使用 OpenCV 进行运动检测

    import numpy as np
    import cv2
    
    sdThresh = 10
    font = cv2.FONT_HERSHEY_SIMPLEX
    
    def distMap(frame1, frame2):
    """outputs pythagorean distance between two frames"""
    frame1_32 = np.float32(frame1)
    frame2_32 = np.float32(frame2)
    diff32 = frame1_32 - frame2_32
    norm32 = np.sqrt(diff32[:,:,0]**2 + diff32[:,:,1]**2 + \
             diff32[:,:,2]**2)/np.sqrt(255**2 + 255**2 + 255**2)
    dist = np.uint8(norm32*255)
    return dist
    
    cv2.namedWindow('frame')
    cv2.namedWindow('dist')
    
    #capture video stream from camera source. 0 refers to first camera, 1 referes to 2nd and so on.
    cap = cv2.VideoCapture(0)
    
    _, frame1 = cap.read()
    _, frame2 = cap.read()
    
    facecount = 0
    while(True):
    _, frame3 = cap.read()
    rows, cols, _ = np.shape(frame3)
    cv2.imshow('dist', frame3)
    dist = distMap(frame1, frame3)
    
    frame1 = frame2
    frame2 = frame3
    
    # apply Gaussian smoothing
    mod = cv2.GaussianBlur(dist, (9,9), 0)
    
    # apply thresholding
    _, thresh = cv2.threshold(mod, 100, 255, 0)
    
    # calculate st dev test
    _, stDev = cv2.meanStdDev(mod)
    
    cv2.imshow('dist', mod)
    cv2.putText(frame2, "Standard Deviation - {}".format(round(stDev[0][0],0)), \
                (70, 70), font, 1, (255, 0, 255), 1, cv2.LINE_AA)
    if stDev > sdThresh:
            print("Motion detected.. Do something!!!");
    
    cv2.imshow('frame', frame2)
    if cv2.waitKey(1) & 0xFF == 27:
        break
    
    cap.release()
    cv2.destroyAllWindows()

    g++ motion.cpp -o motion `pkg-config --cflags --libs opencv`

    #include <opencv2/core/core.hpp>
    #include <opencv2/highgui/highgui.hpp>
    #include <opencv2/imgproc/imgproc.hpp>
    #include <cstdio>
    #include <cmath>
    #include <cstdlib>
    #include"omp.h"
    
    using namespace cv;
    #define MOTION_THRESH 10
    
    void distMap(const Mat &a, const Mat &b, Mat &out){
    #pragma omp parallel
    for(int y = 0; y < a.rows; ++y){
        for(int x = 0; x < a.cols; ++x){
            int summary = 0;
            for(int z = 0; z < a.dims; ++z){
                summary += pow(a.at<Vec3b>(y, x)[z] - b.at<Vec3b>(y, x)[z], 2);
            }
            out.at<uchar>(y, x) = (int) (255.0 * sqrt(summary) / sqrt(3 * pow(255, 2)));
        }
    }
    }
    
    
    int main(int argc, char **argv){
    printf("=========== initializing ==========\n");
    
    int device = 0;
    int motion_count = 0;
    
    if(argc == 2) {
        device = atoi(argv[1]);
    }
    
    printf("device id %d\n", device);
    
    VideoCapture myCamera(device);
    
    myCamera.set(CV_CAP_PROP_FRAME_WIDTH, 640);
    myCamera.set(CV_CAP_PROP_FRAME_HEIGHT, 480);
    
    if (!myCamera.isOpened()){
        printf("cannot open camera\n");
        return 0;
    }else{
        printf("%s\n", "===========start camera==========");
    }
    
    Mat preVideoFrame, curVideoFrame, nextVideoFrame;
    
    for(int i = 0; i < 5; i++) {
        myCamera >> preVideoFrame;
    }
    
    myCamera >> preVideoFrame;
    myCamera >> curVideoFrame;
    
    
    Mat dist(preVideoFrame.rows, preVideoFrame.cols, CV_8UC1);
    Mat blurDist(preVideoFrame.rows, preVideoFrame.cols, CV_8UC1);
    Mat threDist(preVideoFrame.rows, preVideoFrame.cols, CV_8UC1);
    Mat meanDist(preVideoFrame.rows, preVideoFrame.cols, CV_8UC1);
    Mat stdDist(1, 1, CV_8UC1);
    
    char text[100] = {0};
    
    int key = 0;
    while (key != 27){
        myCamera >> nextVideoFrame;
    
        // key = waitKey(1);
        // continue;
    
        if (!preVideoFrame.empty() && !curVideoFrame.empty() && !nextVideoFrame.empty()){
            distMap(preVideoFrame, nextVideoFrame, dist);
    
            curVideoFrame.copyTo(preVideoFrame);
            nextVideoFrame.copyTo(curVideoFrame);
    
            blur(dist, blurDist, Size(3, 3));
    
            threshold(blurDist, threDist, 100, 255, THRESH_BINARY);
    
            meanStdDev(threDist, meanDist, stdDist);
    
            sprintf(text, "Standard Deviation - %d", stdDist.at<uchar>(0, 0));
    
            cv::putText(curVideoFrame, text, Point(70, 70), FONT_HERSHEY_SIMPLEX, 
                        1, (255, 0, 255), 1, LINE_AA);
    
            if(stdDist.at<uchar>(0, 0) > MOTION_THRESH) {
                printf("%d motion detected\r", stdDist.at<uchar>(0, 0));
                fflush(stdout);
            }
    
            imshow("distMap", blurDist);
            imshow("preview", curVideoFrame);
    
        }
    
        key = waitKey(1);
    }
    
    myCamera.release();
    printf("%s\n", "===========release camera==========");
    
    return 0;
    }