我在Ubuntu 16.04中使用Qt创建者来构建一个非Qt项目。我需要使用SIFT来检测功能。我知道SIFT和SURF在OpenCV_contrib中，所以我在使用Cmake-gui配置OpenCV时添加了额外的模块。
然后我可以在/ usr / local / lib中找到libopencv_xfeatures2d.so/.so.3.2/.so.3.2.0以及libopencv_features2d.so/.so.3.2/.so.3.2.0
当我使用OpenCV官方网站的代码时： [来自OpenCV官方网站的SIFT代码] [1]
测试SIFT，我仍然收到错误
/home/ronjane92/Documents/Qt/OpenCV/build/lib/libslam_essentials.so:-1: error: undefined reference to `cv::xfeatures2d::SIFT::create(int, int, double, double, double)'
:-1: error: collect2: error: ld returned 1 exit status
我的 CMakeLists.txt 包含以下内容：
CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
PROJECT(opencv_test)
include( CheckCXXCompilerFlag )
SET(CMAKE_CXX_FLAGS "-std=c++11 ${CMAKE_CXX_FLAGS}")
FIND_PACKAGE( PCL 1.7 REQUIRED COMPONENTS common io visualization)
ADD_DEFINITIONS( ${PCL_DEFINITIONS} )
INCLUDE_DIRECTORIES( ${PCL_INCLUDE_DIRS} )
LINK_DIRECTORIES( ${PCL_LIBRARY_DIRS} )
ADD_SUBDIRECTORY(lib)
INCLUDE_DIRECTORIES( ${PROJECT_SOURCE_DIR}/lib )
LINK_DIRECTORIES( ${PROJECT_BINARY_DIR}/lib )
FIND_PACKAGE( OpenCV 3.1.0 REQUIRED )
INCLUDE_DIRECTORIES( ${OpenCV_INCLUDE_DIRS} )
ADD_EXECUTABLE(${PROJECT_NAME} "main.cpp")
TARGET_LINK_LIBRARIES(opencv_test ${OpenCV_LIBRARIES}
${PCL_LIBRARIES}
realsense
slam_essentials
)
Cmake-gui的结果是
Detected version of GNU GCC: 54 (504)
FP16: Feature disabled
Found ZLIB: /usr/lib/x86_64-linux-gnu/libz.so (found suitable version "1.2.8", minimum required is "1.2.3")
Found ZLIB: /usr/lib/x86_64-linux-gnu/libz.so (found version "1.2.8")
Found OpenEXR: /usr/lib/x86_64-linux-gnu/libIlmImf.so
Checking for module 'gstreamer-base-1.0'
No package 'gstreamer-base-1.0' found
Checking for module 'gstreamer-video-1.0'
No package 'gstreamer-video-1.0' found
Checking for module 'gstreamer-app-1.0'
No package 'gstreamer-app-1.0' found
Checking for module 'gstreamer-riff-1.0'
No package 'gstreamer-riff-1.0' found
Checking for module 'gstreamer-pbutils-1.0'
No package 'gstreamer-pbutils-1.0' found
Checking for module 'gstreamer-base-0.10'
No package 'gstreamer-base-0.10' found
Checking for module 'gstreamer-video-0.10'
No package 'gstreamer-video-0.10' found
Checking for module 'gstreamer-app-0.10'
No package 'gstreamer-app-0.10' found
Checking for module 'gstreamer-riff-0.10'
No package 'gstreamer-riff-0.10' found
Checking for module 'gstreamer-pbutils-0.10'
No package 'gstreamer-pbutils-0.10' found
Looking for linux/videodev.h
Looking for linux/videodev.h - not found
Looking for linux/videodev2.h
Looking for linux/videodev2.h - found
Looking for sys/videoio.h
Looking for sys/videoio.h - not found
WARNING, PrimeSensor Module binaries directory (set by OPENNI_PRIME_SENSOR_MODULE_BIN_DIR variable) is not found or does not have PrimeSensor Module binaries.
Checking for module 'libavresample'
No package 'libavresample' found
Checking for module 'libgphoto2'
No package 'libgphoto2' found
Found TBB: /usr/lib/x86_64-linux-gnu/libtbb.so
found IPP (ICV version): 9.0.1 [9.0.1]
at: /home/ronjane92/Programs/opencv/opencv-3.2.0-build/3rdparty/ippicv/ippicv_lnx
Could not find OpenBLAS lib. Turning OpenBLAS_FOUND off
Could NOT find Atlas (missing: Atlas_CLAPACK_INCLUDE_DIR)
Could NOT find JNI (missing: JAVA_INCLUDE_PATH JAVA_INCLUDE_PATH2 JAVA_AWT_INCLUDE_PATH)
Could NOT find Matlab (missing: MATLAB_MEX_SCRIPT MATLAB_INCLUDE_DIRS MATLAB_ROOT_DIR MATLAB_LIBRARIES MATLAB_LIBRARY_DIRS MATLAB_MEXEXT MATLAB_ARCH MATLAB_BIN)
The imported target "vtkRenderingPythonTkWidgets" references the file
"/usr/lib/x86_64-linux-gnu/libvtkRenderingPythonTkWidgets.so"
but this file does not exist. Possible reasons include:
* The file was deleted, renamed, or moved to another location.
* An install or uninstall procedure did not complete successfully.
* The installation package was faulty and contained
"/usr/lib/cmake/vtk-6.2/VTKTargets.cmake"
but not all the files it references.
The imported target "vtk" references the file
"/usr/bin/vtk"
but this file does not exist. Possible reasons include:
* The file was deleted, renamed, or moved to another location.
* An install or uninstall procedure did not complete successfully.
* The installation package was faulty and contained
"/usr/lib/cmake/vtk-6.2/VTKTargets.cmake"
but not all the files it references.
Found VTK ver. 6.2.0 (usefile: /usr/lib/cmake/vtk-6.2/UseVTK.cmake)
Caffe: NO
Protobuf: YES
Glog: NO
freetype2: YES
harfbuzz: YES
Module opencv_sfm disabled because the following dependencies are not found: Glog/Gflags
freetype2: YES
harfbuzz: YES
Checking for modules 'tesseract;lept'
No package 'tesseract' found
No package 'lept' found
Tesseract: NO
Check contents of vgg_generated_48.i ...
Check contents of vgg_generated_64.i ...
Check contents of vgg_generated_80.i ...
Check contents of vgg_generated_120.i ...
Check contents of boostdesc_bgm.i ...
Check contents of boostdesc_bgm_bi.i ...
Check contents of boostdesc_bgm_hd.i ...
Check contents of boostdesc_binboost_064.i ...
Check contents of boostdesc_binboost_128.i ...
Check contents of boostdesc_binboost_256.i ...
Check contents of boostdesc_lbgm.i ...
General configuration for OpenCV 3.2.0 =====================================
Version control: unknown
Extra modules:
Location (extra): /home/ronjane92/Programs/opencv/opencv_contrib-3.2.0/modules
Version control (extra): unknown
Platform:
Timestamp: 2017-09-16T18:20:02Z
Host: Linux 4.8.0-58-generic x86_64
CMake: 3.5.1
CMake generator: Unix Makefiles
CMake build tool: /usr/bin/make
Configuration: Release
C/C++:
Built as dynamic libs?: YES
C++ Compiler: /usr/bin/c++ (ver 5.4.0)
C++ flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -Wno-comment -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -ffunction-sections -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG -DNDEBUG
C++ flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -Wno-comment -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -ffunction-sections -fvisibility=hidden -fvisibility-inlines-hidden -g -O0 -DDEBUG -D_DEBUG
C Compiler: /usr/bin/cc
C flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -Wno-comment -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -ffunction-sections -fvisibility=hidden -O3 -DNDEBUG -DNDEBUG
C flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -Wno-comment -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -ffunction-sections -fvisibility=hidden -g -O0 -DDEBUG -D_DEBUG
Linker flags (Release):
Linker flags (Debug):
ccache: NO
Precompiled headers: YES
Extra dependencies: Qt5::Test Qt5::Concurrent Qt5::OpenGL /usr/lib/x86_64-linux-gnu/libwebp.so /usr/lib/x86_64-linux-gnu/libjasper.so /usr/lib/x86_64-linux-gnu/libImath.so /usr/lib/x86_64-linux-gnu/libIlmImf.so /usr/lib/x86_64-linux-gnu/libIex.so /usr/lib/x86_64-linux-gnu/libHalf.so /usr/lib/x86_64-linux-gnu/libIlmThread.so dc1394 avcodec-ffmpeg avformat-ffmpeg avutil-ffmpeg swscale-ffmpeg /usr/lib/libOpenNI.so Qt5::Core Qt5::Gui Qt5::Widgets /usr/lib/x86_64-linux-gnu/hdf5/serial/lib/libhdf5.so /usr/lib/x86_64-linux-gnu/libpthread.so /usr/lib/x86_64-linux-gnu/libsz.so /usr/lib/x86_64-linux-gnu/libdl.so /usr/lib/x86_64-linux-gnu/libm.so vtkRenderingOpenGL vtkImagingHybrid vtkIOImage vtkCommonDataModel vtkCommonMath vtkCommonCore vtksys vtkCommonMisc vtkCommonSystem vtkCommonTransforms vtkCommonExecutionModel vtkDICOMParser vtkIOCore /usr/lib/x86_64-linux-gnu/libz.so vtkmetaio /usr/lib/x86_64-linux-gnu/libjpeg.so /usr/lib/x86_64-linux-gnu/libpng.so /usr/lib/x86_64-linux-gnu/libtiff.so vtkImagingCore vtkRenderingCore vtkCommonColor vtkFiltersExtraction vtkFiltersCore vtkFiltersGeneral vtkCommonComputationalGeometry vtkFiltersStatistics vtkImagingFourier vtkalglib vtkFiltersGeometry vtkFiltersSources vtkInteractionStyle vtkRenderingLOD vtkFiltersModeling vtkIOPLY vtkIOGeometry /usr/lib/x86_64-linux-gnu/libjsoncpp.so vtkFiltersTexture vtkRenderingFreeType /usr/lib/x86_64-linux-gnu/libfreetype.so vtkftgl vtkIOExport vtkRenderingAnnotation vtkImagingColor vtkRenderingContext2D vtkRenderingGL2PS vtkRenderingContextOpenGL /usr/lib/libgl2ps.so vtkRenderingLabel dl m pthread rt /usr/lib/x86_64-linux-gnu/libGLU.so /usr/lib/x86_64-linux-gnu/libGL.so tbb
3rdparty dependencies: libprotobuf
OpenCV modules:
To be built: core flann hdf imgproc ml photo reg surface_matching video viz dnn freetype fuzzy imgcodecs shape videoio highgui objdetect plot superres ts xobjdetect xphoto bgsegm bioinspired dpm face features2d line_descriptor saliency text calib3d ccalib cvv datasets rgbd stereo tracking videostab xfeatures2d ximgproc aruco optflow phase_unwrapping stitching structured_light python2
Disabled: world contrib_world
Disabled by dependency: -
Unavailable: cudaarithm cudabgsegm cudacodec cudafeatures2d cudafilters cudaimgproc cudalegacy cudaobjdetect cudaoptflow cudastereo cudawarping cudev java python3 cnn_3dobj matlab sfm
Non-free algorithms are enabled
GUI:
QT 5.x: YES (ver 5.5.1)
QT OpenGL support: YES (Qt5::OpenGL 5.5.1)
OpenGL support: YES (/usr/lib/x86_64-linux-gnu/libGLU.so /usr/lib/x86_64-linux-gnu/libGL.so)
VTK support: YES (ver 6.2.0)
Media I/O:
ZLib: /usr/lib/x86_64-linux-gnu/libz.so (ver 1.2.8)
JPEG: /usr/lib/x86_64-linux-gnu/libjpeg.so (ver )
WEBP: /usr/lib/x86_64-linux-gnu/libwebp.so (ver encoder: 0x0202)
PNG: /usr/lib/x86_64-linux-gnu/libpng.so (ver 1.2.54)
TIFF: /usr/lib/x86_64-linux-gnu/libtiff.so (ver 42 - 4.0.6)
JPEG 2000: /usr/lib/x86_64-linux-gnu/libjasper.so (ver 1.900.1)
OpenEXR: /usr/lib/x86_64-linux-gnu/libImath.so /usr/lib/x86_64-linux-gnu/libIlmImf.so /usr/lib/x86_64-linux-gnu/libIex.so /usr/lib/x86_64-linux-gnu/libHalf.so /usr/lib/x86_64-linux-gnu/libIlmThread.so (ver 2.2.0)
GDAL: NO
GDCM: NO
Video I/O:
DC1394 1.x: NO
DC1394 2.x: YES (ver 2.2.4)
FFMPEG: YES
avcodec: YES (ver 56.60.100)
avformat: YES (ver 56.40.101)
avutil: YES (ver 54.31.100)
swscale: YES (ver 3.1.101)
avresample: NO
GStreamer: NO
OpenNI: YES (ver 1.5.4, build 0)
OpenNI PrimeSensor Modules: NO
OpenNI2: NO
PvAPI: NO
GigEVisionSDK: NO
Aravis SDK: NO
UniCap: NO
UniCap ucil: NO
V4L/V4L2: NO/YES
XIMEA: NO
Xine: NO
gPhoto2: NO
Parallel framework: TBB (ver 4.4 interface 9002)
Other third-party libraries:
Use IPP: 9.0.1 [9.0.1]
at: /home/ronjane92/Programs/opencv/opencv-3.2.0-build/3rdparty/ippicv/ippicv_lnx
Use IPP Async: NO
Use VA: NO
Use Intel VA-API/OpenCL: NO
Use Lapack: NO
Use Eigen: YES (ver 3.2.92)
Use Cuda: NO
Use OpenCL: YES
Use OpenVX: NO
Use custom HAL: NO
OpenCL: <Dynamic loading of OpenCL library>
Include path: /home/ronjane92/Programs/opencv/opencv-3.2.0-source/3rdparty/include/opencl/1.2
Use AMDFFT: NO
Use AMDBLAS: NO
Python 2:
Interpreter: /usr/bin/python2.7 (ver 2.7.12)
Libraries: /usr/lib/x86_64-linux-gnu/libpython2.7.so (ver 2.7.12)
numpy: /home/ronjane92/.local/lib/python2.7/site-packages/numpy/core/include (ver 1.13.1)
packages path: lib/python2.7/dist-packages
Python 3:
Interpreter: /usr/bin/python3 (ver 3.5.2)
Python (for build): /usr/bin/python2.7
Java:
ant: NO
JNI: NO
Java wrappers: NO
Java tests: NO
Matlab: Matlab not found or implicitly disabled
Documentation:
Doxygen: /usr/bin/doxygen (ver 1.8.11)
Tests and samples:
Tests: YES
Performance tests: YES
C/C++ Examples: NO
Install path: /usr/local
cvconfig.h is in: /home/ronjane92/Programs/opencv/opencv-3.2.0-build
-----------------------------------------------------------------
Configuring done
Generating done
这是一个重复的问题，所以我试图谷歌寻求解决方案，但没有一个在我的情况下工作。谁可以帮助我？感谢。
答案 0 :(得分：2)
问题解决了。我定义了一些函数，这些函数需要链接到OpenCV库。但是，我只是将FIND_PACKAGE和INCLUDE_DIRECTORIES添加到源目录中的CMakeLists.txt中的OpenCV，但是放在标题和源所在的目录中。添加到lib目录后，一切都很顺利。
请参阅The solution