[FEATURE] brightness and contrast filter for rasters

src/app/qgisapp.cpp

@@ -169,6 +169,7 @@
 #include "qgsrasterlayer.h"
 #include "qgsrasterlayerproperties.h"
 #include "qgsrasternuller.h"
+#include "qgsbrightnesscontrastfilter.h"
 #include "qgsrasterrenderer.h"
 #include "qgsrasterlayersaveasdialog.h"
 #include "qgsrectangle.h"
@@ -1050,6 +1051,10 @@ void QgisApp::createActions()
   connect( mActionFullHistogramStretch, SIGNAL( triggered() ), this, SLOT( fullHistogramStretch() ) );
   connect( mActionLocalCumulativeCutStretch, SIGNAL( triggered() ), this, SLOT( localCumulativeCutStretch() ) );
   connect( mActionFullCumulativeCutStretch, SIGNAL( triggered() ), this, SLOT( fullCumulativeCutStretch() ) );
+  connect( mActionIncreaseBrightness, SIGNAL( triggered() ), this, SLOT( increaseBrightness() ) );
+  connect( mActionDecreaseBrightness, SIGNAL( triggered() ), this, SLOT( decreaseBrightness() ) );
+  connect( mActionIncreaseContrast, SIGNAL( triggered() ), this, SLOT( increaseContrast() ) );
+  connect( mActionDecreaseContrast, SIGNAL( triggered() ), this, SLOT( decreaseContrast() ) );
 
   // Vector Menu Items
   connect( mActionOSMDownload, SIGNAL( triggered() ), this, SLOT( osmDownloadDialog() ) );
@@ -1675,6 +1680,10 @@ void QgisApp::setTheme( QString theThemeName )
   mActionHelpContents->setIcon( QgsApplication::getThemeIcon( "/mActionHelpContents.png" ) );
   mActionLocalHistogramStretch->setIcon( QgsApplication::getThemeIcon( "/mActionLocalHistogramStretch.png" ) );
   mActionFullHistogramStretch->setIcon( QgsApplication::getThemeIcon( "/mActionFullHistogramStretch.png" ) );
+  //~ mActionIncreaseBrightness->setIcon( QgsApplication::getThemeIcon( "/mActionIncreaseBrightness.png" ) );
+  //~ mActionDecreaseBrightness->setIcon( QgsApplication::getThemeIcon( "/mActionDecreaseBrightness.png" ) );
+  //~ mActionIncreaseContrast->setIcon( QgsApplication::getThemeIcon( "/mActionIncreaseContrast.png" ) );
+  //~ mActionDecreaseContrast->setIcon( QgsApplication::getThemeIcon( "/mActionDecreaseContrast.png" ) );
   mActionZoomActualSize->setIcon( QgsApplication::getThemeIcon( "/mActionZoomNative.png" ) );
   mActionQgisHomePage->setIcon( QgsApplication::getThemeIcon( "/mActionQgisHomePage.png" ) );
   mActionAbout->setIcon( QgsApplication::getThemeIcon( "/mActionHelpAbout.png" ) );
@@ -6454,6 +6463,63 @@ void QgisApp::histogramStretch( bool visibleAreaOnly, QgsRasterLayer::ContrastEn
   mMapCanvas->refresh();
 }
 
+void QgisApp::increaseBrightness()
+{
+  adjustBrightnessContrast( 1 );
+}
+
+void QgisApp::decreaseBrightness()
+{
+  adjustBrightnessContrast( -1 );
+}
+
+void QgisApp::increaseContrast()
+{
+  adjustBrightnessContrast( 1, false );
+}
+
+void QgisApp::decreaseContrast()
+{
+  adjustBrightnessContrast( -1, false );
+}
+
+
+void QgisApp::adjustBrightnessContrast( int delta, bool updateBrightness )
+{
+  QgsMapLayer * myLayer = mMapLegend->currentLayer();
+
+  if ( !myLayer )
+  {
+    QMessageBox::information( this,
+                              tr( "No Layer Selected" ),
+                              tr( "To change brightness or contrast, you need to have a raster layer selected." ) );
+    return;
+  }
+
+  QgsRasterLayer* myRasterLayer = qobject_cast<QgsRasterLayer *>( myLayer );
+  if ( !myRasterLayer )
+  {
+    QMessageBox::information( this,
+                              tr( "No Raster Layer Selected" ),
+                              tr( "To change brightness or contrast, you need to have a raster layer selected." ) );
+    return;
+  }
+
+  QgsBrightnessContrastFilter* brightnessFilter = myRasterLayer->brightnessFilter();
+
+  if ( updateBrightness )
+  {
+    brightnessFilter->setBrightness( brightnessFilter->brightness() + delta );
+  }
+  else
+  {
+    brightnessFilter->setContrast( brightnessFilter->contrast() + delta );
+  }
+
+  myRasterLayer->setCacheImage( NULL );
+  mMapCanvas->refresh();
+}
+
 void QgisApp::helpContents()
 {
   openURL( "index.html" );

src/app/qgisapp.h

@@ -670,6 +670,22 @@ class QgisApp : public QMainWindow, private Ui::MainWindow
     void localCumulativeCutStretch();
     /** Perform a full extent cumulative cut stretch */
     void fullCumulativeCutStretch();
+    /**Increase raster brightness
+     * Valid for non wms raster layers only.
+     * @note Added in QGIS 2.0 */
+    void increaseBrightness();
+    /**Decrease raster brightness
+     * Valid for non wms raster layers only.
+     * @note Added in QGIS 2.0 */
+    void decreaseBrightness();
+    /**Increase raster contrast
+     * Valid for non wms raster layers only.
+     * @note Added in QGIS 2.0 */
+    void increaseContrast();
+    /**Decrease raster contrast
+     * Valid for non wms raster layers only.
+     * @note Added in QGIS 2.0 */
+    void decreaseContrast();
     //! plugin manager
     void showPluginManager();
     //! load python support if possible
@@ -1143,6 +1159,10 @@ class QgisApp : public QMainWindow, private Ui::MainWindow
     /**Do histogram stretch for singleband gray / multiband color rasters*/
     void histogramStretch( bool visibleAreaOnly = false, QgsRasterLayer::ContrastEnhancementLimits theLimits = QgsRasterLayer::ContrastEnhancementMinMax );
 
+    /**Apply raster brightness
+     * @note Added in QGIS 2.0 */
+    void adjustBrightnessContrast( int delta, bool updateBrightness = true );
+
     QgisAppStyleSheet* mStyleSheetBuilder;
 
     // actions for menus and toolbars -----------------

src/core/CMakeLists.txt

@@ -40,12 +40,12 @@ SET(QGIS_CORE_SRCS
   symbology-ng/qgspointdisplacementrenderer.cpp
   symbology-ng/qgsvectorfieldsymbollayer.cpp
   symbology-ng/qgscolorbrewerpalette.cpp
-  
+
   diagram/qgsdiagram.cpp
   diagram/qgspiediagram.cpp
   diagram/qgstextdiagram.cpp
   diagram/qgshistogramdiagram.cpp
-  
+
   qgis.cpp
   qgsapplication.cpp
   qgsattributeaction.cpp
@@ -204,6 +204,7 @@ SET(QGIS_CORE_SRCS
   raster/qgssinglebandcolordatarenderer.cpp
   raster/qgssinglebandgrayrenderer.cpp
   raster/qgssinglebandpseudocolorrenderer.cpp
+  raster/qgsbrightnesscontrastfilter.cpp
 
   renderer/qgscontinuouscolorrenderer.cpp
   renderer/qgsgraduatedsymbolrenderer.cpp
@@ -446,7 +447,7 @@ SET(QGIS_CORE_HDRS
   diagram/qgstextdiagram.h
   diagram/qgshistogramdiagram.h
 
-  
+
   composer/qgslegendmodel.h
   composer/qgscomposerlegenditem.h
 

src/core/raster/qgsbrightnesscontrastfilter.cpp

@@ -0,0 +1,195 @@
+/***************************************************************************
+                         qgsbrightnesscontrastfilter.cpp
+                         ---------------------
+    begin                : February 2013
+    copyright            : (C) 2013 by Alexander Bruy
+    email                : alexander dot bruy at gmail dot com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsrasterdataprovider.h"
+#include "qgsbrightnesscontrastfilter.h"
+
+#include <QDomDocument>
+#include <QDomElement>
+
+
+QgsBrightnessContrastFilter::QgsBrightnessContrastFilter( QgsRasterInterface* input )
+    : QgsRasterInterface( input ),
+    mBrightness( 0 ),
+    mContrast( 0 )
+{
+}
+
+QgsBrightnessContrastFilter::~QgsBrightnessContrastFilter()
+{
+}
+
+QgsRasterInterface * QgsBrightnessContrastFilter::clone() const
+{
+  QgsDebugMsg( "Entered" );
+  QgsBrightnessContrastFilter * filter = new QgsBrightnessContrastFilter( 0 );
+  filter->setBrightness( mBrightness );
+  return filter;
+}
+
+int QgsBrightnessContrastFilter::bandCount() const
+{
+  if ( mOn )
+  {
+    return 1;
+  }
+
+  if ( mInput )
+  {
+    return mInput->bandCount();
+  }
+
+  return 0;
+}
+
+QGis::DataType QgsBrightnessContrastFilter::dataType( int bandNo ) const
+{
+  if ( mOn )
+  {
+    return QGis::ARGB32_Premultiplied;
+  }
+
+  if ( mInput )
+  {
+    return mInput->dataType( bandNo );
+  }
+
+  return QGis::UnknownDataType;
+}
+
+bool QgsBrightnessContrastFilter::setInput( QgsRasterInterface* input )
+{
+  QgsDebugMsg( "Entered" );
+
+  // Brightness filter can only work with single band ARGB32_Premultiplied
+  if ( !input )
+  {
+    QgsDebugMsg( "No input" );
+    return false;
+  }
+
+  if ( !mOn )
+  {
+    // In off mode we can connect to anything
+    QgsDebugMsg( "OK" );
+    mInput = input;
+    return true;
+  }
+
+  if ( input->bandCount() < 1 )
+  {
+    QgsDebugMsg( "No input band" );
+    return false;
+  }
+
+  if ( input->dataType( 1 ) != QGis::ARGB32_Premultiplied &&
+       input->dataType( 1 ) != QGis::ARGB32 )
+  {
+    QgsDebugMsg( "Unknown input data type" );
+    return false;
+  }
+
+  mInput = input;
+  QgsDebugMsg( "OK" );
+  return true;
+}
+
+QgsRasterBlock * QgsBrightnessContrastFilter::block( int bandNo, QgsRectangle  const & extent, int width, int height )
+{
+  Q_UNUSED( bandNo );
+  QgsDebugMsg( "Entered" );
+
+  QgsRasterBlock *outputBlock = new QgsRasterBlock();
+  if ( !mInput )
+  {
+    return outputBlock;
+  }
+
+  // At this moment we know that we read rendered image
+  int bandNumber = 1;
+  QgsRasterBlock *inputBlock = mInput->block( bandNumber, extent, width, height );
+  if ( !inputBlock || inputBlock->isEmpty() )
+  {
+    QgsDebugMsg( "No raster data!" );
+    delete inputBlock;
+    return outputBlock;
+  }
+
+  if ( mBrightness == 0 && mContrast == 0 )
+  {
+    QgsDebugMsg( "No brightness changes." );
+    delete outputBlock;
+    return inputBlock;
+  }
+
+  if ( !outputBlock->reset( QGis::ARGB32_Premultiplied, width, height ) )
+  {
+    delete inputBlock;
+    return outputBlock;
+  }
+
+  // adjust image
+  QRgb myNoDataColor = qRgba( 0, 0, 0, 0 );
+  QRgb myColor;
+  int r, g, b;
+
+  double f = ( 259 * ( mContrast + 255 ) ) / ( 255 * ( 259 - mContrast ) );
+
+  for ( size_t i = 0; i < ( size_t )width*height; i++ )
+  {
+    if ( inputBlock->color( i ) == myNoDataColor )
+    {
+      outputBlock->setColor( i, myNoDataColor );
+      continue;
+    }
+
+    myColor = inputBlock->color( i );
+    r = qBound( 0, qRound( f * ( qBound( 0, qRed( myColor ) + mBrightness, 255 ) - 128 ) + 128 ), 255 );
+    g = qBound( 0, qRound( f * ( qBound( 0, qGreen( myColor ) + mBrightness, 255 ) - 128 ) + 128 ), 255 );
+    b = qBound( 0, qRound( f * ( qBound( 0, qBlue( myColor ) + mBrightness, 255 ) - 128 ) + 128 ), 255 );
+
+    outputBlock->setColor( i, qRgb( r, g, b ) );
+  }
+
+  delete inputBlock;
+  return outputBlock;
+}
+
+void QgsBrightnessContrastFilter::writeXML( QDomDocument& doc, QDomElement& parentElem )
+{
+  if ( parentElem.isNull() )
+  {
+    return;
+  }
+
+  QDomElement filterElem = doc.createElement( "brightnesscontrast" );
+
+  filterElem.setAttribute( "brightness", QString::number( mBrightness ) );
+  filterElem.setAttribute( "contrast", QString::number( mContrast ) );
+  parentElem.appendChild( filterElem );
+}
+
+void QgsBrightnessContrastFilter::readXML( const QDomElement& filterElem )
+{
+  if ( filterElem.isNull() )
+  {
+    return;
+  }
+
+  mBrightness = filterElem.attribute( "brightness", "0" ).toInt();
+  mContrast = filterElem.attribute( "contrast", "0" ).toInt();
+}