Using Qt as OpenCV HighGUI Backend for Mac OS X

Although I am in love with my new Macbook 12", I must admit that its X11 is quite annoying when used as OpenCV HighGUI's backend--it does not resize the image!

I was so frustrated with it that I looked for an alternative backend, and here it is: Qt5. In this tutorial, I will go over the method of building OpenCV3 on Mac OS X with Qt5 as HighGUI's backend. For simplicity, I will make use of homebrew.

First, you will need to tap into science:

$ brew tap homebrew/science

Next, install opencv3 with qt5 option:

$ brew install opencv3 --with-qt5

This option will add -D WITH_QT=ON in OpenCV's cmake option, thus linking Qt.

That's it! If you are wondering what are other available options, run

$ brew options opencv3

For more info on the package, run

$ brew info opencv3

That's it! You should now be able to launch HighGUI window via Qt5!