Index: src/plugins/georeferencer/qgsgcpcanvasitem.cpp
===================================================================
--- src/plugins/georeferencer/qgsgcpcanvasitem.cpp	(revision 13226)
+++ src/plugins/georeferencer/qgsgcpcanvasitem.cpp	(working copy)
@@ -15,19 +15,20 @@
 /* $Id$ */
 
 #include "qgsgcpcanvasitem.h"
+#include "qgsgeorefdatapoint.h"
+#include "qgsmaplayerregistry.h"
+#include "qgsmaprenderer.h"
+#include "qgsrasterlayer.h"
 
-QgsGCPCanvasItem::QgsGCPCanvasItem( QgsMapCanvas* mapCanvas, const QgsPoint& rasterCoords,
-                                    const QgsPoint& worldCoords, bool isGCPSource )
-    : QgsMapCanvasItem( mapCanvas )
+QgsGCPCanvasItem::QgsGCPCanvasItem( QgsMapCanvas* mapCanvas, const QgsGeorefDataPoint* dataPoint, bool isGCPSource )
+    : QgsMapCanvasItem( mapCanvas ), mDataPoint( dataPoint )
     , mPointBrush( Qt::red )
     , mLabelBrush( Qt::yellow )
-    , mRasterCoords( rasterCoords )
-    , mWorldCoords( worldCoords )
-    , mId( -1 )
     , mIsGCPSource( isGCPSource )
-    , mEnabled( true )
 {
   setFlags( QGraphicsItem::ItemIsMovable );
+  mResidualPen.setColor( QColor( 255, 0, 0 ) );
+  mResidualPen.setWidthF( 2.0 );
 
   updatePosition();
 }
@@ -35,8 +36,20 @@
 void QgsGCPCanvasItem::paint( QPainter* p )
 {
   p->setRenderHint( QPainter::Antialiasing );
-  p->setOpacity( mEnabled ? 1.0 : 0.3 );
 
+  bool enabled = true;
+  QgsPoint worldCoords;
+  int id = -1;
+
+  if ( mDataPoint )
+  {
+    enabled = mDataPoint->isEnabled();
+    worldCoords = mDataPoint->mapCoords();
+    id = mDataPoint->id();
+  }
+
+  p->setOpacity( enabled ? 1.0 : 0.3 );
+
   // draw the point
   p->setPen( Qt::black );
   p->setBrush( mPointBrush );
@@ -46,8 +59,8 @@
   bool showIDs = s.value( "/Plugin-GeoReferencer/Config/ShowId" ).toBool();
   if ( !showIDs && mIsGCPSource )
   {
-    QString msg = QString( "X %1\nY %2" ).arg( QString::number( mWorldCoords.x(), 'f' ) ).
-                  arg( QString::number( mWorldCoords.y(), 'f' ) );
+    QString msg = QString( "X %1\nY %2" ).arg( QString::number( worldCoords.x(), 'f' ) ).
+                  arg( QString::number( worldCoords.y(), 'f' ) );
     p->setFont( QFont( "helvetica", 9 ) );
     QRect textBounds = p->boundingRect( 6, 6, 10, 10, Qt::AlignLeft, msg );
     p->setBrush( mLabelBrush );
@@ -58,20 +71,52 @@
   else if ( showIDs )
   {
     p->setFont( QFont( "helvetica", 12 ) );
-    QString msg = QString::number( mId );
+    QString msg = QString::number( id );
     p->setBrush( mLabelBrush );
     p->drawRect( 5, 4, p->fontMetrics().width( msg ) + 2, 14 );
     p->drawText( 6, 16, msg );
     QFontMetrics fm = p->fontMetrics();
     mTextBounds = QSize( fm.width( msg ) + 4, fm.height() + 4 );
   }
-  //  else
-  //    mTextBounds = QSizeF(0, 0);
+
+  drawResidualArrow( p );
 }
 
 QRectF QgsGCPCanvasItem::boundingRect() const
 {
-  return QRectF( -2, -2, mTextBounds.width() + 6, mTextBounds.height() + 6 );
+  double residualLeft, residualRight, residualTop, residualBottom;
+
+  QPointF residual;
+  if ( mDataPoint )
+  {
+    residual = mDataPoint->residual();
+  }
+  double rf = residualToScreenFactor();
+
+  if ( residual.x() > 0 )
+  {
+    residualRight = residual.x() * rf + mResidualPen.widthF();
+    residualLeft = -mResidualPen.widthF();
+  }
+  else
+  {
+    residualLeft = residual.x() * rf - mResidualPen.widthF();
+    residualRight = mResidualPen.widthF();
+  }
+  if ( residual.y() > 0 )
+  {
+    residualBottom = residual.y() * rf + mResidualPen.widthF();
+    residualTop = -mResidualPen.widthF();
+  }
+  else
+  {
+    residualBottom = mResidualPen.widthF();
+    residualTop = residual.y() * rf - mResidualPen.widthF();
+  }
+
+  QRectF residualArrowRect( QPointF( residualLeft, residualTop ), QPointF( residualRight, residualBottom ) );
+  QRectF markerRect( -2, -2, mTextBounds.width() + 6, mTextBounds.height() + 6 );
+  return residualArrowRect.united( markerRect );
 }
 
 QPainterPath QgsGCPCanvasItem::shape() const
@@ -83,31 +128,63 @@
   return p;
 }
 
-void QgsGCPCanvasItem::setEnabled( bool enabled )
+void QgsGCPCanvasItem::updatePosition()
 {
-  mEnabled = enabled;
-  mPointBrush = enabled ? QBrush( Qt::red ) : QBrush( Qt::gray );
-  mLabelBrush = enabled ? QBrush( Qt::yellow ) : QBrush( Qt::gray );
-  update();
+  if ( !mDataPoint )
+  {
+    return;
+  }
+
+  setPos( toCanvasCoordinates( mIsGCPSource ? mDataPoint->pixelCoords() : mDataPoint->mapCoords() ) );
 }
 
-void QgsGCPCanvasItem::setRasterCoords( QgsPoint p )
+void QgsGCPCanvasItem::drawResidualArrow( QPainter* p )
 {
-  mRasterCoords = p;
+  if ( !mDataPoint || !mIsGCPSource )
+  {
+    return;
+  }
+
+  QPointF residual = mDataPoint->residual();
+
+  double rf = residualToScreenFactor();
+  p->setPen( mResidualPen );
+  p->drawLine( QPointF( 0, 0 ), QPointF( residual.rx() * rf, residual.ry() * rf ) );
+
 }
 
-void QgsGCPCanvasItem::setWorldCoords( QgsPoint p )
+double QgsGCPCanvasItem::residualToScreenFactor() const
 {
-  mWorldCoords = p;
-}
+  if ( !mMapCanvas )
+  {
+    return 1;
+  }
 
-void QgsGCPCanvasItem::setId( int id )
-{
-  mId = id;
-  update();
+  double mapUnitsPerScreenPixel = mMapCanvas->mapUnitsPerPixel();
+  double mapUnitsPerRasterPixel = 1.0;
+
+  if ( mMapCanvas->mapRenderer() )
+  {
+    QStringList canvasLayers = mMapCanvas->mapRenderer()->layerSet();
+    if ( canvasLayers.size() > 0 )
+    {
+      QString layerId = canvasLayers.at( 0 );
+      QgsMapLayer* mapLayer = QgsMapLayerRegistry::instance()->mapLayer( layerId );
+      if ( mapLayer )
+      {
+        QgsRasterLayer* rasterLayer = dynamic_cast<QgsRasterLayer*>( mapLayer );
+        if ( rasterLayer )
+        {
+          mapUnitsPerRasterPixel = rasterLayer->rasterUnitsPerPixel();
+        }
+      }
+    }
+  }
+
+  return 1.0 / ( mapUnitsPerScreenPixel * mapUnitsPerRasterPixel );
 }
 
-void QgsGCPCanvasItem::updatePosition()
+void QgsGCPCanvasItem::checkBoundingRectChange()
 {
-  setPos( toCanvasCoordinates( mIsGCPSource ? mRasterCoords : mWorldCoords ) );
+  prepareGeometryChange();
 }
Index: src/plugins/georeferencer/qgsgcpcanvasitem.h
===================================================================
--- src/plugins/georeferencer/qgsgcpcanvasitem.h	(revision 13226)
+++ src/plugins/georeferencer/qgsgcpcanvasitem.h	(working copy)
@@ -20,11 +20,12 @@
 #include "qgsmapcanvas.h"
 #include "qgsmapcanvasitem.h"
 
+class QgsGeorefDataPoint;
+
 class QgsGCPCanvasItem : public QgsMapCanvasItem
 {
   public:
-    QgsGCPCanvasItem( QgsMapCanvas* mapCanvas, const QgsPoint& rasterCoords,
-                      const QgsPoint& worldCoords, bool isGCPSource/* = true*/ );
+    QgsGCPCanvasItem( QgsMapCanvas* mapCanvas, const QgsGeorefDataPoint* dataPoint, bool isGCPSource/* = true*/ );
 
     //! draws point information
     void paint( QPainter* p );
@@ -34,26 +35,23 @@
 
     QPainterPath shape() const;
 
-    void setEnabled( bool enabled );
-
-    void setRasterCoords( QgsPoint p );
-    void setWorldCoords( QgsPoint p );
-
-    int id() { return mId; }
-    void setId( int id );
-
     void updatePosition();
 
+    /**Calls prepareGeometryChange()*/
+    void checkBoundingRectChange();
+
   private:
+
+    const QgsGeorefDataPoint* mDataPoint;
     QSizeF mTextBounds;
     QBrush mPointBrush;
     QBrush mLabelBrush;
-    QgsPoint mRasterCoords;
-    QgsPoint mWorldCoords;
-
-    int mId;
     bool mIsGCPSource;
-    bool mEnabled;
+    QPen mResidualPen;
+
+    void drawResidualArrow( QPainter* p );
+    /**Calculates scale factor for residual display*/
+    double residualToScreenFactor() const;
 };
 
 #endif // QGSGCPCANVASITEM_H
Index: src/plugins/georeferencer/qgsgeorefdatapoint.h
===================================================================
--- src/plugins/georeferencer/qgsgeorefdatapoint.h	(revision 13226)
+++ src/plugins/georeferencer/qgsgeorefdatapoint.h	(working copy)
@@ -39,7 +39,7 @@
     bool isEnabled() const { return mEnabled; };
     void setEnabled( bool enabled );
 
-    int id() { return mId; }
+    int id() const { return mId; }
     void setId( int id );
 
     bool contains( const QPoint &p );
@@ -47,6 +47,9 @@
     QgsMapCanvas *srcCanvas() const { return mSrcCanvas; }
     QgsMapCanvas *dstCanvas() const { return mDstCanvas; }
 
+    QPointF residual() const { return mResidual; }
+    void setResidual( const QPointF& r );
+
   public slots:
     void moveTo( const QPoint & );
     void updateCoords();
@@ -61,4 +64,5 @@
 
     int mId;
     bool mEnabled;
+    QPointF mResidual;
 };
Index: src/plugins/georeferencer/qgsgeorefdatapoint.cpp
===================================================================
--- src/plugins/georeferencer/qgsgeorefdatapoint.cpp	(revision 13226)
+++ src/plugins/georeferencer/qgsgeorefdatapoint.cpp	(working copy)
@@ -30,8 +30,8 @@
     , mId( -1 )
     , mEnabled( enable )
 {
-  mGCPSourceItem = new QgsGCPCanvasItem( srcCanvas, pixelCoords, mapCoords, true );
-  mGCPDestinationItem = new QgsGCPCanvasItem( dstCanvas, pixelCoords, mapCoords, false );
+  mGCPSourceItem = new QgsGCPCanvasItem( srcCanvas, this, true );
+  mGCPDestinationItem = new QgsGCPCanvasItem( dstCanvas, this, false );
 
   mGCPSourceItem->setEnabled( enable );
   mGCPDestinationItem->setEnabled( enable );
@@ -58,36 +58,66 @@
 void QgsGeorefDataPoint::setPixelCoords( const QgsPoint &p )
 {
   mPixelCoords = p;
-  mGCPSourceItem->setRasterCoords( p );
-  mGCPDestinationItem->setRasterCoords( p );
+  mGCPSourceItem->update();
+  mGCPDestinationItem->update();
 }
 
 void QgsGeorefDataPoint::setMapCoords( const QgsPoint &p )
 {
   mMapCoords = p;
-  mGCPSourceItem->setWorldCoords( p );
-  mGCPDestinationItem->setWorldCoords( p );
+  if ( mGCPSourceItem )
+  {
+    mGCPSourceItem->update();
+  }
+  if ( mGCPDestinationItem )
+  {
+    mGCPDestinationItem->update();
+  }
 }
 
 void QgsGeorefDataPoint::setEnabled( bool enabled )
 {
-  mGCPSourceItem->setEnabled( enabled );
   mEnabled = enabled;
+  if ( mGCPSourceItem )
+  {
+    mGCPSourceItem->update();
+  }
 }
 
 void QgsGeorefDataPoint::setId( int id )
 {
   mId = id;
-  mGCPSourceItem->setId( id );
-  mGCPDestinationItem->setId( id );
+  if ( mGCPSourceItem )
+  {
+    mGCPSourceItem->update();
+  }
+  if ( mGCPDestinationItem )
+  {
+    mGCPDestinationItem->update();
+  }
 }
 
+void QgsGeorefDataPoint::setResidual( const QPointF& r )
+{
+  mResidual = r;
+  if ( mGCPSourceItem )
+  {
+    mGCPSourceItem->checkBoundingRectChange();
+  }
+}
+
 void QgsGeorefDataPoint::updateCoords()
 {
-  mGCPSourceItem->updatePosition();
-  mGCPDestinationItem->updatePosition();
-  mGCPSourceItem->update();
-  mGCPDestinationItem->update();
+  if ( mGCPSourceItem )
+  {
+    mGCPSourceItem->updatePosition();
+    mGCPSourceItem->update();
+  }
+  if ( mGCPDestinationItem )
+  {
+    mGCPDestinationItem->updatePosition();
+    mGCPDestinationItem->update();
+  }
 }
 
 bool QgsGeorefDataPoint::contains( const QPoint &p )
Index: src/plugins/georeferencer/qgsgcplistmodel.cpp
===================================================================
--- src/plugins/georeferencer/qgsgcplistmodel.cpp	(revision 13226)
+++ src/plugins/georeferencer/qgsgcplistmodel.cpp	(working copy)
@@ -143,6 +143,12 @@
     {
       dX = dY = residual = 0;
     }
+
+    if ( p )
+    {
+      p->setResidual( QPointF( dX, dY ) );
+    }
+
     if ( residual >= 0.f )
     {
       setItem( i, j++, QGSSTANDARDITEM( dX ) /*create_item<double>(dX)*/ );