基于ROI的目标检测

 可用版：

#include "core/core.hpp"  
#include "highgui/highgui.hpp"  
#include "imgproc/imgproc.hpp"  
#include<iostream>  

using namespace cv;
using namespace std;

Mat frame;
Mat frameCopy; //绘制矩形框时用来拷贝原图的图像
bool leftButtonDownFlag = false; //左键单击后视频暂停播放的标志位
Point originalPoint; //矩形框起点
Point processPoint; //矩形框终点

//*******************************************************************//  
//鼠标回调函数  
void onMouse(int event, int x, int y, int flags, void *ustc)
{

	if (event == CV_EVENT_LBUTTONDOWN)
	{
		leftButtonDownFlag = true; //标志位
		originalPoint = Point(x, y);  //设置左键按下点的矩形起点
		processPoint = originalPoint;
	}
	if (event == CV_EVENT_MOUSEMOVE&&leftButtonDownFlag)
	{
		frameCopy = frame.clone();
		processPoint = Point(x, y);
		if (originalPoint != processPoint)
		{
			//在复制的图像上绘制矩形
			rectangle(frameCopy, originalPoint, processPoint, Scalar(255, 0, 0), 2);
		}
		imshow("Cap", frameCopy);
	}
	if (event == CV_EVENT_LBUTTONUP)
	{
		leftButtonDownFlag = false;
		Mat rectImage = frame(Rect(originalPoint, processPoint)); //子图像显示
		imshow("ROI", rectImage);
	}

}

Mat MoveDetect(Mat background, Mat img)
{
	//将background和img转为灰度图
	Mat result = img.clone();
	Mat gray1, gray2;
	cvtColor(background, gray1, CV_BGR2GRAY);
	cvtColor(img, gray2, CV_BGR2GRAY);

	//进行canny边缘检测 
	Canny(background, background, 0, 30, 3);

	//将background和img做差；对差值图diff进行阈值化处理
	Mat diff;
	absdiff(gray1, gray2, diff);
	//imshow("absdiss", diff);
	threshold(diff, diff, 50, 255, CV_THRESH_BINARY);
	//imshow("threshold", diff);

	/*
	//腐蚀膨胀消除噪音
	Mat element = getStructuringElement(MORPH_RECT, Size(3, 3));
	Mat element2 = getStructuringElement(MORPH_RECT, Size(15, 15));
	erode(diff, diff, element);
	//imshow("erode", diff);
	dilate(diff, diff, element2);
	//imshow("dilate", diff);
	*/

	//二值化后使用中值滤波+膨胀
	Mat element = getStructuringElement(MORPH_RECT, Size(11, 11));
	medianBlur(diff, diff, 5);//中值滤波
	//imshow("medianBlur", diff);
	dilate(diff, diff, element);
	//blur(diff, diff, Size(10, 10)); //均值滤波
	//imshow("dilate", diff);

	//查找并绘制轮廓
	vector<vector<Point>> contours;
	vector<Vec4i> hierarcy;
	findContours(diff, contours, hierarcy, CV_RETR_EXTERNAL, CHAIN_APPROX_NONE); //查找轮廓
	vector<Rect> boundRect(contours.size()); //定义外接矩形集合
	//drawContours(img2, contours, -1, Scalar(0, 0, 255), 1, 8);  //绘制轮廓

	//查找正外接矩形
	int x0 = 0, y0 = 0, w0 = 0, h0 = 0;
	double Area = 0, AreaAll = 0;
	for (int i = 0; i<contours.size(); i++)
	{
		boundRect[i] = boundingRect((Mat)contours[i]); //查找每个轮廓的外接矩形
		x0 = boundRect[i].x;  //获得第i个外接矩形的左上角的x坐标
		y0 = boundRect[i].y; //获得第i个外接矩形的左上角的y坐标
		w0 = boundRect[i].width; //获得第i个外接矩形的宽度
		h0 = boundRect[i].height; //获得第i个外接矩形的高度

		//计算面积
		double Area = contourArea(contours[i]);//计算第i个轮廓的面积
		AreaAll = Area + AreaAll;

		//筛选
		if (500>w0>100 && 500>h0>100)
			rectangle(result, Point(x0, y0), Point(x0 + w0, y0 + h0), Scalar(0, 255, 0), 2, 8); //绘制第i个外接矩形

		//文字输出
		Point org(10, 35);
		if (i >= 1 && AreaAll >= 10000)
			putText(result, "Is Blocked ", org, CV_FONT_HERSHEY_SCRIPT_SIMPLEX, 1.5f, Scalar(0, 255, 0), 2);

	}
	return result;
}

int main()
{
	VideoCapture cap;
	cap.open(0);
	if (!cap.isOpened())
		return 0;
	double fps = cap.get(CV_CAP_PROP_FPS); //获取视频帧率
	double pauseTime = 1000 / fps; //两幅画面中间间隔
	namedWindow("Cap");
	setMouseCallback("Cap", onMouse);

	Mat background;
	Mat image;
	Mat ImageROI;
	Mat result;
	int count = 0;
	int flag = 0;

	while (1)
	{
		if (!leftButtonDownFlag) //判定鼠标左键没有按下，采取播放视频，否则暂停
		{
			cap >> frame;
		}

		if (waitKey(50) == 27)  //Esc键按下退出播放
		{
			break;
		}

		if (originalPoint != processPoint &&!leftButtonDownFlag)
		{
			rectangle(frame, originalPoint, processPoint, Scalar(255, 0, 0), 2);
			ImageROI = frame(Rect(originalPoint, processPoint)); //子图像显示
			imshow("ROI", ImageROI);
			flag = 1;
		}

		cap >> frame;
		if (frame.empty())
			break;
		else
		{
			count++;
			if (count == 1)
				background = frame.clone(); 

			if (flag == 1)
			{
				rectangle(background, originalPoint, processPoint, Scalar(255, 0, 0), 2);
				image = background(Rect(originalPoint, processPoint));
				result = MoveDetect(image, ImageROI);
				imshow("ROI", result);
			}
			imshow("Cap",frame);
		}

	}
	cap.release();
}

问题版 ：

#include "core/core.hpp"  
#include "highgui/highgui.hpp"  
#include "imgproc/imgproc.hpp"  
#include<iostream>  

using namespace cv;
using namespace std;

Mat frame;
Mat frameCopy; //绘制矩形框时用来拷贝原图的图像
bool leftButtonDownFlag = false; //左键单击后视频暂停播放的标志位
Point originalPoint; //矩形框起点
Point processPoint; //矩形框终点

//*******************************************************************//  
//鼠标回调函数  
void onMouse(int event, int x, int y, int flags, void *ustc)
{

	if (event == CV_EVENT_LBUTTONDOWN)
	{
		leftButtonDownFlag = true; //标志位
		originalPoint = Point(x, y);  //设置左键按下点的矩形起点
		processPoint = originalPoint;
	}
	if (event == CV_EVENT_MOUSEMOVE&&leftButtonDownFlag)
	{
		frameCopy = frame.clone();
		processPoint = Point(x, y);
		if (originalPoint != processPoint)
		{
			//在复制的图像上绘制矩形
			rectangle(frameCopy, originalPoint, processPoint, Scalar(255, 0, 0), 2);
		}
		imshow("Cap", frameCopy);
	}
	if (event == CV_EVENT_LBUTTONUP)
	{
		leftButtonDownFlag = false;
		Mat rectImage = frame(Rect(originalPoint, processPoint)); //子图像显示
		imshow("ROI", rectImage);
	}

}

Mat MoveDetect(Mat background, Mat img)
{
	//将background和img转为灰度图
	Mat result = img.clone();
	Mat gray1, gray2;
	cvtColor(background, gray1, CV_BGR2GRAY);
	cvtColor(img, gray2, CV_BGR2GRAY);

	//进行canny边缘检测 
	Canny(background, background, 0, 30, 3);

	//将background和img做差；对差值图diff进行阈值化处理
	Mat diff;
	absdiff(gray1, gray2, diff);
	//imshow("absdiss", diff);
	threshold(diff, diff, 50, 255, CV_THRESH_BINARY);
	//imshow("threshold", diff);

	/*
	//腐蚀膨胀消除噪音
	Mat element = getStructuringElement(MORPH_RECT, Size(3, 3));
	Mat element2 = getStructuringElement(MORPH_RECT, Size(15, 15));
	erode(diff, diff, element);
	//imshow("erode", diff);
	dilate(diff, diff, element2);
	//imshow("dilate", diff);
	*/

	//二值化后使用中值滤波+膨胀
	Mat element = getStructuringElement(MORPH_RECT, Size(11, 11));
	medianBlur(diff, diff, 5);//中值滤波
	//imshow("medianBlur", diff);
	dilate(diff, diff, element);
	//blur(diff, diff, Size(10, 10)); //均值滤波
	//imshow("dilate", diff);

	//查找并绘制轮廓
	vector<vector<Point>> contours;
	vector<Vec4i> hierarcy;
	findContours(diff, contours, hierarcy, CV_RETR_EXTERNAL, CHAIN_APPROX_NONE); //查找轮廓
	vector<Rect> boundRect(contours.size()); //定义外接矩形集合
	//drawContours(img2, contours, -1, Scalar(0, 0, 255), 1, 8);  //绘制轮廓

	//查找正外接矩形
	int x0 = 0, y0 = 0, w0 = 0, h0 = 0;
	double Area = 0, AreaAll = 0;
	for (int i = 0; i<contours.size(); i++)
	{
		boundRect[i] = boundingRect((Mat)contours[i]); //查找每个轮廓的外接矩形
		x0 = boundRect[i].x;  //获得第i个外接矩形的左上角的x坐标
		y0 = boundRect[i].y; //获得第i个外接矩形的左上角的y坐标
		w0 = boundRect[i].width; //获得第i个外接矩形的宽度
		h0 = boundRect[i].height; //获得第i个外接矩形的高度

		//计算面积
		double Area = contourArea(contours[i]);//计算第i个轮廓的面积
		AreaAll = Area + AreaAll;

		//筛选
		if (w0>80 && h0>80)
			rectangle(result, Point(x0, y0), Point(x0 + w0, y0 + h0), Scalar(0, 255, 0), 2, 8); //绘制第i个外接矩形

		//文字输出
		Point org(10, 35);
		if (i >= 1 && AreaAll >= 6400)
			putText(result, "Is Blocked ", org, CV_FONT_HERSHEY_SIMPLEX, 0.8f, Scalar(0, 255, 0), 2);

	}
	return result;
}

int main()
{
	VideoCapture cap;
	cap.open(0);
	if (!cap.isOpened())
		return 0;
	double fps = cap.get(CV_CAP_PROP_FPS); //获取视频帧率
	double pauseTime = 1000 / fps; //两幅画面中间间隔
	namedWindow("Cap");
	setMouseCallback("Cap", onMouse);

	Mat background;
	Mat result;
	int count = 0;
	while (1)
	{
		if (!leftButtonDownFlag) //判定鼠标左键没有按下，采取播放视频，否则暂停
		{
			cap >> frame;
		}

		if (waitKey(50) == 27)  //Esc键按下退出播放
		{
			break;
		}

		if (originalPoint != processPoint&&!leftButtonDownFlag)
		{
			rectangle(frame, originalPoint, processPoint, Scalar(255, 0, 0), 2);
			Mat ImageROI= frame(Rect(originalPoint, processPoint)); //子图像显示
			imshow("ROI", ImageROI);
		}
		
		cap >> frame;
		if (frame.empty())
			break;
		else
		{
			count++;
			if (count == 1)

				background = frame.clone();
			result = MoveDetect(background, frame);

			imshow("Cap",result);
		}

	}
	cap.release();
}