cmake 配置参考见以下文章
https://wiki.qt.io/How_to_setup_Qt_and_openCV_on_Windows
https://blog.huihut.com/2017/12/03/CompiledOpenCVRunInQt/
编译过程中遇到的问题：
1.CMP0083 PIE policy warnings for executables are noisy
这个问题主要是因为cmake版本问题，cmake 3.14会有这个问题，详情https://gitlab.kitware.com/cmake/cmake/issues/18955。
切换成最新版的cmake 3.15解决。https://cmake.org/files/v3.15/
2.‘D3D11_TEXTURE2D_DESC’ was not declared in this scope 错误
在cmake config 中可以关闭 WITH_OPENCL_D3D11_NV 这个选项（默认是开的），然后重新 Configure-Generate-mingw32-make。
参考https://blog.csdn.net/huihut/article/details/81317102 第五点。
3.file not recognized,recipe for target failed
有两种情况：
第一种情况：Python2版成功，Python3版失败
第二种情况：只有Python3，仍然失败
先取消选中 Build_opencv_python3，后面用到再重新configure
参考：（这篇文章概括的比较全面，强烈推荐）
https://blog.csdn.net/yl_best/article/details/89190142#Issue%237%3APython3%E7%89%88%E7%BC%96%E8%AF%91%E5%A4%B1%E8%B4%A5
4.CMake Error: CMake was unable to find a build program corresponding to "MinGW Makefiles". CMAKE_MAK
CMake Error: CMake was unable to find a build program corresponding to "MinGW Makefiles". CMAKE_MAKE_PROGRAM is not set. You probably need to select a different build tool.
将CMAKE_MAKE_PROGRAM项后面的路径设置为Qt安装路径下的路径如下所示：MinGW/bin/mingw32-make.exe，重新点击Configure，问题解决！
参考：https://www.cnblogs.com/neo3301/p/13169841.html