11 帧差法获取运动

帧差法

三帧差法

录频工具转gif

#include "core/core.hpp"
#include "highgui/highgui.hpp"
#include "imgproc/imgproc.hpp"

using namespace cv;

int main(int argc, char *argv[])
{
	VideoCapture videoCap(0);
	if (!videoCap.isOpened())
	{
		return -1;
	}
	double videoFPS = videoCap.get(CV_CAP_PROP_FPS);  //获取帧率
	double videoPause = 1000 / videoFPS;
	Mat framePrePre; //上上一帧
	Mat framePre; //上一帧
	Mat frameNow; //当前帧
	Mat frameDet; //运动物体
	videoCap >> framePrePre;
	videoCap >> framePre;
	cvtColor(framePrePre, framePrePre, CV_RGB2GRAY);
	cvtColor(framePre, framePre, CV_RGB2GRAY);
	int save = 0;
	while (true)
	{
		videoCap >> frameNow;
	//	if (frameNow.empty() || waitKey() == 27)
	if (frameNow.empty() )
		{
			break;
		}
		cvtColor(frameNow, frameNow, CV_RGB2GRAY);
		Mat Det1;
		Mat Det2;
		absdiff(framePrePre, framePre, Det1);  //帧差1
		absdiff(framePre, frameNow, Det2);     //帧差2
		threshold(Det1, Det1, 0, 255, CV_THRESH_OTSU);  //自适应阈值化
		threshold(Det2, Det2, 0, 255, CV_THRESH_OTSU);
		Mat element = getStructuringElement(0, Size(3, 3));  //膨胀核
		dilate(Det1, Det1, element);    //膨胀
		dilate(Det2, Det2, element);
		bitwise_and(Det1, Det2, frameDet);
		framePrePre = framePre;
		framePre = frameNow;
		imshow("Video", frameNow);
		imshow("Detection", frameDet);
		waitKey(1);
	}
	return 0;
}

　　

画正弦曲线

#include "core/core.hpp"
#include "highgui/highgui.hpp"
#include "imgproc/imgproc.hpp"
#include "opencv2/imgproc/imgproc.hpp" 
#include "opencv2/highgui/highgui.hpp" 
#include <stdlib.h> 
#include <stdio.h> 
#include <math.h> 
#include "opencv/cv.h" 
#include "opencv/highgui.h" 

using namespace cv;

int main(int argc, char *argv[])
{
	double y[400];
	float x;
	for (x = 0; x<400; x++)
	{
	//	y[(int)floor(x)] = sin(x);
		y[(int)floor(x)] = 200 + 100 * sin(x*0.2);

	}
	

	Mat grf(410, 410, CV_8UC3);// CV_8UC3  CV_32F

	for (int x = 0; x<400; x++)
	{
		line(grf,       /* the dest image */
			cvPoint(x, y[x]), /* start point */

			cvPoint(x + 1, y[x + 1]),   /* end point */
			Scalar(0, 255, 0),  /* the color; green */
			2, 4, 0);     /* thickness, line type, shift */

	}
	cvNamedWindow("img", CV_WINDOW_AUTOSIZE);
	imshow("img", grf);


	VideoCapture videoCap(0);
	if (!videoCap.isOpened())
	{
		return -1;
	}
	double videoFPS = videoCap.get(CV_CAP_PROP_FPS);  //获取帧率
	double videoPause = 1000 / videoFPS;
	Mat framePrePre; //上上一帧
	Mat framePre; //上一帧
	Mat frameNow; //当前帧
	Mat frameDet; //运动物体
	videoCap >> framePrePre;
	videoCap >> framePre;
	cvtColor(framePrePre, framePrePre, CV_RGB2GRAY);
	cvtColor(framePre, framePre, CV_RGB2GRAY);
	int save = 0;
	while (true)
	{
		videoCap >> frameNow;
	//	if (frameNow.empty() || waitKey() == 27)
	if (frameNow.empty() )
		{
			break;
		}
		cvtColor(frameNow, frameNow, CV_RGB2GRAY);
		Mat Det1;
		Mat Det2;
		absdiff(framePrePre, framePre, Det1);  //帧差1
		absdiff(framePre, frameNow, Det2);     //帧差2
		threshold(Det1, Det1, 0, 255, CV_THRESH_OTSU);  //自适应阈值化
		threshold(Det2, Det2, 0, 255, CV_THRESH_OTSU);
		Mat element = getStructuringElement(0, Size(9, 9));  //膨胀核
		dilate(Det1, Det1, element);   
		dilate(Det2, Det2, element);
		bitwise_and(Det1, Det2, frameDet);
		framePrePre = framePre;
		framePre = frameNow;



		imshow("Video", frameNow);

		cvtColor(frameDet, frameDet, CV_GRAY2RGB);
		for (int x = 0; x<400; x++)
		{
			line(frameDet,       /* the dest image */
				cvPoint(x, y[x]), /* start point */

				cvPoint(x + 1, y[x + 1]),   /* end point */
				Scalar(0, 255, 0),  /* the color; green */
				2, 4, 0);     /* thickness, line type, shift */

		}

		imshow("Detection", frameDet);
		waitKey(1);
	}
	return 0;
}