All parameters can be set via json.
Conversion to grayscale only if required.
Merge pull request #11 from simonfojtu/qrdecode

Conversion to grayscale only if required.
Merge pull request #13 from simonfojtu/res-est-param

All parameters of HoughCircles and Points2Resolution stages can be set via json.
estimate-px-per-mm.json
...
PNG vs JPG
revised estimate-px-per-mm test
cross compiled raspberry pi opencv 2.4.8
remove-opencv-2.3
Merge remote-tracking branch 'refs/remotes/origin/dev' into dev
opencv-2.4.8