OpenCV 基于CAMShift算法的对象检测与跟踪

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/u012841922/article/details/87824125

视频来源：http://edu.51cto.com/course/8837.html?source=so

以下代码用OpenCV实现了视频中基于CAMShift算法的对象检测与跟踪，该方法实质上仍然是基于色彩的对象跟踪，不过是在HSV色彩空间，选取Hue通道，一定程度上降低了光照变化所造成的影响。

//
//  main.cpp
//  opencv-learning
//
//  Created by _R on 2019/1/9.
//  Copyright © 2019 _R. All rights reserved.
//

#include <iostream>
#include <opencv2/opencv.hpp>

using namespace std;
using namespace cv;


int main(int argc, char* argv[])
{
    VideoCapture video = VideoCapture("/Users/_R/Desktop/video_006.mp4");
    if (!video.isOpened()) {
        cout << "could not load video file ..." << endl;
        return -1;
    }
    
    Mat frame, frame_hsv, frame_hsv_mask, ROI_image, ROI_image_hsv, ROI_image_mask, ROI_hist, backProjection;
    Mat ROI_hist_image = Mat::zeros(300, 300, CV_8UC3);
    Rect ROI_rect;
    
    const int channels[] = {0};
    const int bins = 8;
    int bin_width = ROI_hist_image.cols / bins;
    float hrange[] = {0,180};
    const float *ranges[] = {hrange};
    
    const string text_pause_ROI = "Press SPACE button to pause and select a ROI!";
    const string text_ROI_continue = "Please select a ROI and then press ENTER & SPACE button to continue!";
    
    namedWindow("ROI", WINDOW_AUTOSIZE);
    namedWindow("ROI Histogram", WINDOW_AUTOSIZE);
    namedWindow("Frame BackProjection", WINDOW_AUTOSIZE);
    namedWindow("CAMShift Tracking", WINDOW_AUTOSIZE);
    
    int vmin = 10;
    int smin = 100;
    int vmax = 256;
    createTrackbar("Vmin", "CAMShift Tracking", &vmin, 256);
    createTrackbar("Smin", "CAMShift Tracking", &smin, 256);
    createTrackbar("Vmax", "CAMShift Tracking", &vmax, 256);
    
    while (video.read(frame)) {
        char key_striked = waitKey(50);
        cvtColor(frame, frame_hsv, COLOR_BGR2HSV);
        inRange(frame_hsv, Scalar(0,smin,vmin), Scalar(180,256,vmax), frame_hsv_mask);
        
        // puase video
        if (key_striked == 32) {
            
            // ROI not selected
            if (ROI_rect.empty()) {
                putText(frame, text_ROI_continue, Point(20,20), FONT_ITALIC, 0.5, Scalar(0,0,255), 1, LINE_AA);
                ROI_rect = selectROI("CAMShift Tracking", frame);
                ROI_image = Mat(frame, ROI_rect);
                imshow("ROI", ROI_image);
                
                ROI_image_hsv = frame_hsv(ROI_rect);
                ROI_image_mask = frame_hsv_mask(ROI_rect);
                
                calcHist(&ROI_image_hsv, 1, channels, ROI_image_mask, ROI_hist, 1, &bins, ranges);
                normalize(ROI_hist, ROI_hist, 0, 300, NORM_MINMAX);
                
                for (int i = 0; i < bins; i++) {
                    rectangle(ROI_hist_image, Point(i*bin_width, ROI_hist_image.rows), Point((i+1)*bin_width, ROI_hist_image.rows - saturate_cast<int>(ROI_hist.at<float>(i))), Scalar(i*255/bins, 255 - i*255/bins, 255), -1);
                }
                imshow("ROI Histogram", ROI_hist_image);
            }
            
            char key_striked_while_paused = waitKey(0);
            if (key_striked_while_paused == 32) {
                continue;
            } else if (key_striked_while_paused == 27) {
                video.release();
                return 0;
            }
            
        // close window
        } else if (key_striked == 27) {
            video.release();
            return 0;
        }
        
        if (ROI_rect.empty()) {
            putText(frame, text_pause_ROI, Point(20,20), FONT_ITALIC, 0.5, Scalar(0,0,255), 1, LINE_AA);
        }
        
        // ROI selected
        if (!ROI_rect.empty()) {
            calcBackProject(&frame_hsv, 1, channels, ROI_hist, backProjection, ranges);
            backProjection &= frame_hsv_mask;
            imshow("Frame BackProjection", backProjection);
            
            RotatedRect tracking_rect = CamShift(backProjection, ROI_rect, TermCriteria((TermCriteria::COUNT | TermCriteria::EPS), 10, 1));
            
            ellipse(frame, tracking_rect, Scalar(0,0,255), 1, LINE_AA);
        }
        
        imshow("CAMShift Tracking", frame);
        
    }
    
    waitKey(0);
    video.release();
    return 0;
}

效果展示