparentSingleValuePixelList.at( 0 ).min &&
+                   nodataValue < mTransparentSingleValuePixelList.at( 0 ).max ) ) ) )
            &&
            ( mTransparentThreeValuePixelList.isEmpty() ||
-             ( mTransparentThreeValuePixelList.size() < 4 && doubleNear( mTransparentThreeValuePixelList.at( 0 ).red, nodataValue ) &&
-               doubleNear( mTransparentThreeValuePixelList.at( 0 ).green, nodataValue ) && doubleNear( mTransparentThreeValuePixelList.at( 0 ).blue, nodataValue ) ) ) );
+             ( mTransparentThreeValuePixelList.size() == 1 &&
+               doubleNear( mTransparentThreeValuePixelList.at( 0 ).red, nodataValue ) &&
+               doubleNear( mTransparentThreeValuePixelList.at( 0 ).green, nodataValue ) &&
+               doubleNear( mTransparentThreeValuePixelList.at( 0 ).blue, nodataValue ) ) ) );
 }
 
 void QgsRasterTransparency::writeXML( QDomDocument& doc, QDomElement& parentElem ) const

src/core/raster/qgssinglebandgrayrenderer.cpp

@@ -118,6 +118,13 @@ void * QgsSingleBandGrayRenderer::readBlock( int bandNo, QgsRectangle  const & e
     {
       grayVal = readValue( rasterData, rasterType, currentRasterPos );
 
+      if ( mInput->isNoDataValue( mGrayBand, grayVal ) )
+      {
+        imageScanLine[j] = myDefaultColor;
+        ++currentRasterPos;
+        continue;
+      }
+
       //alpha
       currentAlpha = mOpacity;
       if ( mRasterTransparency )

src/core/raster/qgssinglebandpseudocolorrenderer.cpp

@@ -117,6 +117,12 @@ void * QgsSingleBandPseudoColorRenderer::readBlock( int bandNo, QgsRectangle  co
     for ( int j = 0; j < width; ++j )
     {
       val = readValue( rasterData, rasterType, currentRasterPos );
+      if ( mInput->isNoDataValue( mBand, val ) )
+      {
+        imageScanLine[j] = myDefaultColor;
+        ++currentRasterPos;
+        continue;
+      }
       if ( !mShader->shade( val, &red, &green, &blue ) )
       {
         imageScanLine[j] = myDefaultColor;