- reduce scope of i,k,j variables
- use cv::AutoBuffer
- template<bool onlyDistance> class KMeansDistanceComputer
- eliminate manual unrolling: CV_ENABLE_UNROLLED

- don't use RNG for "task size" parameters (N, K, dims)
- add "good" kmeans test data (without singularities: K > unique points)

* Bit-exact implementation of GaussianBlur smoothing

* Added universal intrinsics based implementation for bit-exact CV_8U GaussianBlur smoothing.

* Added parallel_for to evaluation of bit-exact GaussianBlur

* Added custom implementations for 3x3 and 5x5 bit-exact GaussianBlur

* Fix for QT image window rectangle

* Update window_QT.h

* Update window_QT.cpp

* trailing whitespace

* highgui: fix QT getWindowImageRect()

* cuda::cvtColor bug fix

Fixed bug in conversion formula between RGB space and LUV space.
Testing with opencv_test_cudaimgproc.exe, this commit reduces the number
of failed tests from 191 to 95. (96 more tests pass)

* Rename variables

cut one ocl kernel if normVariance is disabled,
also use native_powr for performance reason.
Signed-off-by: NLi Peng <peng.li@intel.com>

Signed-off-by: NLi Peng <peng.li@intel.com>

Documentation generation refactoring (#10621)

* Documentation build updates:

- disable documentation by default, do not add to ALL target
- combine Doxygen and Javadoc
- optimize Doxygen html

* javadoc: fix path in build directory

* cmake: fix "Documentation" status line

Update to add window position and size retrieval to HighGUI (#10412)

* Update highgui.hpp

Add read only property retrieval for enhanced rendering capabilities and more sophisticated research tools

* Update window.cpp

* Update window_w32.cpp

* Update window_QT.cpp

* Update window_QT.h

* Update window_QT.h

* Update window_gtk.cpp

* Update precomp.hpp

* Update highgui_c.h

* Update highgui_c.h

* Update window_w32.cpp

* Update precomp.hpp

* Update window_QT.cpp

* Update window_QT.h

* Update window_gtk.cpp

* Update window_gtk.cpp

* Update window_w32.cpp

* Update window_QT.cpp

* Update window_carbon.cpp

* Update window_cocoa.mm

* Update precomp.hpp

* Update window_cocoa.mm

* Update window_w32.cpp

* Update window_gtk.cpp

* Update window_QT.cpp

* Update window_gtk.cpp

* Update window_QT.cpp

* Update window_cocoa.mm

* Update window_carbon.cpp

* Update window_w32.cpp

* Update window_cocoa.mm

* Update window_gtk.cpp

* Update window_cocoa.mm

* Update window_gtk.cpp

* Update window_cocoa.mm

* Update window_cocoa.mm

* Update window.cpp

* Update test_gui.cpp

* Update test_gui.cpp

* Update test_gui.cpp

* Update highgui_c.h

* Update highgui.hpp

* Update window.cpp

* Update highgui_c.h

* Update test_gui.cpp

* Update highgui.hpp

* Update window.cpp

* Update window.cpp

* Update window.cpp

* Update window.cpp

* Update window.cpp

Re-apply protobuf fix for JavaScript builds

original commit: f5035150
JavaScript bindings for dnn module

and add parametric unit test for crop layer.

* Newton's method can be more efficient

when we get the result of function distortPoint with a point (0, 0) and then undistortPoint with  the result, we get the point not (0, 0). and then we discovered that the old method is not convergence sometimes. finally we have gotten the right values by Newton's method.

* modify by advice  Newton's method...#10574

* calib3d(fisheye): fix codestyle, update theta before exit EPS check

Signed-off-by: NLi Peng <peng.li@intel.com>

Signed-off-by: NLi Peng <peng.li@intel.com>

When compiling with cmake using -DCMAKE_CXX_STANDARD=11 use `-std=gnu++11`
for PCH compiler flags, otherwise it triggers an error:

   opencv_core_Release.gch: not used because `__cplusplus' defined as ` 201103L' not ` 199711L' [-Winvalid-pch]

Use CXX_EXTENSIONS property to select `gnu++11` or `c++11`.
Trying to mimic cmake logic here: https://gitlab.kitware.com/cmake/cmake/blob/master/Source/cmLocalGenerator.cxx#L1527-1557