在此范围内未声明faceRecognizer。

Question

我使用了2.4.7版本的opencv，它支持人脸识别。但是，我收到以下错误：

 /home/fereres/recognition-build-desktop- Qt_4_8_1_in_PATH__System__Release/../recognition/program.cpp:58: error: 'FaceRecognizer' was  not declared in this scope  

编辑:程序正在工作，因为我刚刚换了电脑。我按照相同的说明安装了OpenCV。是什么造成了这个错误？？我的QT文件如下：

       QT       += core
       QT       -= gui

      TARGET = identification
      CONFIG   += console/home/fereres/projectCV-build-desktop-        Qt_4_8_1_in_PATH__System__Release
      CONFIG   -= app_bundle

      TEMPLATE = app

      INCLUDEPATH += /home/fereres/Desktop/OpenCV/opencv-2.4.7/include/opencv \
      INCLUDEPATH += /home/fereres/Desktop/OpenCV/opencv-2.4.7/include/opencv2 \
      INCLUDEPATH +=  /home/fereres/Desktop/OpenCV/opencv-2.4.7/modules/core/include/opencv2/core

      LIBS += -L/home/fereres/Desktop/OpenCV/opencv-2.4.7/build/lib \
       -lopencv_core \
       -lopencv_imgproc \
       -lopencv_highgui \
       -lopencv_ml \
       -lopencv_video \
       -lopencv_features2d \
       -lopencv_calib3d \
       -lopencv_objdetect \
       -lopencv_contrib \
       -lopencv_legacy \
       -lopencv_flann

       SOURCES += \
          program.cpp \
          prediction.cpp \
          Detection.cpp

      HEADERS += \
          prediction.h \
          Detection.h 

编译结果没有错误。然而，当我运行我的应用程序时，我得到了

 ./identification: error while loading shared libraries: libopencv_core.so.2.4: cannot  open shared object file: No such file or directory
  fereres@ubuntu:~/identification-build-desktop-Qt_4_8_1_in_PATH__System__Release$ 

/usr/local/lib forlder只包含一个python文件夹，我无法在那里找到我的库。

EDIT2:我又安装了opencv，现在一切都很好。我想安装opencv的最后一步不起作用，所以我的/usr/local文件夹是空的。现在一切都在控制之中。

Answer 1

最好将INCLUDEPATH初始化调整为以下内容，否则在路径开头引用opencv2的每个#include语句都会导致编译错误：

INCLUDEPATH += "/home/fereres/Desktop/OpenCV/opencv-2.4.7/include" \
               "/home/fereres/Desktop/OpenCV/opencv-2.4.7/include/opencv" \
               "/home/fereres/Desktop/OpenCV/opencv-2.4.7/include/opencv2" \
               "/home/fereres/Desktop/OpenCV/opencv-2.4.7/modules/core/include/opencv2/core"

然后，在recognition/program.cpp，不要忘记包含适当的头文件：

#include <opencv2/contrib/contrib.hpp>

opencv_contrib备注：由于您使用pkg-config来添加所有OpenCV库，所以不需要这样做，但是对于那些单独指定库的人，您需要将添加到LIBS中。