* Add Sobel kernel which returns both dx and dy
* Splice dx and dy and extend add_border function
Also change some tests parameters
* Add borderValue parameter in test
* Introduces fluid kernel for sobelxy
Adds tests (basic and performance) on new backend
* Introduces BufHelper struct for some arithmetic
More fixes for G-API tests (#13251)
* scalar comparator and more fixes for tests
* add weighted aligned
* white space
* more white space
* Add weighted test accuracy check enabled
GAPI (fluid): optimization of Separable filter (#13221)
* GAPI (fluid): Separable filter: performance test
* GAPI (fluid): enable all performance tests
* GAPI: separable filters: alternative code for Sobel
* GAPI (fluid): hide unused old code for Sobel filter
* GAPI (fluid): especial code for Sobel if U8 into S16
* GAPI (fluid): back to old code for Sobel
* GAPI (fluid): run_sepfilter3x3_impl() with CPU dispatcher
* GAPI (fluid): run_sepfilter3x3_impl(): fix compiler warnings
* GAPI (fluid): new engine for separable filters (but Sobel)
* GAPI (fluid): new performance engine for Sobel
* GAPI (fluid): Sepfilters performance: fixed compilation error
G-API GPU-OpenCL backend (#13008)
* gpu/ocl backend core
* accuracy tests added and adjusted + license headers
* GPU perf. tests added; almost all adjusted to pass
* all tests adjusted and passed - ready for pull request
* missing license headers
* fix warning (workaround RGB2Gray)
* fix c++ magic
* precompiled header
* white spaces
* try to fix warning and blur test
* try to fix Blur perf tests
* more alignments with the latest cpu backend
* more gapi tests refactoring + 1 more UB issue fix + more informative tolerance exceed reports
* white space fix
* try workaround for SumTest
* GAPI_EXPORTS instead CV_EXPORTS
Made scale parameter optional for mul kernel wrapper (#12949)
* Added missed operator*(GMat, GMat). Made scale parameter optional for mul kernel.
* Fixed perf test for mul(GMat, GMat) kernel
* Removed operator*(GMat, GMat) as not needed
* Renamed Sobel operator GAPI kernel to match with OpenCV naming rules
* Fixed perf tests
* Small refactoring to check CI issue
* Refactored alignment for kernel wrappers in imgproc.hpp
* G-API Initial code upload
* Update G-API code base to Sep-24-2018
* The majority of OpenCV buildbot problems was addressed
* Update G-API code base to 24-Sep-18 EOD
* G-API code base update 25-Sep-2018
* Linux warnings should be resolved
* Documentation build should become green
* Number of Windows warnings should be reduced
* Update G-API code base to 25-Sep-18 EOD
* ARMv7 build issue should be resolved
* ADE is bumped to latest version and should fix Clang builds for macOS/iOS
* Remaining Windows warnings should be resolved
* New Linux32 / ARMv7 warnings should be resolved
* G-API code base update 25-Sep-2018-EOD2
* Final Windows warnings should be resolved now
* G-API code base update 26-Sep-2018
* Fixed issues with precompiled headers in module and its tests
