Cocoapods OpenCV 2.4.10 Linker Error

Question

I\'m trying to build a simple project using OpenCV 2.4.10 but I get a bunch of errors like this:

Undefined symbols for architecture x86_64:
  \"_jpeg_free_large\", re         


        

Answer 1

So here's a little workaround. The problem is because the XCode project is unable to link to the libjpeg.a library. So thats why you get the above errors when you compile the project.

Follow these steps :

1. Go to : [[http://sourceforge.net/projects/libjpeg-turbo/files/1.4.0/]] and download the libjpeg-turbo-1.4.0.dmg (3.8 MB) file.
2. Install the package. Once its done you will find the installed files under this path : /opt/libjpeg-turbo/lib
3. Open up your terminal and type the following command : lipo -info /opt/libjpeg-turbo/lib/libjpeg.a
4. If the terminal shows the following the output after running the command then it means, you can use the library for your iOS project(armv7/armv7s)
   • Architectures in the fat file: /opt/libjpeg-turbo/lib/libturbojpeg.a are: i386 x86_64 armv6 armv7 armv7s arm64*
5. Use finder to navigate to : /opt/libjpeg-turbo/lib and copy libjpeg.a and place it in your project folder.
6. Head over to your XCode project -> Click on Project Name -> Targets -> General -> Linked frameworks and libraries -> Click on the add button placed at the bottom -> include the libjpeg.a file
7. Compile the project. It shouldn't show any more libjpeg linker errors.