/*

$ sudo yum install opencv-devel

Compile with:

$ gcc -o facedetect facedetect.c -I /usr/include/opencv   -lopencv_core -lopencv_imgproc -lopencv_video -lopencv_highgui -lopencv_objdetect

Simple test loop:

$ while :; do ./facedetect 2>/dev/null; sleep 1;done

*/

// OpenCV Sample Application: facedetect.c

// Include header files
#include "cv.h"
#include "highgui.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <math.h>
#include <float.h>
#include <limits.h>
#include <time.h>
#include <ctype.h>

// Main function, defines the entry point for the program.
int main( int argc, char** argv )
{
        int try=0; int has_faces=0;


        // Create memory for calculations
        static CvMemStorage* storage = 0;

        // Create a new Haar classifier
        static CvHaarClassifierCascade* cascade = 0;

        // Structure for getting video from camera or avi
        CvCapture* capture = 0;

        // Images to capture the frame from video or camera or from file
        IplImage *frame, *frame_copy = 0;

        // Load the HaarClassifierCascade
        cascade = (CvHaarClassifierCascade*)cvLoad( "/usr/share/OpenCV/haarcascades/haarcascade_eye_tree_eyeglasses.xml", 0, 0, 0 );

        // Check whether the cascade has loaded successfully. Else report and error and quit
        if( !cascade ) {
                fprintf( stderr, "ERROR: Could not load classifier cascade /usr/share/OpenCV/haarcascades/haarcascade_eye_tree_eyeglasses.xml\n" );
                return -1;
        }

        // Allocate the memory storage
        storage = cvCreateMemStorage(0);

        capture = cvCaptureFromCAM( 0 );

        // Find if the capture is loaded successfully or not.

        // If loaded succesfully, then:
        if( capture ) {
                // Capture from the camera.
                for(has_faces, try=0; (has_faces < 10) && (try < 30); try++)  {
                        // Capture the frame and load it in IplImage
                        if( !cvGrabFrame( capture ))
                                break;

                        frame = cvRetrieveFrame( capture, 0);

                        // If the frame does not exist, quit the loop
                        if( !frame )
                                continue;

                        // Allocate framecopy as the same size of the frame
                        if( !frame_copy )
                                frame_copy = cvCreateImage( cvSize(frame->width,frame->height),
                                                            IPL_DEPTH_8U, frame->nChannels );

                        // Check the origin of image. If top left, copy the image frame to frame_copy.
                        if( frame->origin == IPL_ORIGIN_TL )
                                cvCopy( frame, frame_copy, 0 );
                        // Else flip and copy the image
                        else
                                cvFlip( frame, frame_copy, 0 );

                        cvClearMemStorage( storage );

                        // Detect the objects and store them in the sequence
                        CvSeq* faces = cvHaarDetectObjects( frame_copy, cascade, storage,
                                                            1.2, 3, CV_HAAR_DO_CANNY_PRUNING,
                                                            cvSize(40, 40), cvSize(40, 40) );

                        if ( faces )
                                has_faces+=faces->total;
                }
        }
        cvReleaseCapture( &capture );

        if (has_faces)
                printf("Eyes detected\n");
        else
                printf("No eyes detected\n");

        return (has_faces == 0);
}