While I’m reporting on my computer mishaps (go here if you want to know how to install ITK), here’s another headslapper. (BTW, this applies to Snow Leopard/OS X 10.6.3.)

MacPorts is a command line tool for installing software, and I was trying it out for the end goal of getting ImageMagick on my computer. Installing MacPorts itself went smoothly. Then, as its documentation suggested, I tried to update by running sudo port -v selfupdate. “Tried” is the operative word, as I kept getting this:

Error: Unable to execute port: can't read "build.cmd": Failed to locate 'make' in
path: '/opt/local/bin:/opt/local/sbin:/bin:/sbin:/usr/bin:/usr/sbin' or at its
MacPorts configuration time location, did you move it?

No, you twit, I did not move it.

Sarcastic frustration being ineffective for compelling my computer to cooperate (whew alliteration of c-p sounds), I turned to Google and found that a few other people also experienced this problem. At least two arrived at resolution by (re)installing Xcode with Unix Development Support. I installed Xcode from my OS X install disc, and after that MacPorts updated properly. I’m not sure if the version of Xcode available online for download will also work.

Installing Insight Toolkit (ITK) shouldn’t be that hard to do, but I wasted a lot of time trying to figure this out, so I’ll share what I’ve learned. If you’re in a hurry, here’s the gist: go with CMake, it took about half an hour on my 2-gb, 2.13-ghz MacBook Air.

Since I have a Mac, specifically OS X 10.6 (Snow Leopard), I reduced my installation options to two routes: CMake and MacPorts. Both are free and run from the command line; CMake also has a GUI. Initially I tried MacPorts, since it seemed the easier of the two with a one-liner:

sudo port -d install InsightToolkit

For reference, here’s the wiki guide on ITK with MacPorts.

However, the process seemed to stall after several minutes, attempting to download something at ever decreasing speeds. I let it run all night and it still didn’t finish. The longer it went, the more the download rate slowed, like an annoying instance of Zeno’s paradox. So finally I ^C’ed outta there. I did try initiating the build again and it seemed to bypass the steps it had already taken but again stalled at a similar downloading step.

After that failure, I set about learning some of this CMake compiling business. I should have known to start there from the beginning, since CMake is from Kitware, the open-source software group responsible for ITK as well. Here’s what would have made my life easier if it had been spelled out for me:

1. Download and install CMake using the familiar and friendly .dmg format meant for simple folks like me.
2. Download ITK and unarchive the compressed file. This folder is the ITK source folder, which CMake will need.
3. CMake can be run from the command line or from a GUI. Since I’m feeling particularly noob, I went with the GUI. It looks something like this, once it is running (note the output in the bottom window):
   
   Set your Source (the ITK source folder that you downloaded) and the Build folder, which should be an empty new folder where you will build ITK. I called mine “ITK_bin.”
4. Click “Configure.” A window will pop up, asking you to “specify the generator for this project.” I went with the defaults on this and it worked. After you click “Done,” CMake will write files to the build directory. At some point it should have a red screen and ask you to choose from a set of options such as the one below:
   
   I unchecked “Build Examples” and “Build Testing” since I don’t need them. When you have set the options as you like, click “Configure” again. Repeat this until no new options are available, at which point the screen is no longer red.
5. At this point, you will need the command line, but this last step is very easy. Go to your ITK build directory and enter “make.” E.g., if I am in the parent folder of my ITK build directory,

   $ cd ITK_bin
   $ make

   ITK should start building, with progress displayed as [4%], [11%], and so forth.