Index: imageplugins/perspective/perspectivewidget.h
===================================================================
--- imageplugins/perspective/perspectivewidget.h	(Revision 925640)
+++ imageplugins/perspective/perspectivewidget.h	(Arbeitskopie)
@@ -85,6 +85,7 @@
 
     void slotChangeGuideColor(const QColor &color);
     void slotChangeGuideSize(int size);
+    void slotInverseTransformationChanged(bool isEnabled);
 
 signals:
 
@@ -126,6 +127,7 @@
     bool                 m_antiAlias;
     bool                 m_drawWhileMoving;
     bool                 m_drawGrid;
+    bool                 m_inverseTransformation;
 
     uint                *m_data;
     int                  m_w;
Index: imageplugins/perspective/perspectivetool.cpp
===================================================================
--- imageplugins/perspective/perspectivetool.cpp	(Revision 925640)
+++ imageplugins/perspective/perspectivetool.cpp	(Arbeitskopie)
@@ -125,6 +125,7 @@
     KSeparator *line2         = new KSeparator (Qt::Horizontal, m_gboxSettings->plainPage());
     m_drawWhileMovingCheckBox = new QCheckBox(i18n("Draw preview while moving"), m_gboxSettings->plainPage());
     m_drawGridCheckBox        = new QCheckBox(i18n("Draw grid"), m_gboxSettings->plainPage());
+    m_inverseTransformation   = new QCheckBox(i18n("Inverse transformation"), m_gboxSettings->plainPage());
 
     // -------------------------------------------------------------
 
@@ -160,13 +161,14 @@
     gridLayout->addWidget(line2,                        8, 0, 1, 3);
     gridLayout->addWidget(m_drawWhileMovingCheckBox,    9, 0, 1, 3);
     gridLayout->addWidget(m_drawGridCheckBox,          10, 0, 1, 3);
-    gridLayout->addWidget(label7,                      11, 0, 1, 1);
-    gridLayout->addWidget(m_guideColorBt,              11, 2, 1, 1);
-    gridLayout->addWidget(space,                       12, 0, 1, 3);
-    gridLayout->addWidget(label8,                      13, 0, 1, 1);
-    gridLayout->addWidget(m_guideSize,                 13, 2, 1, 1);
+    gridLayout->addWidget(m_inverseTransformation,     11, 0, 1, 3);
+    gridLayout->addWidget(label7,                      12, 0, 1, 1);
+    gridLayout->addWidget(m_guideColorBt,              12, 2, 1, 1);
+    gridLayout->addWidget(space,                       13, 0, 1, 3);
+    gridLayout->addWidget(label8,                      14, 0, 1, 1);
+    gridLayout->addWidget(m_guideSize,                 14, 2, 1, 1);
     gridLayout->setColumnStretch(1, 10);
-    gridLayout->setRowStretch(14, 10);
+    gridLayout->setRowStretch(15, 10);
 
     setToolSettings(m_gboxSettings);
     init();
@@ -187,6 +189,7 @@
 
     connect(m_guideSize, SIGNAL(valueChanged(int)),
             m_previewWidget, SLOT(slotChangeGuideSize(int)));
+    connect(m_inverseTransformation, SIGNAL(toggled(bool)), m_previewWidget, SLOT(slotInverseTransformationChanged(bool)));
 }
 
 PerspectiveTool::~PerspectiveTool()
@@ -202,6 +205,7 @@
     m_drawGridCheckBox->setChecked(group.readEntry("Draw Grid", false));
     m_guideColorBt->setColor(group.readEntry("Guide Color", defaultGuideColor));
     m_guideSize->setValue(group.readEntry("Guide Width", 1));
+    m_inverseTransformation->setChecked(group.readEntry("Inverse Transformation", false));
     m_previewWidget->slotToggleDrawWhileMoving(m_drawWhileMovingCheckBox->isChecked());
     m_previewWidget->slotToggleDrawGrid(m_drawGridCheckBox->isChecked());
     m_previewWidget->slotChangeGuideColor(m_guideColorBt->color());
@@ -216,6 +220,7 @@
     group.writeEntry("Draw Grid", m_drawGridCheckBox->isChecked());
     group.writeEntry("Guide Color", m_guideColorBt->color());
     group.writeEntry("Guide Width", m_guideSize->value());
+    group.writeEntry("Inverse Transformation", m_inverseTransformation->isChecked());
     config->sync();
 }
 
Index: imageplugins/perspective/perspectivetool.h
===================================================================
--- imageplugins/perspective/perspectivetool.h	(Revision 925640)
+++ imageplugins/perspective/perspectivetool.h	(Arbeitskopie)
@@ -80,6 +80,7 @@
 
     QCheckBox                   *m_drawWhileMovingCheckBox;
     QCheckBox                   *m_drawGridCheckBox;
+    QCheckBox                   *m_inverseTransformation;
 
     QSpinBox                    *m_guideSize;
 
Index: imageplugins/perspective/perspectivewidget.cpp
===================================================================
--- imageplugins/perspective/perspectivewidget.cpp	(Revision 925640)
+++ imageplugins/perspective/perspectivewidget.cpp	(Arbeitskopie)
@@ -73,6 +73,7 @@
 
     m_drawGrid        = false;
     m_drawWhileMoving = true;
+    m_inverseTransformation = false;
     m_currentResizing = ResizingNone;
     m_guideColor      = Qt::red;
     m_guideSize       = 1;
@@ -210,6 +211,12 @@
                               targetImg.bits(), targetImg.width(), targetImg.height());
 }
 
+void PerspectiveWidget::slotInverseTransformationChanged(bool isEnabled) {
+    m_inverseTransformation = isEnabled;
+    updatePixmap();
+    repaint();
+}
+
 void PerspectiveWidget::slotToggleAntiAliasing(bool a)
 {
     m_antiAlias = a;
@@ -276,8 +283,17 @@
 
     m_pixmap->fill(palette().color(QPalette::Background));
 
+    if(m_inverseTransformation) {
+        m_transformedCenter = buildPerspective(QPoint(0, 0), QPoint(m_w, m_h),
+                                               m_topLeftPoint, m_topRightPoint,
+                                               m_bottomLeftPoint, m_bottomRightPoint);
+      
+	m_iface->putPreviewImage(m_previewImage.bits());
+        m_iface->paint(m_pixmap, m_rect.x(), m_rect.y(),
+                       m_rect.width(), m_rect.height());
     // if we are resizing with the mouse, compute and draw only if drawWhileMoving is set
-    if (m_currentResizing == ResizingNone || m_drawWhileMoving)
+    }
+    else if ((m_currentResizing == ResizingNone || m_drawWhileMoving))
     {
         // Create preview image
 
@@ -456,9 +472,22 @@
     transform.scale    (scalex, scaley);
     transform.multiply (matrix);
 
-    // Compute perspective transformation to image if image data containers exist.
-    if (orgImage && destImage)
+    if(orgImage && destImage) {
+      if(m_inverseTransformation) {
+	Matrix inverseTransform = transform;
+	inverseTransform.invert();
+	
+	//Transform the matrix so it puts the result into the getTargetSize() rectangle
+	Matrix transformIntoBounds;
+	transformIntoBounds.scale(double(getTargetSize().width()) / double(orgImage->width()), double(getTargetSize().height()) / double(orgImage->height()));
+	transformIntoBounds.translate(getTargetSize().left(), getTargetSize().top());
+	inverseTransform.multiply(transformIntoBounds);
+        transformAffine(orgImage, destImage, inverseTransform, background);
+      }else{
+	// Compute perspective transformation to image if image data containers exist.
         transformAffine(orgImage, destImage, transform, background);
+      }
+    }
 
     // Calculate the grid array points.
     double newX, newY;
@@ -757,7 +786,7 @@
                                         m_w-1, 0 );
                 QRegion unsableArea(unsablePoints);
 
-                if ( unsableArea.contains(pm) ) return;
+                if ( unsableArea.contains(pm) && !m_inverseTransformation ) return;
 
                 m_topLeftPoint = pm - m_rect.topLeft();
                 setCursor( Qt::SizeFDiagCursor );
@@ -775,7 +804,7 @@
                                         m_w-1, m_h-1);
                 QRegion unsableArea(unsablePoints);
 
-                if ( unsableArea.contains(pm) ) return;
+                if ( unsableArea.contains(pm) && !m_inverseTransformation ) return;
 
                 m_topRightPoint = pm - m_rect.topLeft();
                 setCursor( Qt::SizeBDiagCursor );
@@ -793,7 +822,7 @@
                                         0, 0);
                 QRegion unsableArea(unsablePoints);
 
-                if ( unsableArea.contains(pm) ) return;
+                if ( unsableArea.contains(pm) && !m_inverseTransformation ) return;
 
                 m_bottomLeftPoint = pm - m_rect.topLeft();
                 setCursor( Qt::SizeBDiagCursor );
@@ -811,7 +840,7 @@
                                         0, m_w-1);
                 QRegion unsableArea(unsablePoints);
 
-                if ( unsableArea.contains(pm) ) return;
+                if ( unsableArea.contains(pm) && !m_inverseTransformation ) return;
 
                 m_bottomRightPoint = pm - m_rect.topLeft();
                 setCursor( Qt::SizeFDiagCursor );