Opencv 2.4 compilation error with objectdetect.hpp - c++

Question

I have installed OpenCV using the instructions provided on the wiki using cmake. I have built the files on my desktop. The first program that I tried to run was a simple capture from camera program. Its source is
#include "cv.h"
#include "highgui.h"
#include <stdio.h>
int main() {
CvCapture* capture = cvCaptureFromCAM( CV_CAP_ANY );
if ( !capture ) {
fprintf( stderr, "ERROR: capture is NULL \n" );
getchar();
return -1;
}
cvNamedWindow( "mywindow", CV_WINDOW_AUTOSIZE );
while ( 1 ) {
IplImage* frame = cvQueryFrame( capture );
if ( !frame ) {
fprintf( stderr, "ERROR: frame is null...\n" );
getchar();
break;
}
cvShowImage( "Cam WIndow", frame );
if ( (cvWaitKey(10) & 255) == 27 ) break;
}
cvReleaseCapture( &capture );
cvDestroyWindow( "Cam WIndow" );
return 0;
}
It is compiling properly with the g++ command with pkg-config provided below:
g++ -o cam Camera.cpp pkg-config opencv --cflags --libs
The second program that I have tried to run is also fom there wiki, the face recognition program, its source is given below.
#include <opencv2/objdetect/objdetect.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
#include <stdio.h>
using namespace std;
using namespace cv;
void detectAndDisplay( Mat frame );
String face_cascade_name = "lbpcascade_frontalface.xml";
String eyes_cascade_name = "haarcascade_eye_tree_eyeglasses.xml";
CascadeClassifier face_cascade;
CascadeClassifier eyes_cascade;
string window_name = "Capture - Face detection";
RNG rng(12345);
int main( int argc, const char** argv )
{
CvCapture* capture;
Mat frame;
if( !face_cascade.load( face_cascade_name ))
{
printf("--(!)Error loading\n");
return -1;
};
if( !eyes_cascade.load( eyes_cascade_name ))
{
printf("--(!)Error loading\n");
return -1;
};
capture = cvCaptureFromCAM( -1 );
if( capture )
{
while( true )
{
frame = cvQueryFrame( capture );
if( !frame.empty() )
{ detectAndDisplay( frame ); }
else
{ printf(" --(!) No captured frame -- Break!"); break; }
int c = waitKey(10);
if( (char)c == 'c' ) { break; }
}
}
return 0;
}
void detectAndDisplay( Mat frame )
{
std::vector<Rect> faces;
Mat frame_gray;
cvtColor( frame, frame_gray, CV_BGR2GRAY );
equalizeHist( frame_gray, frame_gray );
face_cascade.detectMultiScale( frame_gray, faces, 1.1, 2, 0, Size(80, 80) );
for( int i = 0; i < faces.size(); i++ )
{
Mat faceROI = frame_gray( faces[i] );
std::vector<Rect> eyes;
eyes_cascade.detectMultiScale(faceROI,eyes,1.1,2,0|CV_HAAR_SCALE_IMAGE,Size(30, 30));
if( eyes.size() == 2)
{
Point center( faces[i].x + faces[i].width*0.5, faces[i].y + faces[i].height*0.5 );
ellipse(frame,center,Size(faces[i].width*0.5,faces[i].height*0.5),0,0,360,Scalar(255,0,0),2,8,0);
for( int j = 0; j < eyes.size(); j++ )
{ \
Point center( faces[i].x + eyes[j].x + eyes[j].width*0.5, faces[i].y + eyes[j].y + eyes[j].height*0.5 );
int radius = cvRound( (eyes[j].width + eyes[j].height)*0.25 );
circle( frame, center, radius, Scalar( 255, 0, 255 ), 3, 8, 0 );
}
}
}
imshow( window_name, frame );
}
Now this program I compiled using the command given below:
g++ -o cam Cam1.cpp -lopencv_core -lopencv_imgproc -lopencv_calib3d -lopencv_video -lopencv_features2d -lopencv_ml -lopencv_highgui -lopencv_objdetect -lopencv_contrib -lopencv_legacyD
This compilation command gives the error
fatal error: opencv2/objdetect/objdetect.hpp: No such file or directory
What to do?

Answer 1

The error is because of the compiler couldn't find the file "objdetect.hpp". There might be two reasons for that.
1)The file "objdetect.hpp" will be generated during the installation process of the opencv, so if there any problem at this step the file might haven't created, so first check for that file.
2)If you could find that file, then the problem will be due to the compiler couldn't get the path to the file, so you have to fix it. It can be done by either include the exact path to the list of included paths in the make file for the objectdetcet module using -I/path/to/the/file.
If you don't have such a make file then you can specify the path through command line using the above -I/ Option.
It can also be done in another way by exporting the path to some flag(I don't know the name of the flag),so that the compiler will look into that path exported , during the compile time,I am not sure about this method ,Please check it in internet.
Hope that you can fix the problem with this ..