* Add python version of panorama_stitching_rotating_camera and perspective_correction

* Updated code

* added in the docs

* added python code in the docs

* docs change

* Add java tutorial as well

* Add toggle in documentation

* Added the link for Java code

* format code

* Refactored code

Python code examples for file IO in xml and yml format

* Initial "Pythonization" of file_input_output.cpp

* Moved file_input_output.py to correct location

* Nearly done Pythonizing file_input_output.cpp

* Python equivalent of file_input_output.py created

* Started Pythonizing camera_calibration.cpp

* Completed Python tutorial/sample code for file_input_output

* Resolved whitespace issues

* Removed tabs in file_input_output.cpp

* Patched import order and wrapped code in main function

* Changed string to docstring format in help file

* Updated link to Python example code

pylint 1.8.3

Found via `codespell -q 3 -S ./3rdparty,./modules -L amin,ang,atleast,dof,endwhile,hist,uint`

backporting of commit: 32aba5e6

Fix Python code, for the tutorial_laplace_operator, to get the same result between the Cpp, Java and Python

* cast positional arguments to int

* Changed to integer division based

* removed white space

* removed white space

because t = (time.time() - t) will return seconds,  dividing by 1000 to obtain seconds will be incorrect.

Extend optical flow tutorial (#14314)

* extend python optical flow tutorial with cpp example code and add it to general tutorial directory

* remove unused parameters, fix comparison between signed and unsigned int

* fix hsv range problem

* switch to samples::findFile for sample file location

* switch to command line parameter for path

* remove old tutorial as in 14393

* minor fixes

Extend meanshift tutorial (#14393)

* copy original tutorial and python code

* add cpp code, fix python code

* add camshift cpp code, fix bug in meanshift code

* add description to ToC page

* fix shadowing previous local declaration

* fix grammar: with -> within

* docs: remove content of old py_meanshift tutorial, add link

* docs: replace meanshift tutorial subpage in Python tutorials

* switch to ref to fix wrong breadcrumb navigation

* switch to cmdline for path as in #14314

* Apply suggestions from code review

* order programming languages alphabetically

* Created python version of the code for the anisotropic image segmentation tutorial. Created python/cpp toggles for the markdown file.

* fix doxygen warnings

find innercircle of contour by using pointPolygonTest: (#12206)

      - Changing the contrast and brightness of an image!
      - Operations with images

Add Java and Python code for AKAZE local features matching tutorial. Fix incorrect uses of Mat.mul() in Java code.

Uniform Lowe's ratio test in the code.

Add Java and Python code for Image Segmentation with Distance Transform and Watershed Algorithm tutorial. Use more Pythonic code.

Add Java and Python code for the following imgproc tutorials: Finding contours in your image, Convex Hull, Creating Bounding boxes and circles for contours, Creating Bounding rotated boxes and ellipses for contours, Image Moments, Point Polygon Test.

Tested with:
- pylint 1.9.1

Add Java and Python code for the following features2d tutorials: Harris corner detector, Shi-Tomasi corner detector, Creating your own corner detector, Detecting corners location in subpixels, Feature Detection, Feature Description, Feature Matching with FLANN, Features2D + Homography to find a known object. Use Lowe's ratio test to filter the matches.

Add Java and Python code for the following imgproc tutorials: Affine Transformations, Histogram Equalization, Histogram Calculation, Histogram Comparison, Back Projection.

Add Java and Python code for the following imgproc tutorials: Canny, Remap, threshold and threshold inRange. Use HSV colorspace instead of RGB for inRange threshold tutorial.

* hogsvm compatibility with python3