diff --git a/modules/core/src/image/vpImageCircle.cpp b/modules/core/src/image/vpImageCircle.cpp
index 25dfdd12b2..4a7c4c6bcc 100644
--- a/modules/core/src/image/vpImageCircle.cpp
+++ b/modules/core/src/image/vpImageCircle.cpp
@@ -481,7 +481,7 @@ void computeIntersectionsTopLeftBottom(const float &u_c, const float &v_c, const
   std::pair<float, float> crossing_theta_u_min, crossing_theta_u_max;
   std::pair<float, float> crossing_theta_v_min, crossing_theta_v_max;
   float crossing_u_top = vmin_roi; // We cross the u-axis of the top axis of the RoI at the minimum v-coordinate of the RoI
-  float crossing_v = vmin_roi; // We cross the v-axis of the RoI at the minimum u-coordinate of the RoI
+  float crossing_v = umin_roi; // We cross the v-axis of the RoI at the minimum u-coordinate of the RoI
   computePerpendicularAxesIntersections(u_c, v_c, radius, crossing_u_top, crossing_v,
                                         crossing_theta_u_min, crossing_theta_u_max,
                                         crossing_theta_v_min, crossing_theta_v_max);
@@ -501,25 +501,63 @@ void computeIntersectionsTopLeftBottom(const float &u_c, const float &v_c, const
   float theta_u_max_bottom = crossing_theta_u_max.first;
   float u_umin_bottom = crossing_theta_u_min.second;
   float u_umax_bottom = crossing_theta_u_max.second;
+  int cas = -1;
   if (u_umin_top >= umin_roi && u_umin_bottom >= umin_roi && v_vmin >= vmin_roi && v_vmax <= vmax_roi) {
     // case intersection top + left + bottom twice
     delta_theta = (theta_v_min - theta_u_min_top) + (theta_u_max_top - theta_u_max_bottom) + (theta_u_min_bottom - theta_v_max);
+    cas = 0;
   }
   else if (u_umin_top <= umin_roi && v_vmin <= vmin_roi && u_umin_bottom <= umin_roi && v_vmax >= vmax_roi) {
     // case intersection top and bottom
     delta_theta = (theta_u_max_top - theta_u_max_bottom);
+    cas = 1;
   }
   else if (u_umax_top <= umin_roi && u_umax_bottom <= umin_roi && v_vmin >= vmin_roi && v_vmax <= vmax_roi) {
     // case left only
     computeIntersectionsLeftBorderOnly(u_c, umin_roi, radius, delta_theta);
+    cas = 2;
   }
   else if (u_umax_bottom > umin_roi && v_vmin >= vmin_roi) {
     // case bottom/left corner
     computeIntersectionsBottomLeft(u_c, v_c, umin_roi, vmax_roi, radius, delta_theta);
+    cas = 3;
   }
   else if (u_umax_top > umin_roi && v_vmax <= vmax_roi) {
     // case top/left corner
     computeIntersectionsTopLeft(u_c, v_c, umin_roi, vmin_roi, radius, delta_theta);
+    cas = 4;
+  }
+
+  if (delta_theta < 0.f) {
+    std::cout << "--- computeIntersectionsTopLeftBottom with negative result ---" << std::endl;
+    std::cout << "\tu_umin_top = " << u_umin_top << "\tu_umax_top = " << u_umax_top << std::endl;
+    std::cout << "\tu_umin_bot = " << u_umin_bottom << "\tu_umax_bot = " << u_umax_bottom << std::endl;
+    std::cout << "\tv_vmin = " << v_vmin << "\tv_vmax = " << v_vmax << std::endl;
+    std::cout << "\ttheta_u_min_top = " << theta_u_min_top << "\ttheta_u_max_top = " << theta_u_max_top << std::endl;
+    std::cout << "\ttheta_u_min_bot = " << theta_u_min_bottom << "\ttheta_u_max_bot = " << theta_u_max_bottom << std::endl;
+    std::cout << "\ttheta_v_min = " << theta_v_min << "\ttheta_v_max = " << theta_v_max << std::endl;
+    std::cout << "\tcas = ";
+    std::string nameCase;
+    switch (cas) {
+    case 0:
+      nameCase = "top + left + bottom twice";
+      break;
+    case 1:
+      nameCase = "top and bottom";
+      break;
+    case 2:
+      nameCase = "left only";
+      break;
+    case 3:
+      nameCase = "bottom/left corner";
+      break;
+    case 4:
+      nameCase = "top/left corner";
+      break;
+    default:
+      throw (vpException(vpException::fatalError, "Uncorrect case"));
+    }
+    std::cout << nameCase << std::endl;
   }
 }