OpenCV對象檢測教程

Question

我是OpenCV平臺的新手。我已經安裝併成功運行了一些教程代碼（內置）。但是，我正在面對涉及hacascascade的代碼的一些問題。代碼完美地構建，並且網絡攝像頭似乎閃爍並且工作，但是代碼顯示附加的空白窗口。 image

任何人都可以提出一些整改的問題？

（我使用OpenCV的版本3.0.0和視覺工作室2013年）

#include "stdafx.h" 
    #include "opencv2/objdetect.hpp" 
    #include "opencv2/videoio.hpp" 
    #include "opencv2/highgui.hpp" 
    #include "opencv2/imgproc.hpp" 

    #include <iostream> 
    #include <stdio.h> 
    using namespace std; 
    using namespace cv; 

    /** Function Headers */ 
    void detectAndDisplay(Mat frame); 

    /** Global variables */ 
    String face_cascade_name = "haarcascade_frontalface_alt.xml"; 
    String eyes_cascade_name = "haarcascade_eye_tree_eyeglasses.xml"; 
    CascadeClassifier face_cascade; 
    CascadeClassifier eyes_cascade; 
    String window_name = "Capture - Face detection"; 

    /** @function main */ 
    int main(void) 
    { 
    VideoCapture capture; 
Mat frame; 

//-- 1. Load the cascades 
if(!face_cascade.load(face_cascade_name)){ printf("--(!)Error loading face cascade\n"); return -1; }; 
if(!eyes_cascade.load(eyes_cascade_name)){ printf("--(!)Error loading eyes cascade\n"); return -1; }; 

//-- 2. Read the video stream 
capture.open(-1); 
if (! capture.isOpened()) { printf("--(!)Error opening video capture\n"); return -1; } 

while (capture.read(frame)) 
{ 
    if(frame.empty()) 
    { 
     printf(" --(!) No captured frame -- Break!"); 
     break; 
    } 

    //-- 3. Apply the classifier to the frame 
    detectAndDisplay(frame); 

    int c = waitKey(10); 
    if((char)c == 27) { break; } // escape 
} 
return 0; 
    } 

    /** @function detectAndDisplay */ 
    void detectAndDisplay(Mat frame) 
    { 
     std::vector<Rect> faces; 
Mat frame_gray; 

cvtColor(frame, frame_gray, COLOR_BGR2GRAY); 
equalizeHist(frame_gray, frame_gray); 

//-- Detect faces 
face_cascade.detectMultiScale(frame_gray, faces, 1.1, 2, 0|CASCADE_SCALE_IMAGE, Size(30, 30)); 

for (size_t i = 0; i < faces.size(); i++) 
{ 
    Point center(faces[i].x + faces[i].width/2, faces[i].y + faces[i].height/2); 
    ellipse(frame, center, Size(faces[i].width/2, faces[i].height/2), 0, 0, 360, Scalar(255, 0, 255), 4, 8, 0); 

    Mat faceROI = frame_gray(faces[i]); 
    std::vector<Rect> eyes; 

    //-- In each face, detect eyes 
    eyes_cascade.detectMultiScale(faceROI, eyes, 1.1, 2, 0 |CASCADE_SCALE_IMAGE, Size(30, 30)); 

    for (size_t j = 0; j < eyes.size(); j++) 
    { 
     Point eye_center(faces[i].x + eyes[j].x + eyes[j].width/2, faces[i].y + eyes[j].y + eyes[j].height/2); 
     int radius = cvRound((eyes[j].width + eyes[j].height)*0.25); 
     circle(frame, eye_center, radius, Scalar(255, 0, 0), 4, 8, 0); 
    } 
} 
//-- Show what you got 
imshow(window_name, frame); 
    } 

Answer 1

我認爲這是a known bug

可以嘗試我更新的代碼（我所指出的意見修改）

#include "opencv2/objdetect.hpp" 
#include "opencv2/videoio.hpp" 
#include "opencv2/highgui.hpp" 
#include "opencv2/imgproc.hpp" 
#include <opencv2/core/ocl.hpp> // additional header ************************ 

#include <iostream> 
#include <stdio.h> 

using namespace std; 
using namespace cv; 

/** Function Headers */ 
void detectAndDisplay(Mat frame); 

/** Global variables */ 
String face_cascade_name = "haarcascade_frontalface_alt.xml"; 
String eyes_cascade_name = "haarcascade_eye_tree_eyeglasses.xml"; 
CascadeClassifier face_cascade; 
CascadeClassifier eyes_cascade; 
String window_name = "Capture - Face detection"; 

/** @function main */ 
int main(void) 
{ 
    ocl::setUseOpenCL(false); // disable OpenCL ******************* 
    VideoCapture capture; 
    Mat frame; 

    //-- 1. Load the cascades 
    if(!face_cascade.load(face_cascade_name)){ printf("--(!)Error loading face cascade\n"); return -1; }; 
    if(!eyes_cascade.load(eyes_cascade_name)){ printf("--(!)Error loading eyes cascade\n"); return -1; }; 

    //-- 2. Read the video stream 
    capture.open(0); // Open webcam 0 *************************** 
    if (! capture.isOpened()) { printf("--(!)Error opening video capture\n"); return -1; } 

    while (capture.read(frame)) 
    { 
     if(frame.empty()) 
     { 
      printf(" --(!) No captured frame -- Break!"); 
      break; 
     } 

     //-- 3. Apply the classifier to the frame 
     detectAndDisplay(frame); 

     int c = waitKey(10); 
     if((char)c == 27) { break; } // escape 
    } 
    return 0; 
} 

/** @function detectAndDisplay */ 
void detectAndDisplay(Mat frame) 
{ 
    std::vector<Rect> faces; 
    Mat frame_gray; 

    cvtColor(frame, frame_gray, COLOR_BGR2GRAY); 
    equalizeHist(frame_gray, frame_gray); 

    //-- Detect faces 
    face_cascade.detectMultiScale(frame_gray, faces, 1.1, 2, 0|CASCADE_SCALE_IMAGE, Size(30, 30)); 

    for (size_t i = 0; i < faces.size(); i++) 
    { 
     Point center(faces[i].x + faces[i].width/2, faces[i].y + faces[i].height/2); 
     ellipse(frame, center, Size(faces[i].width/2, faces[i].height/2), 0, 0, 360, Scalar(255, 0, 255), 4, 8, 0); 

     Mat faceROI = frame_gray(faces[i]); 
     std::vector<Rect> eyes; 

     //-- In each face, detect eyes 
     eyes_cascade.detectMultiScale(faceROI, eyes, 1.1, 2, 0 |CASCADE_SCALE_IMAGE, Size(30, 30)); 

     for (size_t j = 0; j < eyes.size(); j++) 
     { 
      Point eye_center(faces[i].x + eyes[j].x + eyes[j].width/2, faces[i].y + eyes[j].y + eyes[j].height/2); 
      int radius = cvRound((eyes[j].width + eyes[j].height)*0.25); 
      circle(frame, eye_center, radius, Scalar(255, 0, 0), 4, 8, 0); 
     } 
    } 
    //-- Show what you got 
    imshow(window_name, frame); 
}