Prevent division by zero
White space and spelling in meanshift tutorial

Removed a leading whitespace from a parenthetical comment and corrected the spelling of "maybe"
Fixed typo in description of Rect operations
Python test: added options to provide local data path
Remove unnecesary operations and calculations in loop body.

Signed-off-by: Yan Wang <yan.wang@linux.intel.com>
Use sincos instead of sin and cos.

Signed-off-by: Yan Wang <yan.wang@linux.intel.com>
It turns opengl gheck is not needed for win ctrl+s
Make Ctrl+S open save dialog on Gtk backend
Merge pull request #3482 from wangyan42164:ocl_brute_match_improve
Merge pull request #3483 from wangyan42164:ocl_orb_improve
Merge pull request #3481 from mshabunin:python-test
Merge pull request #3478 from akarsakov:rect_fix_typo
Merge pull request #3475 from fhsm:master
Merge pull request #3472 from Dmitry-Me:preventDivByZero
Merge pull request #3487 from taka-no-me:ctrl_s_gtk