openCV undefined symbols _cvCvtColor-Collection of common programming errors

In Terminal, “cd” to the directory that contains your OpenCV library (or actually libraries, as I see a few of them are built when I look at this “how to build OpenCV tutorial”) and then type in this command:

nm -arch x86_64 _________.a” (fill in the name of the library where the underscores are)

This dumps out all the symbols of the library. You can egrep or search for “cvCvtColor“.

My guess is that you’ve built OpenCV for 32-bit only (and this will be easy to see if you get absolutely no symbols when specifying “-arch x86_64” in the “nm” command) and that you need to also build your OpenCV libraries for 64-bit (x86_64).

Originally posted 2013-11-06 03:16:21.