ตัวอย่างนี้แสดงถึงวิธีการใช้คำสั่งของ OpenCV เพื่อทำ edge detection โดยใช้วิธีของ Canny
#includeusing namespace std; #include #include #include #define CAMERA_ID 0 #define ORG_IMAGE_DISPLAY "original image" #define PROCESSED_IMAGE_DISPLAY "processed image" #define STRONG_EDGE_TH 100 #define WEAK_EDGE_TH 10 int main( int argc, char **argv ) { // create camera capture object. CvCapture *pCapture = NULL; pCapture = cvCreateCameraCapture( CAMERA_ID ); if ( pCapture == NULL ) { cout << "ERROR: Failed to open camera" << endl; return EXIT_FAILURE; } // create windows for displaying the captured image // and the captured image. cvNamedWindow( ORG_IMAGE_DISPLAY ); cvNamedWindow( PROCESSED_IMAGE_DISPLAY ); // capture, process, and display // until user hit any key of the keyboard IplImage *pOrgImage = NULL; IplImage *pProcessedImage = NULL; do { // release old image // before creating a new one if ( pProcessedImage != NULL ) { cvReleaseImage( &pProcessedImage ); pProcessedImage = NULL; } // capture new image pOrgImage = cvQueryFrame( pCapture ); // create image which has the same width, height, depth, and number of channels // as the original image for put the result of processing. pProcessedImage = cvCreateImage( cvSize( pOrgImage->width, pOrgImage->height ), pOrgImage->depth, 1 ); // do canny edge dectection cvCvtColor( pOrgImage, pProcessedImage, CV_BGR2GRAY ); cvCanny( pProcessedImage, pProcessedImage, STRONG_EDGE_TH, WEAK_EDGE_TH ); // display images cvShowImage( ORG_IMAGE_DISPLAY, pOrgImage ); cvShowImage( PROCESSED_IMAGE_DISPLAY, pProcessedImage ); } while ( cvWaitKey( 1 ) == -1 ); // release old image if ( pProcessedImage != NULL ) { cvReleaseImage( &pProcessedImage ); pProcessedImage = NULL; } // before exiting the program, // destroy the display windows and // release the cameara capture object. cvDestroyWindow( ORG_IMAGE_DISPLAY ); cvDestroyWindow( PROCESSED_IMAGE_DISPLAY ); cvReleaseCapture( &pCapture ); return 0; }
