diff --git a/modules/tracker/rbt/include/visp3/rbt/vpColorHistogram.h b/modules/tracker/rbt/include/visp3/rbt/vpColorHistogram.h
index d2e1bc9668..a390b5ad0d 100644
--- a/modules/tracker/rbt/include/visp3/rbt/vpColorHistogram.h
+++ b/modules/tracker/rbt/include/visp3/rbt/vpColorHistogram.h
@@ -89,6 +89,8 @@ class VISP_EXPORT vpColorHistogram
   void merge(const vpColorHistogram &other, float alpha);
 
   void computeProbas(const vpImage<vpRGBa> &image, vpImage<float> &proba) const;
+  void computeProbas(const vpImage<vpRGBa> &image, vpImage<float> &proba, const vpRect &bb) const;
+
 
   inline unsigned int colorToIndex(const vpRGBa &p) const
   {
diff --git a/modules/tracker/rbt/include/visp3/rbt/vpColorHistogramMask.h b/modules/tracker/rbt/include/visp3/rbt/vpColorHistogramMask.h
index d431f393b4..6240c7c74b 100644
--- a/modules/tracker/rbt/include/visp3/rbt/vpColorHistogramMask.h
+++ b/modules/tracker/rbt/include/visp3/rbt/vpColorHistogramMask.h
@@ -101,6 +101,12 @@ class VISP_EXPORT vpColorHistogramMask : public vpObjectMask
     }
     m_backgroundUpdateRate = updateRate;
   }
+
+  bool isComputedOnlyOnBoundingBox() const { return m_computeOnBBOnly; }
+  void setComputeOnlyOnBoundingBox(bool bbOnly)
+  {
+    m_computeOnBBOnly = bbOnly;
+  }
   /**
    * @}
    */
@@ -116,6 +122,8 @@ class VISP_EXPORT vpColorHistogramMask : public vpObjectMask
 
   vpImage<bool> m_mask;
   vpImage<float> m_probaObject, m_probaBackground;
+
+  bool m_computeOnBBOnly;
 };
 
 END_VISP_NAMESPACE
diff --git a/modules/tracker/rbt/src/features/vpRBSilhouetteCCDTracker.cpp b/modules/tracker/rbt/src/features/vpRBSilhouetteCCDTracker.cpp
index 457792efd0..4b56e4eed1 100644
--- a/modules/tracker/rbt/src/features/vpRBSilhouetteCCDTracker.cpp
+++ b/modules/tracker/rbt/src/features/vpRBSilhouetteCCDTracker.cpp
@@ -93,7 +93,7 @@ void vpRBSilhouetteCCDTracker::extractFeatures(const vpRBFeatureTrackerInput &fr
     // std::cout << sp.j << ", " << sp.i << std::endl;
     int ii = sp.i, jj = sp.j;
 
-    if (ii <= 4 || jj <= 4 || static_cast<unsigned int>(ii) >= frame.I.getHeight() - 4 || static_cast<unsigned int>(jj) >= frame.I.getWidth() - 4) {
+    if (ii <= m_ccdParameters.h || jj <= m_ccdParameters.h || static_cast<unsigned int>(ii) >= frame.I.getHeight() - m_ccdParameters.h || static_cast<unsigned int>(jj) >= frame.I.getWidth() - m_ccdParameters.h) {
       continue;
     }
     vpRBSilhouetteControlPoint pccd;
diff --git a/modules/tracker/rbt/src/mask/vpColorHistogram.cpp b/modules/tracker/rbt/src/mask/vpColorHistogram.cpp
index db1b975647..2fe9294451 100644
--- a/modules/tracker/rbt/src/mask/vpColorHistogram.cpp
+++ b/modules/tracker/rbt/src/mask/vpColorHistogram.cpp
@@ -128,6 +128,25 @@ void vpColorHistogram::computeProbas(const vpImage<vpRGBa> &image, vpImage<float
   }
 }
 
+void vpColorHistogram::computeProbas(const vpImage<vpRGBa> &image, vpImage<float> &proba, const vpRect &bb) const
+{
+  proba.resize(image.getHeight(), image.getWidth(), 0.f);
+  const int h = static_cast<int>(image.getHeight()), w = static_cast<int>(image.getWidth());
+  const int top = static_cast<int>(bb.getTop());
+  const int left = static_cast<int>(bb.getLeft());
+  const int bottom = std::min(h- 1, static_cast<int>(bb.getBottom()));
+  const int right = std::min(w - 1, static_cast<int>(bb.getRight()));
+#pragma omp parallel for
+  for (unsigned int i = top; i <= static_cast<unsigned int>(bottom); ++i) {
+    const vpRGBa *colorRow = image[i];
+    float *probaRow = proba[i];
+    for (unsigned int j = left; j <= static_cast<unsigned int>(right); ++j) {
+      probaRow[j] = m_probas[colorToIndex(colorRow[j])];
+    }
+  }
+}
+
+
 
 double vpColorHistogram::kl(const vpColorHistogram &other) const
 {
@@ -175,16 +194,16 @@ void vpColorHistogram::computeSplitHistograms(const vpImage<vpRGBa> &image, cons
 
   std::vector<unsigned int> countsIn(bins, 0), countsOut(bins, 0);
 
-#pragma omp parallel
+//#pragma omp parallel
   {
     std::vector<unsigned int>localCountsIn(bins, 0), localCountsOut(bins, 0);
-#pragma omp for schedule(static, 1024)
+//#pragma omp for schedule(static, 1024)
     for (unsigned int i = 0; i < image.getSize(); ++i) {
       unsigned int index = insideMask.colorToIndex(image.bitmap[i]);
       localCountsIn[index] += mask.bitmap[i] > 0;
       localCountsOut[index] += mask.bitmap[i] == 0;
     }
-#pragma omp critical
+//#pragma omp critical
     {
       for (unsigned int i = 0; i < bins; ++i) {
         countsIn[i] += localCountsIn[i];
diff --git a/modules/tracker/rbt/src/mask/vpColorHistogramMask.cpp b/modules/tracker/rbt/src/mask/vpColorHistogramMask.cpp
index c83aa00acb..3b131de267 100644
--- a/modules/tracker/rbt/src/mask/vpColorHistogramMask.cpp
+++ b/modules/tracker/rbt/src/mask/vpColorHistogramMask.cpp
@@ -38,7 +38,7 @@
 
 BEGIN_VISP_NAMESPACE
 
-vpColorHistogramMask::vpColorHistogramMask() { }
+vpColorHistogramMask::vpColorHistogramMask() : m_computeOnBBOnly(false) { }
 
 void vpColorHistogramMask::updateMask(const vpRBFeatureTrackerInput &frame,
                                       const vpRBFeatureTrackerInput &previousFrame,
@@ -74,8 +74,6 @@ void vpColorHistogramMask::updateMask(const vpRBFeatureTrackerInput &frame,
   }
   vpColorHistogram::computeSplitHistograms(rgb, m_mask, renderBB, m_histObjectFrame, m_histBackgroundFrame);
 
-
-
   const float pObject = static_cast<float>(m_histObjectFrame.getNumPixels()) / static_cast<float>(m_mask.getSize());
   const float pBackground = 1.f - pObject;
   {
@@ -83,24 +81,52 @@ void vpColorHistogramMask::updateMask(const vpRBFeatureTrackerInput &frame,
       if (pObject != 0.f) {
         m_histObject.merge(m_histObjectFrame, m_objectUpdateRate);
       }
-      // m_histObject.computeProbas(frame.IRGB, m_probaObject);
+      if (m_computeOnBBOnly) {
+        m_histObject.computeProbas(frame.IRGB, m_probaObject, frame.renders.boundingBox);
+      }
+      else {
+        m_histObject.computeProbas(frame.IRGB, m_probaObject);
+      }
     }
     {
       if (pBackground != 0.f) {
         m_histBackground.merge(m_histBackgroundFrame, m_backgroundUpdateRate);
       }
-      // m_histBackground.computeProbas(frame.IRGB, m_probaBackground);
+      if (m_computeOnBBOnly) {
+        m_histBackground.computeProbas(frame.IRGB, m_probaBackground, frame.renders.boundingBox);
+      }
+      else {
+        m_histBackground.computeProbas(frame.IRGB, m_probaBackground);
+      }
     }
   }
 
-  mask.resize(height, width);
+  if (m_computeOnBBOnly) {
+    mask.resize(height, width, 0.f);
 #pragma omp parallel for
-  for (unsigned int i = 0; i < mask.getSize(); ++i) {
-    float poPix = m_histObject.probability(frame.IRGB.bitmap[i]);
-    float pbPix = m_histBackground.probability(frame.IRGB.bitmap[i]);
+    for (unsigned int i = top; i <= static_cast<unsigned int>(bottom); ++i) {
+      for (unsigned int j = left; j <= static_cast<unsigned int>(right); ++j) {
+        const float poPix = m_probaObject[i][j];
+        const float pbPix = m_probaBackground[i][j];
+
+        float denom = (pObject * poPix + pBackground * pbPix);
+        mask[i][j] = (denom > 0.f) * std::max(0.f, std::min(1.f, (poPix / denom)));
+        m_mask[i][j] = renderDepth[i][j] > 0.f && fabs(renderDepth[i][j] - depth[i][j]) <= m_depthErrorTolerance;
+      }
+    }
+  }
+  else {
+    mask.resize(height, width);
+    for (unsigned int i = 0; i < mask.getSize(); ++i) {
+      // float poPix = m_histObject.probability(frame.IRGB.bitmap[i]);
+      // float pbPix = m_histBackground.probability(frame.IRGB.bitmap[i]);
+      const float poPix = m_probaObject.bitmap[i];
+      const float pbPix = m_probaBackground.bitmap[i];
+
+      float denom = (pObject * poPix + pBackground * pbPix);
+      mask.bitmap[i] = (denom > 0.f) * std::max(0.f, std::min(1.f, (poPix / denom)));
+    }
 
-    float denom = (pObject * poPix + pBackground * pbPix);
-    mask.bitmap[i] = (denom > 0.f) * std::max(0.f, std::min(1.f, (poPix / denom)));
   }
 
 }
@@ -112,6 +138,7 @@ void vpColorHistogramMask::loadJsonConfiguration(const nlohmann::json &json)
   m_backgroundUpdateRate = json.at("backgroundUpdateRate");
   m_objectUpdateRate = json.at("objectUpdateRate");
   m_depthErrorTolerance = json.at("maxDepthError");
+  m_computeOnBBOnly = json.value("computeOnlyOnBoundingBox", m_computeOnBBOnly);
 }
 #endif