Merge remote-tracking branch 'upstream/3.4' into merge-3.4

modules/aruco/src/apriltag_quad_thresh.cpp

@@ -935,8 +935,8 @@ int fit_quad(const Ptr<DetectorParameters> &_params, const Mat im, zarray_t *clu
                 double x = lines[i1][0] - L1*A01;
                 double y = lines[i1][1] - L1*A11;
 
-                CV_Assert(fabs(x - quad->p[i][0]) < 0.001,
-                        fabs(y - quad->p[i][1]) < 0.001);
+                CV_Assert(fabs(x - quad->p[i][0]) < 0.001);
+                CV_Assert(fabs(y - quad->p[i][1]) < 0.001);
             }
 #endif // NDEBUG
 

modules/ovis/src/meshes.cpp

@@ -38,10 +38,10 @@ void createPointCloudMesh(const String& name, InputArray vertices, InputArray co
 {
     int color_type = colors.type();
     CV_Assert(_app);
-    CV_CheckTypeEQ(vertices.type(), CV_32FC3, "")
+    CV_CheckTypeEQ(vertices.type(), CV_32FC3, "vertices type must be Vec3f");
     CV_Assert(vertices.isContinuous());
     if (!colors.empty())
-        CV_CheckType(color_type, color_type == CV_8UC3 || color_type == CV_8UC4);
+        CV_CheckType(color_type, color_type == CV_8UC3 || color_type == CV_8UC4, "unsupported type");
 
     // material
     MaterialPtr mat = MaterialManager::getSingleton().create(name, RESOURCEGROUP_NAME);

modules/ximgproc/doc/ximgproc.bib

@@ -298,3 +298,16 @@
   volume = {1},
   booktitle = {VISAPP 2008 - 3rd International Conference on Computer Vision Theory and Applications, Proceedings}
 }
+
+@misc{Segleafvein,
+  title = {Best Way of Segmenting Veins in Leaves.},
+  author = {Niki Estner},
+  url = {https://dsp.stackexchange.com/a/1735}
+}
+
+@misc{M_RF,
+  title = {Ridge Filter Mathematica},
+  author = {Wolfram Mathematica},
+  url = {http://reference.wolfram.com/language/ref/RidgeFilter.html}
+
+}

modules/ximgproc/include/opencv2/ximgproc/ridgefilter.hpp

@@ -5,6 +5,7 @@
 /*
 Ridge Detection Filter.
 OpenCV port by : Kushal Vyas (@kushalvyas), Venkatesh Vijaykumar(@venkateshvijaykumar)
+Adapted from Niki Estner's explaination of RidgeFilter.
 */
 
 #ifndef __OPENCV_XIMGPROC_RIDGEFILTER_HPP__
@@ -20,7 +21,8 @@ namespace cv { namespace ximgproc {
 /** @brief  Applies Ridge Detection Filter to an input image.
 Implements Ridge detection similar to the one in [Mathematica](http://reference.wolfram.com/language/ref/RidgeFilter.html)
 using the eigen values from the Hessian Matrix of the input image using Sobel Derivatives.
-Additional refinement can be done using Skeletonization and Binarization.
+Additional refinement can be done using Skeletonization and Binarization. Adapted from @cite segleafvein and @cite M_RF
+
 */
 class CV_EXPORTS_W RidgeDetectionFilter : public Algorithm
 {