Merge pull request #12668 from alalek:calib3d_chessboardsb_updates
authorAlexander Alekhin <alexander.a.alekhin@gmail.com>
Sun, 30 Sep 2018 21:00:01 +0000 (00:00 +0300)
committerGitHub <noreply@github.com>
Sun, 30 Sep 2018 21:00:01 +0000 (00:00 +0300)

Trivial merge