diff --git a/link.png b/link.png
new file mode 100644
index 0000000..b11d3ba
Binary files /dev/null and b/link.png differ
diff --git a/resources.qrc b/resources.qrc
index a2e2a7b..b71d1ce 100644
--- a/resources.qrc
+++ b/resources.qrc
@@ -18,6 +18,7 @@
         <file>shaders/debayer.frag</file>
         <file>shaders/debayer.vert</file>
         <file>falsecolor.png</file>
+        <file>link.png</file>
     </qresource>
     <qresource prefix="/" lang="en">
         <file alias="help">about/help_en</file>
diff --git a/stretchtoolbar.cpp b/stretchtoolbar.cpp
index b4ee306..ade2411 100644
--- a/stretchtoolbar.cpp
+++ b/stretchtoolbar.cpp
@@ -23,7 +23,7 @@ StretchToolbar::StretchToolbar(QWidget *parent) : QToolBar(tr("Stretch toolbar")
     m_stfSlider = new STFSlider(Qt::white, this);
     vbox1->addWidget(m_stfSlider);
 
-    /*m_stfSliderR = new STFSlider(Qt::red, this);
+    m_stfSliderR = new STFSlider(Qt::red, this);
     m_stfSliderG = new STFSlider(Qt::green, this);
     m_stfSliderB = new STFSlider(Qt::blue, this);
     QWidget *rgb = new QWidget(this);
@@ -31,12 +31,12 @@ StretchToolbar::StretchToolbar(QWidget *parent) : QToolBar(tr("Stretch toolbar")
     vbox2->setSpacing(0);
     vbox2->addWidget(m_stfSliderR);
     vbox2->addWidget(m_stfSliderG);
-    vbox2->addWidget(m_stfSliderB);*/
+    vbox2->addWidget(m_stfSliderB);
 
     m_stack = new QStackedWidget(this);
     m_stack->addWidget(lum);
-    //m_stack->addWidget(rgb);
-    //m_stack->setCurrentIndex(0);
+    m_stack->addWidget(rgb);
+    m_stack->setCurrentIndex(0);
     addWidget(m_stack);
 
     connect(m_stfSlider, &STFSlider::paramChanged, [this](float blackPoint, float midPoint, float whitePoint){
@@ -45,7 +45,7 @@ StretchToolbar::StretchToolbar(QWidget *parent) : QToolBar(tr("Stretch toolbar")
         m_mtfParam.whitePoint[0] = m_mtfParam.whitePoint[1] = m_mtfParam.whitePoint[2] = whitePoint;
         emit paramChanged(m_mtfParam);
     });
-    /*connect(m_stfSliderR, &STFSlider::paramChanged, [this](float blackPoint, float midPoint, float whitePoint){
+    connect(m_stfSliderR, &STFSlider::paramChanged, [this](float blackPoint, float midPoint, float whitePoint){
         m_mtfParam.blackPoint[0] = blackPoint;
         m_mtfParam.midPoint[0] = midPoint;
         m_mtfParam.whitePoint[0] = whitePoint;
@@ -62,7 +62,11 @@ StretchToolbar::StretchToolbar(QWidget *parent) : QToolBar(tr("Stretch toolbar")
         m_mtfParam.midPoint[2] = midPoint;
         m_mtfParam.whitePoint[2] = whitePoint;
         emit paramChanged(m_mtfParam);
-    });*/
+    });
+
+    QAction *rgbStretch = addAction(QIcon(":/link.png"), tr("Linked stretch"));
+    rgbStretch->setCheckable(true);
+    connect(rgbStretch, &QAction::toggled, this, &StretchToolbar::unlinkStretch);
 
     QAction *autoStretchButton = addAction(QIcon(":/nuke.png"), tr("Auto Stretch F12"));
     autoStretchButton->setShortcut(Qt::Key_F12);
@@ -74,15 +78,15 @@ StretchToolbar::StretchToolbar(QWidget *parent) : QToolBar(tr("Stretch toolbar")
 
     QAction *invertButton = addAction(QIcon(":/invert.png"), tr("Invert colors"));
     invertButton->setCheckable(true);
-    connect(invertButton, SIGNAL(toggled(bool)), this, SIGNAL(invert(bool)));
+    connect(invertButton, &QAction::toggled, this, &StretchToolbar::invert);
 
     QAction *falseColorButton = addAction(QIcon(":/falsecolor.png"), tr("False color"));
     falseColorButton->setCheckable(true);
-    connect(falseColorButton, SIGNAL(toggled(bool)), this, SIGNAL(falseColor(bool)));
+    connect(falseColorButton, &QAction::toggled, this, &StretchToolbar::falseColor);
 
     QAction *superPixelButton = addAction(QIcon(":/bayer.png"), tr("Debayer CFA"));
     superPixelButton->setCheckable(true);
-    connect(superPixelButton, SIGNAL(toggled(bool)), this, SIGNAL(superPixel(bool)));
+    connect(superPixelButton, &QAction::toggled, this, &StretchToolbar::superPixel);
 
     m_autoStretchOnLoad = addAction(QIcon(":/nuke_a.png"), tr("Apply auto stretch on load"));
     m_autoStretchOnLoad->setCheckable(true);
@@ -90,49 +94,52 @@ StretchToolbar::StretchToolbar(QWidget *parent) : QToolBar(tr("Stretch toolbar")
 
 void StretchToolbar::stretchImage(Image *img)
 {
-    if(img)
+    if(img && img->rawImage())
     {
-        if(img->rawImage())
+        const RawImage::Stats &stats = img->rawImage()->imageStats();
+        int ch = img->rawImage()->channels() == 1 ? 1 : 3;
+        float bp2 = 0;
+        float mid2 = 0;
+        float max2 = 0;
+        for(int i=0; i < ch; i++)
         {
-            const RawImage::Stats &stats = img->rawImage()->imageStats();
-            int ch = img->rawImage()->channels() == 1 ? 1 : 3;
-            float bp2 = 0;
-            float mid2 = 0;
-            float max2 = 0;
-            for(int i=0; i < ch; i++)
-            {
-                double median, mad, max;
-                median = stats.m_median[i];
-                mad = stats.m_mad[i];
-                max = stats.m_max[i];
-                median /= img->rawImage()->norm();
-                mad /= img->rawImage()->norm();
-                max /= img->rawImage()->norm();
-                if(max>1.0f)max = 1.0f;
-                float bp = median + mad * BLACK_POINT_SIGMA * MAD_TO_SIGMA;
-                float mid = MTF(median - bp, TARGET_BACKGROUND);
-                m_mtfParam.blackPoint[i] = bp;
-                m_mtfParam.midPoint[i] = mid;
-                m_mtfParam.whitePoint[i] = max;
-                bp2 += bp;
-                mid2 += mid;
-                max2 += max;
-            }
-            if(m_stack->currentIndex() == 0)
-            {
-                m_mtfParam.blackPoint[0] = m_mtfParam.blackPoint[1] = m_mtfParam.blackPoint[2] = bp2 / ch;
-                m_mtfParam.midPoint[0] = m_mtfParam.midPoint[1] = m_mtfParam.midPoint[2] = mid2 / ch;
-                m_mtfParam.whitePoint[0] = m_mtfParam.whitePoint[1] = m_mtfParam.whitePoint[2] = max2 / ch;
-                m_stfSlider->setMTFParams(m_mtfParam.blackPoint[0], m_mtfParam.midPoint[0], m_mtfParam.whitePoint[0]);
-            }
-            else
-            {
-                m_stfSliderR->setMTFParams(m_mtfParam.blackPoint[0], m_mtfParam.midPoint[0], m_mtfParam.whitePoint[0]);
-                m_stfSliderG->setMTFParams(m_mtfParam.blackPoint[1], m_mtfParam.midPoint[1], m_mtfParam.whitePoint[1]);
-                m_stfSliderB->setMTFParams(m_mtfParam.blackPoint[2], m_mtfParam.midPoint[2], m_mtfParam.whitePoint[2]);
-            }
-            emit paramChanged(m_mtfParam);
+            double median, mad, max;
+            median = stats.m_median[i];
+            mad = stats.m_mad[i];
+            max = stats.m_max[i];
+            median /= img->rawImage()->norm();
+            mad /= img->rawImage()->norm();
+            max /= img->rawImage()->norm();
+            if(max>1.0f)max = 1.0f;
+            float bp = median + mad * BLACK_POINT_SIGMA * MAD_TO_SIGMA;
+            float mid = MTF(median - bp, TARGET_BACKGROUND);
+            m_mtfParam.blackPoint[i] = bp;
+            m_mtfParam.midPoint[i] = mid;
+            m_mtfParam.whitePoint[i] = max;
+            bp2 += bp;
+            mid2 += mid;
+            max2 += max;
         }
+        if(ch == 1)
+        {
+            m_mtfParam.blackPoint[1] = m_mtfParam.blackPoint[2] = m_mtfParam.blackPoint[0];
+            m_mtfParam.midPoint[1] = m_mtfParam.midPoint[2] = m_mtfParam.midPoint[0];
+            m_mtfParam.whitePoint[1] = m_mtfParam.whitePoint[2] = m_mtfParam.whitePoint[0];
+        }
+        if(m_stack->currentIndex() == 0)
+        {
+            m_mtfParam.blackPoint[0] = m_mtfParam.blackPoint[1] = m_mtfParam.blackPoint[2] = bp2 / ch;
+            m_mtfParam.midPoint[0] = m_mtfParam.midPoint[1] = m_mtfParam.midPoint[2] = mid2 / ch;
+            m_mtfParam.whitePoint[0] = m_mtfParam.whitePoint[1] = m_mtfParam.whitePoint[2] = max2 / ch;
+            m_stfSlider->setMTFParams(m_mtfParam.blackPoint[0], m_mtfParam.midPoint[0], m_mtfParam.whitePoint[0]);
+        }
+        else
+        {
+            m_stfSliderR->setMTFParams(m_mtfParam.blackPoint[0], m_mtfParam.midPoint[0], m_mtfParam.whitePoint[0]);
+            m_stfSliderG->setMTFParams(m_mtfParam.blackPoint[1], m_mtfParam.midPoint[1], m_mtfParam.whitePoint[1]);
+            m_stfSliderB->setMTFParams(m_mtfParam.blackPoint[2], m_mtfParam.midPoint[2], m_mtfParam.whitePoint[2]);
+        }
+        emit paramChanged(m_mtfParam);
     }
 }
 
@@ -140,10 +147,16 @@ void StretchToolbar::resetMTF()
 {
     MTFParam params;
     m_mtfParam = params;
-    m_stfSlider->setMTFParams(0, 0.5, 1);
-    m_stfSliderR->setMTFParams(0, 0.5, 1);
-    m_stfSliderG->setMTFParams(0, 0.5, 1);
-    m_stfSliderB->setMTFParams(0, 0.5, 1);
+    if(m_stack->currentIndex() == 0)
+    {
+        m_stfSlider->setMTFParams(0, 0.5, 1);
+    }
+    else
+    {
+        m_stfSliderR->setMTFParams(0, 0.5, 1);
+        m_stfSliderG->setMTFParams(0, 0.5, 1);
+        m_stfSliderB->setMTFParams(0, 0.5, 1);
+    }
     emit paramChanged(params);
 }
 
@@ -152,3 +165,22 @@ void StretchToolbar::imageLoaded(Image *img)
     if(m_autoStretchOnLoad->isChecked())
         stretchImage(img);
 }
+
+void StretchToolbar::unlinkStretch(bool enable)
+{
+    if(enable)
+    {
+        m_stack->setCurrentIndex(1);
+        m_mtfParam.blackPoint[0] = m_stfSliderR->blackPoint(); m_mtfParam.midPoint[0] = m_stfSliderR->midPoint(); m_mtfParam.whitePoint[0] = m_stfSliderR->whitePoint();
+        m_mtfParam.blackPoint[1] = m_stfSliderG->blackPoint(); m_mtfParam.midPoint[1] = m_stfSliderG->midPoint(); m_mtfParam.whitePoint[1] = m_stfSliderG->whitePoint();
+        m_mtfParam.blackPoint[2] = m_stfSliderB->blackPoint(); m_mtfParam.midPoint[2] = m_stfSliderB->midPoint(); m_mtfParam.whitePoint[2] = m_stfSliderB->whitePoint();
+    }
+    else
+    {
+        m_stack->setCurrentIndex(0);
+        m_mtfParam.blackPoint[0] = m_mtfParam.blackPoint[1] = m_mtfParam.blackPoint[2] = m_stfSlider->blackPoint();
+        m_mtfParam.midPoint[0] = m_mtfParam.midPoint[1] = m_mtfParam.midPoint[2] = m_stfSlider->midPoint();
+        m_mtfParam.whitePoint[0] = m_mtfParam.whitePoint[1] = m_mtfParam.whitePoint[2] = m_mtfParam.whitePoint[2] = m_stfSlider->whitePoint();
+    }
+    emit paramChanged(m_mtfParam);
+}
diff --git a/stretchtoolbar.h b/stretchtoolbar.h
index 3ec895d..8b35b9d 100644
--- a/stretchtoolbar.h
+++ b/stretchtoolbar.h
@@ -30,6 +30,7 @@ public slots:
     void stretchImage(Image *img);
     void resetMTF();
     void imageLoaded(Image *img);
+    void unlinkStretch(bool enable);
 signals:
     void paramChanged(const MTFParam &params);
     void autoStretch();