* fixed bug #11100 Integer overflow in kmeans

* fixed integer overflow in other divUp-s in kmeans code
fixed warning about size_t to double conversion

Apparently the blog has been updated and the URL has changed, it is still there though.

* Fix #9363

* Renamed the structure and added a new function to the LineSegmentDetectorImpl class as a static member

* Added a new function to the LineSegmentDetectorImpl class as a static member

also add comments explaining the change

add_dependencies(${target}) doesn't control regeneration of .apk file,
because "${target}" is dummy target.

color.cpp split (#10869)

* initial split is done

* files renamed (these names are excluded during compilation)

* IPP code moved to corresponding files

* splineBuild, splineInterpolate -> color_lab.cpp

* Lab, Luv: little refactored

* it compiles (didn't check work); Lab OCL code moved to color_lab.cpp

* cvtcolor.cl: Lab/Luv part moved to color_lab.cl

* cvtcolor.cl: color_rgb.cl extracted

* cvtcolor.cl: color_yuv.cl separated

* cvtcolor.cl: color_hsv.cl extracted

* cvtcolor.cl: extracted to color_lab.cl and color_rgb.cl

* helper functions moved to hpp file

* Lab, Luv: moved to color_lab.cpp

* CPU XYZ: to color_lab.cpp

* OCL XYZ: to color_lab.cpp

* warning fixed

* CvtHelper added

* CPU YUV: to color_yuv.cpp, helpers to color.hpp

* CPU HLS/HSV: to color_hsv.cpp

* CPU BGR2BGR: to color_rgb.cpp

* CPU RGB: to color_rgb.cpp

* extra arg removed

* CPU YUV: to color_yuv.cpp

* color code decoded

* OclHelper added, some funcs rewritten

* color_lab.cpp: refactored to use OclHelper

* OCL RGB: to color_rgb.cpp

* OCL HLS/HSV: to color_hsv.cpp

* OCL YUV: to color_yuv.cpp

* OCL YUV planes: to color_yuv.cpp

* OCL: color code reduced

* licence to demosaicing.cpp

* IPP func tables to color_rgb.cpp

* code cleanup

* HAVE_OPENCL ifdefs added

* helpers made more common

* fixed two plane YUV with separate mats

* fixed warning in gcc7.2.0

* precomp header fixed

* color space classification functions fixed

* helpers fixed

* rename: isSRGB -> is_sRGB

When compiling with OpenNI2 flag active, CMake will not be able to find OpenNI.h due to the environment path not set in OpenCVFindOpenNI2.cmake. This PR rectifies this issue.

destroyWindow was called twice during completion of the
annotation procedure, resulting in a crash, and failure to write
an output file

* Haiku supporting patches

* Revert uneeded changes

* Whitespace cleanup

This offsets text brightness of pixel brightness values
by offsetting it by 127 to the curent pixel value.
The text is now readable even if pixels are black.

Bug was added in f6ceeaa2 commit, different angle computation functions have different parameter order.

Fixed dynamic build script for iOS (#10923)

* Readded UIDeviceFamily (was removed in beec247)

* Added correct bitcode flag to python build script for iOS

* Missed the bitcodedisabled check

* Corrected the syntax in my proposed changes

  * add ifdef to apply on specific situation

* Fix #10948

* Add test code

* Fixed build error

* Add value zero

* eigen: test cleanup

Refactor decolor (#11035)

* decolor: modernize deprecated headers (math.h -> cmath)

* refactor contrast_preserve.cpp

* refactor contrast_preserve.hpp (add static/const)

* refactor contrast_preserve.hpp (join assignment and declaration)

* refactor contrast_preserve.hpp (format)

* refactor test_decolor.cpp (indent)

* refactor contrast_preserve.hpp (const)

* contrast_preserve.hpp : optimize by minMaxLoc

* fix trailing-whitespace

* fix warning C4267 on VC++ x64
(conversion from 'size_t' to 'int', possible loss of data)

* use cvRound instead of round_num

* decrease indentation of test_decolor.cpp

* remove pow() to optimize

* remove redundant Mat initialization

Enabling build of visualization module when using VTK 9 (current HEAD of d5bbb9e99bbc6d11d2196c48bfd8f33508554551)