Merge pull request #11589 from alalek:calib3d_chessboard_fix
authorAlexander Alekhin <alexander.a.alekhin@gmail.com>
Mon, 28 May 2018 10:13:42 +0000 (10:13 +0000)
committerAlexander Alekhin <alexander.a.alekhin@gmail.com>
Mon, 28 May 2018 10:13:43 +0000 (10:13 +0000)

Trivial merge