C++ opencv2/nonfree/features2d.hpp没有这样的文件或目录

我正在尝试使用覆盆子皮冲浪。我得到了冠军。我找到了答案并安装了“libopencv-nonfree-dev”。在那之后，我得到了同样的错误。安装“libopencv nonfree dev”后有什么要做的吗

有人写下“将你的程序链接到-lopencv_nonfree，否则你无法访问冲浪。”

如果问题是这样的，我如何使用Cmake文件将其链接到我的程序

下面是错误：

g++ example.cpp -o example.o -c -Wall -I/usr/local/include/opencv -I/usr/local/include 
example.cpp:4:42: fatal error: opencv2/nonfree/features2d.hpp: No such file or directory
 #include <opencv2/nonfree/features2d.hpp>
                                          ^
compilation terminated.
Makefile:10: recipe for target 'example.o' failed
make: *** [example.o] Error 1

---

代码应该是文本（相应地格式化），而不是图像。错误消息也一样。@Tsyvarev我已修复它。如何将非自由库链接到我的程序？包

libopencv-nonfree-dev

是否实际提供了头文件opencv2/nonfree/features2d.hpp？如果是这样的话，那个标题的确切（绝对）路径是什么？@Tsyvarev我有那个文件opencv2/nonfree/features2d.hpp。我不知道如何检查“到该标题的确切（绝对）路径是什么？”。请引导me@Tsyvarev在“/home/pi/opencv-3.1.0/include/opencv2/nonfree”代码中，它应该是文本（相应地格式化），而不是图像。错误消息也一样。@Tsyvarev我已修复它。如何将非自由库链接到我的程序？包

libopencv-nonfree-dev

是否实际提供了头文件opencv2/nonfree/features2d.hpp？如果是这样的话，那个标题的确切（绝对）路径是什么？@Tsyvarev我有那个文件opencv2/nonfree/features2d.hpp。我不知道如何检查“到该标题的确切（绝对）路径是什么？”。请引导me@Tsyvarev它位于“/home/pi/opencv-3.1.0/include/opencv2/nonfree”中

# cmake needs this line
cmake_minimum_required(VERSION 2.8)

# Define project name
project(opencv_example_project)

# Find OpenCV, you may need to set OpenCV_DIR variable
# to the absolute path to the directory containing OpenCVConfig.cmake file
# via the command line or GUI
find_package(OpenCV REQUIRED)

# If the package has been found, several variables will
# be set, you can find the full list with descriptions
# in the OpenCVConfig.cmake file.
# Print some message showing some of them
message(STATUS "OpenCV library status:")
message(STATUS "    version: ${OpenCV_VERSION}")
message(STATUS "    libraries: ${OpenCV_LIBS}")
message(STATUS "    include path: ${OpenCV_INCLUDE_DIRS}")

if(CMAKE_VERSION VERSION_LESS "2.8.11")
  # Add OpenCV headers location to your include paths
  include_directories(${OpenCV_INCLUDE_DIRS})
endif()

# Declare the executable target built from your sources
add_executable(opencv_example example.cpp)

# Link your application with OpenCV libraries
target_link_libraries(opencv_example ${OpenCV_LIBS})