如何构建 opencv 示例答案

【问题标题】：How to build opencv samples如何构建 opencv 示例
【发布时间】：2020-04-10 19:42:19
【问题描述】：

我是 cmake 的新手，虽然不是 make。这个问题与Could not build OpenCV Android sample project 不同，因为另一个问题是关于单个项目的，而这个问题正在查看overall CMakeLists.txt。

说到这：考虑${OPENCVDIR}/samples中的CMakeLists.txt：

我遵循cmake的基本流程：

cd  "${OPENCVDIR}/samples"
mkdir build
cd build
cmake ..

但在最后一步我有：

$ cmake ..
CMake Error at CMakeLists.txt:72 (find_package):
  Could not find a package configuration file provided by "OpenCV" with any
  of the following names:

    OpenCVConfig.cmake
    opencv-config.cmake

  Add the installation prefix of "OpenCV" to CMAKE_PREFIX_PATH or set
  "OpenCV_DIR" to a directory containing one of the above files.  If "OpenCV"
  provides a separate development package or SDK, be sure it has been
  installed.


-- Configuring incomplete, errors occurred!
See also "/git/opencv/samples/CMakeFiles/CMakeOutput.log".

第 72 行有这个：find_package(OpenCV REQUIRED PATHS "..")

我查看了错误日志，但没有提供任何信息。

Compilation of the CXX compiler identification source "CMakeCXXCompilerId.cpp" produced "a.out"

The CXX compiler identification is GNU, found in "/git/opencv/samples/CMakeFiles/3.13.4/CompilerIdCXX/a.out"

Determining if the C compiler works passed with the following output:
Change Dir: /git/opencv/samples/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_26f76/fast"
/usr/bin/make -f CMakeFiles/cmTC_26f76.dir/build.make CMakeFiles/cmTC_26f76.dir/build
make[1]: Entering directory '/git/opencv/samples/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_26f76.dir/testCCompiler.c.o
/usr/bin/cc    -o CMakeFiles/cmTC_26f76.dir/testCCompiler.c.o   -c /git/opencv/samples/CMakeFiles/CMakeTmp/testCCompiler.c
Linking C executable cmTC_26f76
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_26f76.dir/link.txt --verbose=1
/usr/bin/cc      -rdynamic CMakeFiles/cmTC_26f76.dir/testCCompiler.c.o  -o cmTC_26f76
make[1]: Leaving directory '/git/opencv/samples/CMakeFiles/CMakeTmp'


Detecting C compiler ABI info compiled with the following output:
"/git/opencv/samples/CMakeFiles/CMakeOutput.log" 706 lines, 48095 characters
    Feature record: CXX_FEATURE:0cxx_defaulted_move_initializers
    Feature record: CXX_FEATURE:0cxx_delegating_constructors
    Feature record: CXX_FEATURE:0cxx_deleted_functions
    Feature record: CXX_FEATURE:0cxx_digit_separators
    Feature record: CXX_FEATURE:0cxx_enum_forward_declarations
    Feature record: CXX_FEATURE:0cxx_explicit_conversions
    Feature record: CXX_FEATURE:0cxx_extended_friend_declar
   etc ..

构建这些示例的正确方法是什么 - 希望使用已经提供的 CMakeLists.txt？

【问题讨论】：

标签： opencv cmake

【解决方案1】：

cmake似乎找不到OpenCV的安装目录。尝试通过参数提供值：

cmake -DCMAKE_PREFIX_PATH=/home/someone/src/opencv/install ..

如果它有效，您可以在顶级 CMakeLitst.txt 中定义它：

list(APPEND CMAKE_PREFIX_PATH /home/someone/src/opencv/install)

这应该为 CMake 提供它应该寻找的地方。

【讨论】：