Added gradiantSize param into goodFeaturesToTrack API (#9618)

* Added gradiantSize param into goodFeaturesToTrack API

Removed hardcode value 3 in goodFeaturesToTrack API, and
added new param 'gradinatSize' in this API so that user can
pass any gradiant size as 3, 5 or 7.
Signed-off-by: Vipin Anand <anand.vipin@gmail.com>
Signed-off-by: Nilaykumar Patel<nilay.nilpat@gmail.com>
Signed-off-by: Prashanth Voora <prashanthx85@gmail.com>

* fixed compilation error for java test
Signed-off-by: Vipin Anand <anand.vipin@gmail.com>

* Modifying code for previous binary compatibility and fixing other warnings

fixed ABI break issue

resolved merged conflict

compilation error fix
Signed-off-by: Vipin Anand <anand.vipin@gmail.com>
Signed-off-by: Patel, Nilaykumar K <nilay.nilpat@gmail.com>

Update planar_tracking.cpp (#9686)

Add demo code for cv::reduce, cv::merge and cv::split.

* Adds cv::resizeWindow() overload taking a single cv::Size argument.

* Replaces copied documentaion with Doxygen @overload command.

Add constructors taking initializer_list for some of OpenCV data types (#9034)

* Add a constructor taking initializer_list for Matx

* Add a constructor taking initializer list for Mat and Mat_

* Add one more method to initialize Mat to the corresponding tutorial

* Add a note how to initialize Matx

* CV_CXX_11->CV_CXX11

Remove unnecessary Non-ASCII characters from source code (#9075)

* Remove unnecessary Non-ASCII characters from source code

Remove unnecessary Non-ASCII characters and replace them with ASCII
characters

* Remove dashes in the @param statement

Remove dashes and place single space in the @param statement to keep
coding style

* misc: more fixes for non-ASCII symbols

* misc: fix non-ASCII symbol in CMake file

*Fixing typos;
*Making codes more similar to the main one, in C++;
*Adding Grayscale option to the Python and Java codes;
*Fixing python identation, whitespaces and redundancies.

* Extending template_matching tutorial with Java

* adding mask to java version of the tutorial

* adding the python toggle and code

* updating table of content

* adding py and java to table of content

* adding mask to python

* going back to markdown with duplicated text

* non duplicated text

Fix bug in camera_calibration.cpp that the program tries to
parse input of type VIDEO_FILE as IMAGE_LIST which causes the
program to crash.

Increase readability by using namespace std

If-condition was always true (alpha = 0.5 is set in Line 19).
Now the user input is checked to be between 0 and 1.
This is correct in the tutorial code for OpenCV 2.4.

Fix error usage in HitMiss tutorial, and improved the visualization results (#7978)

* Fix error usage in HitMiss tutorial, and improved the visualization results

Fix error usage in HitMiss tutorial, and improved the visualization results

* Update HitMiss.cpp

* Update HitMiss.cpp

Use directly the doxygen snippet command for the Changing the contrast and brightness of an image tutorial. Extend the tutorial with a pratical example and with a gamma correction method to adjust the brightness of an image.