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

modules/ovis/include/opencv2/ovis.hpp

@@ -248,6 +248,11 @@ CV_EXPORTS_W void addResourceLocation(const String& path);
  * @param title window title
  * @param size size of the window
  * @param flags a combination of @ref SceneSettings
+ *
+ * Furthermore, the behavior is controlled by the following environment variables
+ * - OPENCV_OVIS_VERBOSE_LOG: print all of OGRE log output
+ * - OPENCV_OVIS_RENDERSYSTEM: the name of the OGRE RenderSystem to use
+ * - OPENCV_OVIS_NOVSYNC: disable VSYNC for all windows
  */
 CV_EXPORTS_W Ptr<WindowScene> createWindow(const String& title, const Size& size,
                                            int flags = SCENE_INTERACTIVE | SCENE_AA);

modules/ximgproc/include/opencv2/ximgproc.hpp

@@ -184,7 +184,7 @@ CV_EXPORTS_W void thinning( InputArray src, OutputArray dst, int thinningType =
 
  \f[ c\left(\|\nabla I\|\right)={\frac {1}{1+\left({\frac  {\|\nabla I\|}{K}}\right)^{2}}} \f]
 
- @param src Grayscale Source image.
+ @param src Source image with 3 channels.
  @param dst Destination image of the same size and the same number of channels as src .
  @param alpha The amount of time to step forward by on each iteration (normally, it's between 0 and 1).
  @param K sensitivity to the edges