cumulative cut tools, raster stretching moved from qgisapp to raster layer, unfortunately one control image has also be changed because stretching changed from GDALComputeRasterMinMax which gives for tests/testdata/landsat.tif 3. band min/max 57/157 to GDALComputeRasterStatistics which gives 51/172

Author: blazek

images/images.qrc

@@ -79,6 +79,7 @@
     <file>themes/default/mActionFormAnnotation.png</file>
     <file>themes/default/mActionFreezeLabels.png</file>
     <file>themes/default/mActionFromSelectedFeature.png</file>
+    <file>themes/default/mActionFullCumulativeCutStretch.png</file>
     <file>themes/default/mActionFullHistogramStretch.png</file>
     <file>themes/default/mActionGroupItems.png</file>
     <file>themes/default/mActionHelpAbout.png</file>
@@ -91,6 +92,7 @@
     <file>themes/default/mActionInvertSelection.png</file>
     <file>themes/default/mActionLabeling.png</file>
     <file>themes/default/mActionLabel.png</file>
+    <file>themes/default/mActionLocalCumulativeCutStretch.png</file>
     <file>themes/default/mActionLocalHistogramStretch.png</file>
     <file>themes/default/mActionLowerItems.png</file>
     <file>themes/default/mActionMapTips.png</file>

images/themes/default/mActionFullCumulativeCutStretch.png

@@ -963,6 +963,8 @@ void QgisApp::createActions()
   // Raster toolbar items
   connect( mActionLocalHistogramStretch, SIGNAL( triggered() ), this, SLOT( localHistogramStretch() ) );
   connect( mActionFullHistogramStretch, SIGNAL( triggered() ), this, SLOT( fullHistogramStretch() ) );
+  connect( mActionLocalCumulativeCutStretch, SIGNAL( triggered() ), this, SLOT( localCumulativeCutStretch() ) );
+  connect( mActionFullCumulativeCutStretch, SIGNAL( triggered() ), this, SLOT( fullCumulativeCutStretch() ) );
 
   // Help Menu Items
 
@@ -5461,142 +5463,53 @@ void QgisApp::options()
 
 void QgisApp::fullHistogramStretch()
 {
-  histogramStretch( false );
+  histogramStretch( false, QgsRasterLayer::ContrastEnhancementMinMax );
 }
 
-void QgisApp::histogramStretch( bool visibleAreaOnly )
+void QgisApp::localHistogramStretch()
 {
-  QgsMapLayer * layer = mMapLegend->currentLayer();
+  histogramStretch( true, QgsRasterLayer::ContrastEnhancementMinMax );
+}
 
-  if ( !layer )
+void QgisApp::fullCumulativeCutStretch()
+{
+  histogramStretch( false, QgsRasterLayer::ContrastEnhancementCumulativeCut );
+}
+
+void QgisApp::localCumulativeCutStretch()
+{
+  histogramStretch( true, QgsRasterLayer::ContrastEnhancementCumulativeCut );
+}
+
+void QgisApp::histogramStretch( bool visibleAreaOnly, QgsRasterLayer::ContrastEnhancementLimits theLimits )
+{
+  QgsMapLayer * myLayer = mMapLegend->currentLayer();
+
+  if ( !myLayer )
   {
     QMessageBox::information( this,
                               tr( "No Layer Selected" ),
                               tr( "To perform a full histogram stretch, you need to have a raster layer selected." ) );
     return;
   }
 
-  QgsRasterLayer* rlayer = qobject_cast<QgsRasterLayer *>( layer );
-  if ( !rlayer )
+  QgsRasterLayer* myRasterLayer = qobject_cast<QgsRasterLayer *>( myLayer );
+  if ( !myRasterLayer )
   {
     QMessageBox::information( this,
                               tr( "No Raster Layer Selected" ),
                               tr( "To perform a full histogram stretch, you need to have a raster layer selected." ) );
     return;
   }
 
-  QgsRasterDataProvider* provider = rlayer->dataProvider();
-  if ( !provider )
-  {
-    return;
-  }
-
-  //get renderer
-  QgsRasterRenderer* renderer = rlayer->renderer();
-  if ( !renderer )
-  {
-    return;
-  }
-
-  //singleband gray <-> multiband color
-  if ( renderer->type() == "singlebandgray" )
-  {
-    QgsSingleBandGrayRenderer* grayRenderer = static_cast<QgsSingleBandGrayRenderer*>( renderer );
-    if ( !grayRenderer )
-    {
-      return;
-    }
-
-    //create new contrast enhancements
-    int grayBand = grayRenderer->grayBand();
-    if ( grayBand == -1 )
-    {
-      return;
-    }
-
-    QgsContrastEnhancement* e = rasterContrastEnhancement( rlayer, grayBand, visibleAreaOnly );
-    if ( !e )
-    {
-      return;
-    }
-    grayRenderer->setContrastEnhancement( e );
-  }
-  else if ( renderer->type() == "multibandcolor" )
-  {
-    QgsMultiBandColorRenderer* colorRenderer = static_cast<QgsMultiBandColorRenderer*>( renderer );
-    if ( !colorRenderer )
-    {
-      return;
-    }
+  QgsRectangle myRectangle;
+  if ( visibleAreaOnly ) myRectangle = mMapCanvas->mapRenderer()->outputExtentToLayerExtent( myRasterLayer, mMapCanvas->extent() );
 
-    QgsContrastEnhancement* redEnhancement = rasterContrastEnhancement( rlayer, colorRenderer->redBand(), visibleAreaOnly );
-    if ( redEnhancement )
-    {
-      colorRenderer->setRedContrastEnhancement( redEnhancement );
-    }
-    QgsContrastEnhancement* greenEnhancement = rasterContrastEnhancement( rlayer, colorRenderer->greenBand(), visibleAreaOnly );
-    if ( greenEnhancement )
-    {
-      colorRenderer->setGreenContrastEnhancement( greenEnhancement );
-    }
-    QgsContrastEnhancement* blueEnhancement = rasterContrastEnhancement( rlayer, colorRenderer->blueBand(), visibleAreaOnly );
-    if ( blueEnhancement )
-    {
-      colorRenderer->setBlueContrastEnhancement( blueEnhancement );
-    }
-  }
-  else
-  {
-    return;
-  }
+  myRasterLayer->setContrastEnhancementAlgorithm( QgsContrastEnhancement::StretchToMinimumMaximum, theLimits, myRectangle );
 
   mMapCanvas->refresh();
 }
 
-QgsContrastEnhancement* QgisApp::rasterContrastEnhancement( QgsRasterLayer* rlayer, int band,
-    bool visibleAreaOnly ) const
-{
-  if ( !rlayer || band == -1 )
-  {
-    return 0;
-  }
-
-  QgsRasterDataProvider* provider = rlayer->dataProvider();
-  if ( !provider )
-  {
-    return 0;
-  }
-
-  QgsContrastEnhancement* e = new QgsContrastEnhancement(( QgsContrastEnhancement::QgsRasterDataType )(
-        provider->dataType( band ) ) );
-  double minValue = 0;
-  double maxValue = 0;
-
-  if ( visibleAreaOnly )
-  {
-    double minMax[2];
-    rlayer->computeMinimumMaximumFromLastExtent( band, minMax );
-    minValue = minMax[0];
-    maxValue = minMax[1];
-  }
-  else
-  {
-    QgsRasterBandStats rasterBandStats = rlayer->dataProvider()->bandStatistics( band );
-    minValue = rasterBandStats.minimumValue;
-    maxValue = rasterBandStats.maximumValue;
-  }
-
-  e->setMinimumValue( minValue );
-  e->setMaximumValue( maxValue );
-  e->setContrastEnhancementAlgorithm( QgsContrastEnhancement::StretchToMinimumMaximum );
-  return e;
-}
-
-void QgisApp::localHistogramStretch()
-{
-  histogramStretch( true );
-}
-
 void QgisApp::helpContents()
 {
   openURL( "index.html" );

images/themes/default/mActionLocalCumulativeCutStretch.png

@@ -55,7 +55,6 @@ class QgsPalLabeling;
 class QgsPoint;
 class QgsProviderRegistry;
 class QgsPythonUtils;
-class QgsRasterLayer;
 class QgsRectangle;
 class QgsUndoWidget;
 class QgsVectorLayer;
@@ -87,6 +86,7 @@ class QgsTileScaleWidget;
 #include "qgsconfig.h"
 #include "qgsfeature.h"
 #include "qgspoint.h"
+#include "qgsrasterlayer.h"
 #include "qgssnappingdialog.h"
 
 #include "ui_qgisapp.h"
@@ -548,6 +548,10 @@ class QgisApp : public QMainWindow, private Ui::MainWindow
      * Valid for non wms raster layers only.
      * @note Added in QGIS 1.7 */
     void fullHistogramStretch();
+    /** Perform a local cumulative cut stretch */
+    void localCumulativeCutStretch();
+    /** Perform a full extent cumulative cut stretch */
+    void fullCumulativeCutStretch();
     //! plugin manager
     void showPluginManager();
     //! load python support if possible
@@ -992,10 +996,7 @@ class QgisApp : public QMainWindow, private Ui::MainWindow
     void createDecorations();
 
     /**Do histogram stretch for singleband gray / multiband color rasters*/
-    void histogramStretch( bool visibleAreaOnly = false );
-    /**Create raster enhancement object for a raster band*/
-    QgsContrastEnhancement* rasterContrastEnhancement( QgsRasterLayer* rlayer, int band,
-        bool visibleAreaOnly = false ) const;
+    void histogramStretch( bool visibleAreaOnly = false, QgsRasterLayer::ContrastEnhancementLimits theLimits = QgsRasterLayer::ContrastEnhancementMinMax );
 
     // actions for menus and toolbars -----------------
 

src/app/qgisapp.cpp

@@ -435,7 +435,15 @@ void QgsRasterDataProvider::initStatistics( QgsRasterBandStats &theStatistics,
   theStatistics.bandNumber = theBandNo;
   theStatistics.statsGathered = theStats;
 
-  QgsRectangle myExtent = theExtent.isEmpty() ? extent() : theExtent;
+  QgsRectangle myExtent;
+  if ( theExtent.isEmpty() )
+  {
+    myExtent = extent();
+  }
+  else
+  {
+    myExtent = extent().intersect( &theExtent );
+  }
   theStatistics.extent = myExtent;
 
   if ( theSampleSize > 0 )
@@ -674,7 +682,15 @@ void QgsRasterDataProvider::initHistogram( QgsRasterHistogram &theHistogram,
     }
   }
 
-  QgsRectangle myExtent = theExtent.isEmpty() ? extent() : theExtent;
+  QgsRectangle myExtent;
+  if ( theExtent.isEmpty() )
+  {
+    myExtent = extent();
+  }
+  else
+  {
+    myExtent = extent().intersect( &theExtent );
+  }
   theHistogram.extent = myExtent;
 
   if ( theSampleSize > 0 )