example build problem in 3.20 [closed]
I have expanded the info here - as requested.
I am a long time user of OpenCV. For the past several months been working with aruco on a very small embedded system using Ubuntu 15.10 and OpenCV 3.1/2. My development cycle starts on a large Intel system running Ubuntu 16.04. I develop the code on this, then copy the source to the armv7l/Ubuntu 15.10 embedded system, and recompile.
Size is limited on the embedded system, and I have successfully built and used aruco on a minimum OpenCV build (aruco, core, highui, imgproc, img_codecs, calib3d, features2d, flann and ml). The resulting static libs link and function properly with a small multi-threaded system that uses aruco for local position. This works both on the large Ubuntu 16.04 machine, and the embedded Ubuntu 15.10 one.
My problem is that I want to use the examples that come with aruco for marker creation and calibration. I only need this on the larger Intel/Ubuntu 16.04 system. I did not have any problem with this on 3.1. I simply used ccmake to set BUILD_EXAMPLES to ON, and recompiled.
But this does not seem to work any more. As far as I can tell, the system does not even try to compile the examples.
I am not getting any errors. I have tried building a fuller version of opencv - though not absolutely everything. About the only odd thing in my setup is that I limit it to static libs. So I tried it with shared libs with no change in results.
I have completely torn out opencv and restarted from new git clones. I have looked on this forum, and more broadly, for hints and have not discovered anything.
I can undoubtedly figure out how to compile the couple of tools I need, since the code is in the tree. But, I am thoughtful that it simply will not build any examples.
So - anybody have any thoughts as to what could be going on?
thanks much
Problem Solved: I resolved this by also building the videoio module. This module is not listed in the aruco CMakeLists.txt. However, inspection of the source of some of the samples made clear that it was needed. Adding it to the build caused the aruco samples to be built. For those interested, the executables were put in the bin directory of the build directory, as has been true in the past. And as usual, make install does NOT install them anywhere. Thanks for all the suggestions.
not enough information, to help you there.
but, since at some point, you don't want to build "examples", but your own program, have a look here
added more info - hope it helps
is it only the aruco examples, or are other ones missing, too ?
did you try to cd to the samples folder, and run cmake locally ?
can't reproduce the problem (on win, but using static libs, too) . all examples build fine.
can it simply be, you're unable to find them, because they end up in an unexpected place ? (install/samples/aruco here)
could you add the cmake output to your question ?
to answer the questions: no samples are built that I can find. I usually name the build directory 'release' and in the past the samples executables have been in 'opencv/release/bin'. This time it does not even make a bin. I did look inside the main samples folder, the aruco samples folder, the apps folder, and a few other places. No luck.
Can you give me more input on which cmake output files would be useful to see? I am not a ccmake/cmake/make maven.
I did try issuing cmake in the various samples folders - did not help. Either just ran the overall opencv config, or did nothing complaining that it could not find either the source or other relevant files