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

Revert "documentation: avoid links to 'master' branch from 3.4 maintenance branch"
This reverts commit 9ba9358ecb.

Revert "documentation: avoid links to 'master' branch from 3.4 maintenance branch (2)"
This reverts commit f185802489.

doc/tutorials/features2d/trackingmotion/corner_subpixeles/corner_subpixeles.markdown

@@ -1,32 +0,0 @@
-Detecting corners location in subpixeles {#tutorial_corner_subpixeles}
-========================================
-
-Goal
-----
-
-In this tutorial you will learn how to:
-
--   Use the OpenCV function @ref cv::cornerSubPix to find more exact corner positions (more exact
-    than integer pixels).
-
-Theory
-------
-
-Code
-----
-
-This tutorial code's is shown lines below. You can also download it from
-[here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/TrackingMotion/cornerSubPix_Demo.cpp)
-@include samples/cpp/tutorial_code/TrackingMotion/cornerSubPix_Demo.cpp
-
-Explanation
------------
-
-Result
-------
-
-![](images/Corner_Subpixeles_Original_Image.jpg)
-
-Here is the result:
-
-![](images/Corner_Subpixeles_Result.jpg)

doc/tutorials/features2d/trackingmotion/corner_subpixels/corner_subpixels.markdown

@@ -0,0 +1,46 @@
+Detecting corners location in subpixels {#tutorial_corner_subpixels}
+=======================================
+
+Goal
+----
+
+In this tutorial you will learn how to:
+
+-   Use the OpenCV function @ref cv::cornerSubPix to find more exact corner positions (more exact
+    than integer pixels).
+
+Theory
+------
+
+Code
+----
+
+@add_toggle_cpp
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/TrackingMotion/cornerSubPix_Demo.cpp)
+@include samples/cpp/tutorial_code/TrackingMotion/cornerSubPix_Demo.cpp
+@end_toggle
+
+@add_toggle_java
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/TrackingMotion/corner_subpixels/CornerSubPixDemo.java)
+@include samples/java/tutorial_code/TrackingMotion/corner_subpixels/CornerSubPixDemo.java
+@end_toggle
+
+@add_toggle_python
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/master/samples/python/tutorial_code/TrackingMotion/corner_subpixels/cornerSubPix_Demo.py)
+@include samples/python/tutorial_code/TrackingMotion/corner_subpixels/cornerSubPix_Demo.py
+@end_toggle
+
+Explanation
+-----------
+
+Result
+------
+
+![](images/Corner_Subpixels_Original_Image.jpg)
+
+Here is the result:
+
+![](images/Corner_Subpixels_Result.jpg)

doc/tutorials/features2d/trackingmotion/generic_corner_detector/generic_corner_detector.markdown

@@ -1,5 +1,5 @@
-Creating yor own corner detector {#tutorial_generic_corner_detector}
-================================
+Creating your own corner detector {#tutorial_generic_corner_detector}
+=================================
 
 Goal
 ----
@@ -10,7 +10,7 @@ In this tutorial you will learn how to:
     to determine if a pixel is a corner.
 -   Use the OpenCV function @ref cv::cornerMinEigenVal to find the minimum eigenvalues for corner
     detection.
--   To implement our own version of the Harris detector as well as the Shi-Tomasi detector, by using
+-   Implement our own version of the Harris detector as well as the Shi-Tomasi detector, by using
     the two functions above.
 
 Theory
@@ -19,10 +19,26 @@ Theory
 Code
 ----
 
+@add_toggle_cpp
 This tutorial code's is shown lines below. You can also download it from
 [here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/TrackingMotion/cornerDetector_Demo.cpp)
 
-@include cpp/tutorial_code/TrackingMotion/cornerDetector_Demo.cpp
+@include samples/cpp/tutorial_code/TrackingMotion/cornerDetector_Demo.cpp
+@end_toggle
+
+@add_toggle_java
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/TrackingMotion/generic_corner_detector/CornerDetectorDemo.java)
+
+@include samples/java/tutorial_code/TrackingMotion/generic_corner_detector/CornerDetectorDemo.java
+@end_toggle
+
+@add_toggle_python
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/master/samples/python/tutorial_code/TrackingMotion/generic_corner_detector/cornerDetector_Demo.py)
+
+@include samples/python/tutorial_code/TrackingMotion/generic_corner_detector/cornerDetector_Demo.py
+@end_toggle
 
 Explanation
 -----------

doc/tutorials/features2d/trackingmotion/good_features_to_track/good_features_to_track.markdown

@@ -6,7 +6,7 @@ Goal
 
 In this tutorial you will learn how to:
 
--   Use the function @ref cv::goodFeaturesToTrack to detect corners using the Shi-Tomasi method.
+-   Use the function @ref cv::goodFeaturesToTrack to detect corners using the Shi-Tomasi method (@cite Shi94).
 
 Theory
 ------
@@ -14,9 +14,23 @@ Theory
 Code
 ----
 
+@add_toggle_cpp
 This tutorial code's is shown lines below. You can also download it from
 [here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/TrackingMotion/goodFeaturesToTrack_Demo.cpp)
 @include samples/cpp/tutorial_code/TrackingMotion/goodFeaturesToTrack_Demo.cpp
+@end_toggle
+
+@add_toggle_java
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/TrackingMotion/good_features_to_track/GoodFeaturesToTrackDemo.java)
+@include samples/java/tutorial_code/TrackingMotion/good_features_to_track/GoodFeaturesToTrackDemo.java
+@end_toggle
+
+@add_toggle_python
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/master/samples/python/tutorial_code/TrackingMotion/good_features_to_track/goodFeaturesToTrack_Demo.py)
+@include samples/python/tutorial_code/TrackingMotion/good_features_to_track/goodFeaturesToTrack_Demo.py
+@end_toggle
 
 Explanation
 -----------
@@ -24,4 +38,4 @@ Explanation
 Result
 ------
 
-![](images/Feature_Detection_Result_a.jpg)
+![](images/good_features_to_track_Shi_Tomasi.jpg)

doc/tutorials/features2d/trackingmotion/harris_detector/harris_detector.markdown

@@ -118,9 +118,23 @@ In this tutorial we will study the *corner* features, specifically.
 Code
 ----
 
+@add_toggle_cpp
 This tutorial code's is shown lines below. You can also download it from
 [here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/TrackingMotion/cornerHarris_Demo.cpp)
 @include samples/cpp/tutorial_code/TrackingMotion/cornerHarris_Demo.cpp
+@end_toggle
+
+@add_toggle_java
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/master/samples/java/tutorial_code/TrackingMotion/harris_detector/CornerHarrisDemo.java)
+@include samples/java/tutorial_code/TrackingMotion/harris_detector/CornerHarrisDemo.java
+@end_toggle
+
+@add_toggle_python
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/master/samples/python/tutorial_code/TrackingMotion/harris_detector/cornerHarris_Demo.py)
+@include samples/python/tutorial_code/TrackingMotion/harris_detector/cornerHarris_Demo.py
+@end_toggle
 
 Explanation
 -----------