Tag Archives: homebrew

Installing OpenKinect and OpenCV the easy way on a Mac

Edit: I now have a new slightly polished cocoa-freenect wrapper for use in your Kinect-Cocoa projects! Check out the post here. On the repo there also new and improved installation instructions!

For ages I tried to find an easy way to install both libfreenect (OpenKinect) and OpenCV on my mac without having to follow loads of lines of instructions and getting lots of errors in the process.

So, after quite a while of searching around for an easy install, which didn’t involve me installing loads of different package managers, I came across these methods which work really nicely 🙂

First, Install Homebrew, if you don’t have it already:

  • It’s super easy… just follow the instruction… GO!
  • That was crazy fast, now do one of these, or both, or none…


  • If you still have your terminal open type in (or copy and paste) these commands one at a time and press enter.
cd /usr/local/Library/Formula


curl --insecure -O "https://raw.github.com/OpenKinect/libfreenect/master/platform/osx/homebrew/libfreenect.rb"
curl --insecure -O "https://raw.github.com/OpenKinect/libfreenect/master/platform/osx/homebrew/libusb-freenect.rb"
brew install libfreenect
  • Then, once all thats finished you’re done for OpenKinect 🙂 you can give it a test by typing this into the terminal (as long as your still in the install directory..)

OpenCV (2.3.1a):

  • Now, OpenCV is even easier again! Just type in (or copy and paste again) this command:
brew install opencv
  • This one takes a bit longer than OpenKinect…
  • And then, You’re all done!
  • You can close terminal now 🙂

Now the last task. If you want to use these libraries in Xcode just follow these steps:

  • These instructions are for Xcode 4 by the way. Sorry Xcode 3 people, I started using Xcode from version 4.. But don’t worry Xcode 3 people, if you know what you’re doing then this is pretty much the same process as using the built in Mac libraries.
  • If your creating a Cocoa application it’s a little simpler:
    • Open your YourApp.xcodeproj file
    • Select the target you want to add it to, there will usually only be one
    • Then click “Summary”
    • And under “Linked Frameworks and Libraries” press the plus button
    • In the search field that shows up type in “libfreenect”
    • You will see all the libraries that begin with libfreenect. So now you can choose one 🙂 I usually use libfreenect_sync because it is easier to use this in objective-c programs, from what I have seen so far. So select the latest version of it that shows up.
    • That’s it for that. Now to include it in your application code just type this #import <libfreenect/libfreenect_sync.h>
  • Now, if it isn’t a Cocoa application but a Console application do these things:
    • Open your YourApp.xcodeproj file
    • Select the target you want to add it to
    • Click on the “Build Phases” tab
    • Then under “Link Binary With Libraries” press the plus button
    • In the search field that shows up type in “libfreenect”
    • Now you can select which library you would like to use as I discussed in the second to last point of the Cocoa app method.
    • All done!

So now you should be all sorted with OpenKinect and OpenCV (the libraries when searching are called libopencv… there are quite a few tho, don’t really wanna go into what does what and what you need and all that… I don’t really know that myself just yet..)

Anyways, bye bye everyone

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I am the Kinect Master!!

So, it took me about a week of very frustrating research, fixes, failures of fixes, getting libraries installed and some not installing to finally get some proper synchronous data back from the Kinect into my program.

There were so many things going wrong its hard to actually remember it all.. but here is what I can remember:

Firstly I set up my objective-c program to use the libfreenect_sync.h library along with OpenGL to display the RGB and Depth images in the view in my program. This worked fine for the RGB feed but the Depth feed was just a mess. The images it displayed were messed up. It was like there was a load of overlapping and static like you used to see on TV’s. So I went out to try and fix this.

One fix that I found was to change the OpenGL glTexImage2D setting to GL_RGB for depth and change the input resolution to 320 by 420 pixels. This seemed to fix things a bit but the image looked a bit low res compared to the glview example.

I then tried LOOADS of other ways to fix it, thinking that it was something wrong with my OpenGL settings but nothing worked.. I eventually attempted to install OpenCV again on my mac and it turned out that the easiest and most straightforward way to do it was to just (using homebrew) type this into Terminal:

sudo brew update
sudo brew install opencv

I think if you then restart Xcode the libraries will show up when you try to add linked frameworks and libraries under “libopencv…”.

So, I got OpenCV installed and I was able to test the c_sync example that was available here (switching it from video being displayed to depth). I then found out that it wasn’t my programming that was causing the problems it was something else.

After a lot more playing and searching I found a OpenCV Kinect example that uses the libfreenect_cv.h wrapper. And this seemed to use the libfreenect_sync.h header and still be able to display proper depth information. So I tinkered with this and eventually was able to recreate it in my own program using the same libfreenect_cv.h wrapper 🙂

The next step was to recreate it again but in my Objective-C program. Which also worked. And then finally I created my own Objective-C class which allowed me to easily control the Kinect and get data from it 🙂

(I think the real reason I couldn’t get it working was to do with a certain function I couldn’t get working myself… the function that seems to have a lot of switch-case statements in.)

So, there we are, I finally got it working 😀 only took a week… grr… so now I just have to work out how I can use OpenCV to help me pick out the objects to avoid in the room and find the Helicopter then track it.


Just after I got my Objective-C Kinect class working 🙂

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