jashliao 用 VC++ 實現 fanfuhan OpenCV 教學078 ~ opencv-078-使用簡單HSV產生ROI實作 提取 前景&後景 分離 去背/替換背景進而達到識別(尋找/標記)與跟踪(鎖定/定位)視頻(影片)中的特定顏色對象

資料來源: https://fanfuhan.github.io/

https://fanfuhan.github.io/2019/04/24/opencv-078/

GITHUB:https://github.com/jash-git/fanfuhan_ML_OpenCV

https://github.com/jash-git/jashliao-implements-FANFUHAN-OPENCV-with-VC

★前言:

★主題:
    圖像處理與二值分析的視頻版本，通過讀取視頻每一幀的圖像，然後對圖像二值分析，得到指定的色塊區域，主要步驟如下：

        01. 色彩轉換BGR2HSV
        02. inRange提取顏色區域mask
        03. 對mask區域進行二值分析得到位置與輪廓信息
        04. 繪製外接橢圓與中心位置
        05. 顯示結果

    其中涉及到的知識點主要包括圖像處理、色彩空間轉換、形態學、輪廓分析等。

★C++

// VC_FANFUHAN_OPENCV078.cpp : 定義主控台應用程式的進入點。
//
/*
// Debug | x32
通用屬性
| C/C++
|	| 一般
|		| 其他 Include 目錄 -> ..\..\opencv411_x64\include
|
| 連結器
| 	|一一般
|		|  其他程式庫目錄 -> ..\..\opencv411_x64\lib
|
| 	|一輸入
|		| 其他相依性 -> opencv_world411d.lib;%(AdditionalDependencies)
// Releas | x64
組態屬性
| C/C++
|	| 一般
|		| 其他 Include 目錄 -> ..\..\opencv411_x64\include;%(AdditionalDependencies)
|
| 連結器
| 	|一般
|		| 其他程式庫目錄 -> ..\..\opencv411_x64\lib;%(AdditionalDependencies)
|
| 	|一輸入
|		| 其他相依性 -> opencv_world411.lib;%(AdditionalDependencies)
*/

#include "stdafx.h"
#include <iostream>
#include <opencv2/opencv.hpp>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>

using namespace std;
using namespace cv;

void blur_demo(Mat &image, Mat &sum);
void edge_demo(Mat &image, Mat &sum);
int getblockSum(Mat &sum, int x1, int y1, int x2, int y2, int i);

void showHistogram(InputArray src, cv::String StrTitle);
void backProjection_demo(Mat &mat, Mat &model);
void blur3x3(Mat &src, Mat *det);

void add_salt_pepper_noise(Mat &image);
void add_gaussian_noise(Mat &image);

void USMImage(Mat src, Mat &usm, float fltPar);

void pyramid_up(Mat &image, vector<Mat> &pyramid_images, int level);
void pyramid_down(vector<Mat> &pyramid_images);

void laplaian_demo(vector<Mat> &pyramid_images, Mat &image);

void connected_component_demo(Mat &image);
void componentwithstats_demo(Mat &image);

void contours_info(Mat &image, vector<vector<Point>> &pts);
void contours_info(Mat &image, vector<vector<Point>> &pts, int threshold01, int threshold02);

void  open_demo(bool blnopen);
void  close_demo();

void sort_box(vector<Rect> &boxes);
Mat get_template(Mat &binary, vector<Rect> &rects);
void detect_defects(Mat &binary, vector<Rect> &rects, Mat &tpl, vector<Rect> &defects);

void process_frame(Mat &image);

void pause()
{
	printf("Press Enter key to continue...");
	fgetc(stdin);
}
int main()
{
	VideoCapture capture("../../images/color_object.mp4");
	if (!capture.isOpened()) {
		cout << "could not open video.." << endl;
		pause();
		return -1;
	}
	else
	{
		int fps = capture.get(CAP_PROP_FPS);
		int width = capture.get(CAP_PROP_FRAME_WIDTH);
		int height = capture.get(CAP_PROP_FRAME_HEIGHT);
		int num_of_frames = capture.get(CAP_PROP_FRAME_COUNT);
		printf("frame width: %d, frame height: %d, FPS : %d \n", width, height, fps);

		Mat frame;
		while (true) {
			bool ret = capture.read(frame);
			if (!ret) break;
			imshow("input", frame);
			char c = waitKey(50);
			process_frame(frame);
			imshow("result", frame);
			if (c == 27) {
				break;
			}
		}
		waitKey(0);
	}
	return 0;
}

void process_frame(Mat &image) {
	Mat hsv, mask;
	// 转换色彩空间
	cvtColor(image, hsv, COLOR_BGR2HSV);

	// 提取颜色区域mask
	inRange(hsv, Scalar(0, 43, 46), Scalar(10, 255, 255), mask);
	Mat se = getStructuringElement(MORPH_RECT, Size(15, 15));
	morphologyEx(mask, mask, MORPH_OPEN, se);

	// 寻找最大轮廓
	vector<vector<Point>> contours;
	vector<Vec4i> hierarchy;
	findContours(mask, contours, hierarchy, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE);
	int index = -1;
	int max = 0;
	for (size_t t = 0; t < contours.size(); t++) {
		double area = contourArea(contours[t]);
		if (area > max) {
			max = area;
			index = t;
		}
	}

	// 绘制外接轮廓
	if (index >= 0) {
		RotatedRect rect = minAreaRect(contours[index]);
		ellipse(image, rect, Scalar(0, 255, 0), 2);
		circle(image, rect.center, 2, Scalar(255, 0, 0), 2);
	}
}

void detect_defects(Mat &binary, vector<Rect> &rects, Mat &tpl, vector<Rect> &defects) {
	int height = tpl.rows;
	int width = tpl.cols;
	int index = 1;
	int size = rects.size();
	// 发现缺失
	for (int i = 0; i < size; ++i) {
		Mat roi = binary(rects[i]);
		resize(roi, roi, tpl.size());//調整待測物的大小與模板一致
		Mat mask;
		subtract(tpl, roi, mask);//圖像相減
		Mat se = getStructuringElement(MORPH_RECT, Size(5, 5));
		morphologyEx(mask, mask, MORPH_OPEN, se);//開運算-藉此去白色雜訊
		threshold(mask, mask, 0, 255, THRESH_BINARY);
		int count = 0;
		for (int row = 0; row < height; ++row) {
			for (int col = 0; col < width; ++col) {
				int pv = mask.at<uchar>(row, col);
				if (pv == 255) {
					++count;
				}
			}
		}
		if (count > 0) {
			defects.push_back(rects[i]);
		}
	}
}

Mat get_template(Mat &binary, vector<Rect> &rects) //以範圍最大為良品基準
{
	return binary(rects[0]);
}

void sort_box(vector<Rect> &boxes) {
	int size = boxes.size();
	for (int i = 0; i < size - 1; ++i) {
		for (int j = i; j < size; ++j) {
			if (boxes[j].y < boxes[i].y) {
				Rect tmp = boxes[i];
				boxes[i] = boxes[j];
				boxes[j] = tmp;
			}
		}
	}
}

void close_demo()
{
	//讀取圖像     
	Mat src = imread("../images/morph3.png");
	imshow("close_demo_input", src);

	//二值圖像
	Mat gray, binary;
	cvtColor(src, gray, COLOR_BGR2GRAY);
	threshold(gray, binary, 0, 255, THRESH_BINARY | THRESH_OTSU);
	imshow("close_demo_binary", binary);

	//閉操作//
	//Mat se = getStructuringElement(MORPH_ELLIPSE, Size(30, 30), Point(-1, -1));
	//Mat se = getStructuringElement(MORPH_RECT, Size(30, 30), Point(-1 , -1));
	Mat se = getStructuringElement(MORPH_RECT, Size(35, 35), Point(-1, -1));
	morphologyEx(binary, binary, MORPH_CLOSE, se);
	imshow("close_demo rect=35,35 ", binary);
}

void open_demo(bool blnopen)
{
	//讀取圖像     
	Mat src = imread("../images/fill.png");
	imshow("open_demo_input", src);

	//二值圖像
	Mat gray, binary;
	cvtColor(src, gray, COLOR_BGR2GRAY);
	if (blnopen)
	{
		threshold(gray, binary, 0, 255, THRESH_BINARY_INV | THRESH_OTSU);
	}
	else
	{
		threshold(gray, binary, 0, 255, THRESH_BINARY | THRESH_OTSU);
	}
	imshow("open_demo_binary", binary);

	//開操作 -去除黑色雜訊 強化/獲取 連通元件(mask) 保留長（x＝25）底線（y＝1）
	Mat se = getStructuringElement(MORPH_RECT, Size(25, 1), Point(-1, -1));
	if (blnopen)
	{
		morphologyEx(binary, binary, MORPH_OPEN, se);
	}
	else
	{
		morphologyEx(binary, binary, MORPH_CLOSE, se);//
		threshold(binary, binary, 0, 255, THRESH_BINARY_INV | THRESH_OTSU);
	}
	imshow("open_op", binary);

	//繪製填空位置
	vector < vector <Point>> contours;
	vector <Vec4i> hierarhy;
	findContours(binary, contours, hierarhy, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE, Point(-1, -1));
	for (size_t t = 0; t < contours.size(); t++)
	{
		Rect roi = boundingRect(contours[t]);
		roi.y = roi.y - 10;
		roi.height = 12;
		rectangle(src, roi, Scalar(0, 0, 255));
	}

	//顯示結果
	imshow("open_demo", src);
}
void contours_info(Mat &image, vector<vector<Point>> &pts)//目標物為同類型(顏色) ~ 抓取輪廓(findContours)函數
{
	// 去噪声与二值化
	//彩色轉二值化步驟(SOP) 彩色 -> 高斯模糊(去雜訊) -> 轉灰階 -> 二值化
	Mat dst, gray, binary00;
	GaussianBlur(image, dst, Size(3, 3), 0, 0);
	cvtColor(dst, gray, COLOR_BGR2GRAY);
	threshold(gray, binary00, 0, 255, THRESH_BINARY | THRESH_OTSU);
	imshow("binary00", binary00);

	vector<Vec4i> hierarchy00;
	Scalar color = Scalar(255, 0, 0);
	/*
	void findContours(InputOutputArray image,OutputArrayOfArrays contours,OutputArray hierarchy,int mode,int method,Point offset = Point() )
	各個參數詳解如下：
	image表示輸入圖像，必須是二值圖像，二值圖像可以threshold輸出、Canny輸出、inRange輸出、自適應閾值輸出等。
	contours獲取的輪廓，每個輪廓是一系列的點集合
	hierarchy輪廓的層次信息，每個輪廓有四個相關信息，分別是同層下一個、前一個、第一個子節點、父節點
	mode 表示輪廓尋找時候的拓撲結搆返回
	-RETR_EXTERNAL表示只返回最外層輪廓
	-RETR_TREE表示返回輪廓樹結搆
	method表示輪廓點集合取得是基於什么算法，常見的是基於CHAIN_APPROX_SIMPLE鏈式編碼方法
	*/
	findContours(binary00, pts, hierarchy00, RETR_TREE, CHAIN_APPROX_SIMPLE, Point());

}
void contours_info(Mat &image, vector<vector<Point>> &pts, int threshold01, int threshold02)//目標物非同類型(顏色) ~ 抓取輪廓(findContours)函數
{
	Mat dst, gray, binary01;
	//彩色轉二值化步驟(直接使用Canny)
	/*
	void Canny(InputArray image, OutputArray edges, double threshold1, double threshold2, int apertureSize=3, bool L2gradient=false )
	image, edges：輸入和輸出的圖片。
	threshold1, threshold2：用來區分 strong edge 和 weak edge，範圍都是 0 ~ 255，會在實作過程中進一步討論，通常選擇 threshold2 / threshold1 = 1/2 ~ 1/3，例如 (70, 140), (70, 210)
	apertureSize：用來計算梯度的 kernel size，也就是 Sobel 的 ksize
	L2gradient：選擇要用 L1 norm（絕對值平均）還是 L2 norm（平方根）當作梯度的大小。預設是用 L1 norm
	*/
	Canny(image, binary01, threshold01, threshold02);

	// 膨胀
	/*
	OpenCV提供getStructuringElement()讓我們得到要進行侵蝕或膨脹的模板
	Mat getStructuringElement(int shape, Size ksize, Point anchor=Point(-1,-1))
	shape：模板形狀，有MORPH_RECT、MORPH_ELLIPSE、MORPH_CROSS三種可選。
	ksize：模板尺寸。
	*/
	Mat k = getStructuringElement(MORPH_RECT, Size(3, 3), Point(-1, -1));
	/*
	OpenCV膨脹
	dilate(const Mat &src, Mat &dst, Mat kernel, Point anchor=Point(-1,-1), int iterations=1)
	src：輸入圖，可以多通道，深度可為CV_8U、CV_16U、CV_16S、CV_32F或CV_64F。
	dst：輸出圖，和輸入圖尺寸、型態相同。
	kernel：結構元素，如果kernel=Mat()則為預設的3×3矩形，越大膨脹效果越明顯。
	anchor：原點位置，預設為結構元素的中央。
	iterations：執行次數，預設為1次，執行越多次膨脹效果越明顯。
	*/
	dilate(binary01, binary01, k);
	imshow("binary01", binary01);

	vector<Vec4i> hierarchy01;
	Scalar color = Scalar(255, 0, 0);
	findContours(binary01, pts, hierarchy01, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE, Point());
}

void componentwithstats_demo(Mat &image)//八方鍊碼:元件標記/尋找/計算(計數)/參數:中心位置、起始座標、長、寬、面積，取得分類的所需資訊作業 + 繪製各元件的外矩形
{
	// extract labels
	//彩色轉二值化步驟(SOP) 彩色 -> 高斯模糊(去雜訊) -> 轉灰階 -> 二值化
	Mat gray, binary;
	GaussianBlur(image, image, Size(3, 3), 0);
	cvtColor(image, gray, COLOR_BGR2GRAY);
	threshold(gray, binary, 0, 255, THRESH_BINARY | THRESH_OTSU);
	imshow("input_binary", binary);
	showHistogram(binary, "Histogram_input_binary");

	Mat labels = Mat::zeros(image.size(), CV_32S);
	Mat stats, centroids;
	int num_labels = connectedComponentsWithStats(binary, labels, stats, centroids, 8, 4);
	cout << "total labels : " << num_labels - 1 << endl;
	vector<Vec3b> colors(num_labels);

	// 背景颜色
	colors[0] = Vec3b(0, 0, 0);

	// 目标颜色
	RNG rng;
	for (int i = 1; i < num_labels; ++i) {
		colors[i] = Vec3b(rng.uniform(0, 256), rng.uniform(0, 256), rng.uniform(0, 256));
	}

	// 抽取统计信息
	Mat dst = image.clone();
	for (int i = 1; i < num_labels; ++i) {
		// 中心位置
		int cx = centroids.at<double>(i, 0);
		int cy = centroids.at<double>(i, 1);

		// 统计信息
		int x = stats.at<int>(i, CC_STAT_LEFT);
		int y = stats.at<int>(i, CC_STAT_TOP);
		int w = stats.at<int>(i, CC_STAT_WIDTH);
		int h = stats.at<int>(i, CC_STAT_HEIGHT);
		int area = stats.at<int>(i, CC_STAT_AREA);

		// 中心位置绘制
		circle(dst, Point(cx, cy), 2, Scalar(0, 255, 0), 2);

		// 外接矩形
		Rect rect(x, y, w, h);
		rectangle(dst, rect, colors[i]);
		putText(dst, format("num:%d", i), Point(x, y), FONT_HERSHEY_SIMPLEX,
			.5, Scalar(0, 0, 255), 1);
		printf("num : %d, rice area : %d\n", i, area);
	}

	imshow("result", dst);
}

void connected_component_demo(Mat &image) //八方鍊碼 元件 計數(計算) 數量 / 標色
{
	// extract labels
	Mat gray, binary;

	//彩色轉二值化步驟(SOP) 彩色 -> 高斯模糊(去雜訊) -> 轉灰階 -> 二值化
	GaussianBlur(image, image, Size(3, 3), 0);
	cvtColor(image, gray, COLOR_BGR2GRAY);
	threshold(gray, binary, 0, 255, THRESH_BINARY | THRESH_OTSU);
	imshow("input_binary", binary);
	showHistogram(binary, "Histogram_input_binary");

	//計算(計數) 元件(mask) 數量 和 所需元素顏色數量陣列
	/*
	参数介绍如下：
	image：也就是输入图像，必须是二值图，即8位单通道图像。（因此输入图像必须先进行二值化处理才能被这个函数接受）
	返回值：
	num_labels：所有连通域的数目
	labels：图像上每一像素的标记，用数字1、2、3…表示（不同的数字表示不同的连通域）
	*/
	Mat labels = Mat::zeros(image.size(), CV_32S);//背景也會被算一個區域
	int num_labels = connectedComponents(binary, labels, 8, CV_32S);//數量
	cout << "total labels : " << num_labels - 1 << endl;
	vector<Vec3b> colors(num_labels);

	// 背景颜色
	colors[0] = Vec3b(0, 0, 0);

	// 目标颜色
	RNG rng;
	for (int i = 1; i < num_labels; ++i) {
		colors[i] = Vec3b(rng.uniform(0, 256), rng.uniform(0, 256), rng.uniform(0, 256));
	}

	// 给结果着色
	Mat dst = Mat::zeros(image.size(), image.type());
	for (int row = 0; row < image.rows; ++row) {
		for (int col = 0; col < image.cols; ++col) {
			int label = labels.at<int>(row, col);
			if (label == 0) continue;
			dst.at<Vec3b>(row, col) = colors[label];
		}
	}

	imshow("result", dst);
}

void laplaian_demo(vector<Mat> &pyramid_images, Mat &image)//拉普拉斯金字塔
{
	for (int i = pyramid_images.size() - 1; i > -1; --i)
	{
		Mat dst;
		if (i - 1 < 0)
		{
			pyrUp(pyramid_images[i], dst, image.size());
			subtract(image, dst, dst);//圖像相減
			dst = dst + Scalar(127, 127, 127); //调亮度， 实际中不能这么用
			imshow(format("laplaian_layer_%d", i), dst);
		}
		else
		{
			pyrUp(pyramid_images[i], dst, pyramid_images[i - 1].size());
			subtract(pyramid_images[i - 1], dst, dst);//圖像相減
			dst = dst + Scalar(127, 127, 127); //調亮度， 实际中不能这么用
			imshow(format("laplaian_layer_%d", i), dst);
		}
	}
}

void pyramid_down(vector<Mat> &pyramid_images)//高斯金字塔01
{
	for (int i = pyramid_images.size() - 1; i > -1; --i) {
		Mat dst;
		/*
		pyrUp(tmp, dst, Size(tmp.cols * 2, tmp.rows * 2))
		tmp: 當前影象， 初始化為原影象 src 。
		dst : 目的影象(顯示影象，為輸入影象的兩倍)
		Size(tmp.cols * 2, tmp.rows * 2) : 目的影象大小， 既然我們是向上取樣， pyrUp 期待一個兩倍於輸入影象(tmp)的大小。
		*/
		pyrUp(pyramid_images[i], dst);
		imshow(format("pyramid_down_%d", i), dst);
	}
}

void pyramid_up(Mat &image, vector<Mat> &pyramid_images, int level)//高斯金字塔02
{
	Mat temp = image.clone();
	Mat dst;
	for (int i = 0; i < level; ++i)
	{
		/*
		pyrDown( tmp, dst, Size( tmp.cols/2, tmp.rows/2 ))
		tmp: 當前影象， 初始化為原影象 src 。
		dst: 目的影象( 顯示影象，為輸入影象的一半)
		Size( tmp.cols/2, tmp.rows/2 ) :目的影象大小， 既然我們是向下取樣， pyrDown 期待一個一半於輸入影象( tmp)的大小。
		注意輸入影象的大小(在兩個方向)必須是2的冥，否則，將會顯示錯誤。
		最後，將輸入影象 tmp 更新為當前顯示影象, 這樣後續操作將作用於更新後的影象。
		tmp = dst;
		*/
		pyrDown(temp, dst);
		imshow(format("pyramid_up_%d", i), dst);
		temp = dst.clone();
		pyramid_images.push_back(temp);
	}
}

void USMImage(Mat src, Mat &usm, float fltPar)//圖像銳化增强演算法(USM)
{
	Mat blur_img;
	/*
	USM銳化公式表示如下：
	（源圖像– w*高斯模糊）/（1-w）；其中w表示權重（0.1～0.9），默認為0.6
	OpenCV中的代碼實現步驟
	– 高斯模糊
	– 權重疊加
	– 輸出結果
	*/
	GaussianBlur(src, blur_img, Size(0, 0), 25);
	addWeighted(src, (1 + fltPar), blur_img, (fltPar*-1), 0, usm);//原圖 : 模糊圖片= 1.5 : -0.5 的比例進行混合
	imshow("usm", usm);
	showHistogram(usm, "Histogram_input_usm");
}

void blur_demo(Mat &image, Mat &sum)
{
	int w = image.cols;
	int h = image.rows;
	Mat result = Mat::zeros(image.size(), image.type());
	int x2 = 0, y2 = 0;
	int x1 = 0, y1 = 0;
	int ksize = 5;
	int radius = ksize / 2;
	int ch = image.channels();
	int cx = 0, cy = 0;
	for (int row = 0; row < h + radius; row++) {
		y2 = (row + 1)>h ? h : (row + 1);
		y1 = (row - ksize) < 0 ? 0 : (row - ksize);
		for (int col = 0; col < w + radius; col++) {
			x2 = (col + 1)>w ? w : (col + 1);
			x1 = (col - ksize) < 0 ? 0 : (col - ksize);
			cx = (col - radius) < 0 ? 0 : col - radius;
			cy = (row - radius) < 0 ? 0 : row - radius;
			int num = (x2 - x1)*(y2 - y1);
			for (int i = 0; i < ch; i++) {
				// 积分图查找和表，计算卷积
				int s = getblockSum(sum, x1, y1, x2, y2, i);
				result.at<Vec3b>(cy, cx)[i] = saturate_cast<uchar>(s / num);
			}
		}
	}
	imshow("blur_demo", result);
}

/**
* 3x3 sobel 垂直边缘检测演示
*/
void edge_demo(Mat &image, Mat &sum)
{
	int w = image.cols;
	int h = image.rows;
	Mat result = Mat::zeros(image.size(), CV_32SC3);
	int x2 = 0, y2 = 0;
	int x1 = 0, y1 = 0;
	int ksize = 3; // 算子大小，可以修改，越大边缘效应越明显
	int radius = ksize / 2;
	int ch = image.channels();
	int cx = 0, cy = 0;
	for (int row = 0; row < h + radius; row++) {
		y2 = (row + 1)>h ? h : (row + 1);
		y1 = (row - ksize) < 0 ? 0 : (row - ksize);
		for (int col = 0; col < w + radius; col++) {
			x2 = (col + 1)>w ? w : (col + 1);
			x1 = (col - ksize) < 0 ? 0 : (col - ksize);
			cx = (col - radius) < 0 ? 0 : col - radius;
			cy = (row - radius) < 0 ? 0 : row - radius;
			int num = (x2 - x1)*(y2 - y1);
			for (int i = 0; i < ch; i++) {
				// 积分图查找和表，计算卷积
				int s1 = getblockSum(sum, x1, y1, cx, y2, i);
				int s2 = getblockSum(sum, cx, y1, x2, y2, i);
				result.at<Vec3i>(cy, cx)[i] = saturate_cast<int>(s2 - s1);
			}
		}
	}
	Mat dst, gray;
	convertScaleAbs(result, dst);
	normalize(dst, dst, 0, 255, NORM_MINMAX);
	cvtColor(dst, gray, COLOR_BGR2GRAY);
	imshow("edge_demo", gray);
}

int getblockSum(Mat &sum, int x1, int y1, int x2, int y2, int i) {
	int tl = sum.at<Vec3i>(y1, x1)[i];
	int tr = sum.at<Vec3i>(y2, x1)[i];
	int bl = sum.at<Vec3i>(y1, x2)[i];
	int br = sum.at<Vec3i>(y2, x2)[i];
	int s = (br - bl - tr + tl);
	return s;
}

void add_gaussian_noise(Mat &image)//高斯雜訊
{
	Mat noise = Mat::zeros(image.size(), image.type());
	// 产生高斯噪声
	randn(noise, (15, 15, 15), (30, 30, 30));
	Mat dst;
	add(image, noise, dst);
	image = dst.clone();//dst.copyTo(image);//圖像複製
						//imshow("gaussian_noise", dst);
}

void add_salt_pepper_noise(Mat &image)//白雜訊
{
	// 随机数产生器
	RNG rng(12345);
	for (int i = 0; i < 1000; ++i) {
		int x = rng.uniform(0, image.rows);
		int y = rng.uniform(0, image.cols);
		if (i % 2 == 1) {
			image.at<Vec3b>(y, x) = Vec3b(255, 255, 255);
		}
		else {
			image.at<Vec3b>(y, x) = Vec3b(0, 0, 0);
		}
	}
	//imshow("saltp_epper", image);
}

void blur3x3(Mat &src, Mat *det)
{
	// 3x3 均值模糊，自定义版本实现
	for (int row = 1; row < src.rows - 1; row++) {
		for (int col = 1; col < src.cols - 1; col++) {
			Vec3b p1 = src.at<Vec3b>(row - 1, col - 1);
			Vec3b p2 = src.at<Vec3b>(row - 1, col);
			Vec3b p3 = src.at<Vec3b>(row - 1, col + 1);
			Vec3b p4 = src.at<Vec3b>(row, col - 1);
			Vec3b p5 = src.at<Vec3b>(row, col);
			Vec3b p6 = src.at<Vec3b>(row, col + 1);
			Vec3b p7 = src.at<Vec3b>(row + 1, col - 1);
			Vec3b p8 = src.at<Vec3b>(row + 1, col);
			Vec3b p9 = src.at<Vec3b>(row + 1, col + 1);

			int b = p1[0] + p2[0] + p3[0] + p4[0] + p5[0] + p6[0] + p7[0] + p8[0] + p9[0];
			int g = p1[1] + p2[1] + p3[1] + p4[1] + p5[1] + p6[1] + p7[1] + p8[1] + p9[1];
			int r = p1[2] + p2[2] + p3[2] + p4[2] + p5[2] + p6[2] + p7[2] + p8[2] + p9[2];

			det->at<Vec3b>(row, col)[0] = saturate_cast<uchar>(b / 9);
			det->at<Vec3b>(row, col)[1] = saturate_cast<uchar>(g / 9);
			det->at<Vec3b>(row, col)[2] = saturate_cast<uchar>(r / 9);
		}
	}
}

void backProjection_demo(Mat &image, Mat &model)//反向投影
{
	Mat image_hsv, model_hsv;
	cvtColor(image, image_hsv, COLOR_BGR2HSV);//彩色轉HSV
	cvtColor(model, model_hsv, COLOR_BGR2HSV);

	// 定义直方图参数与属性
	int h_bins = 32, s_bins = 32;
	int histSize[] = { h_bins, s_bins };//要切分的像素強度值範圍，預設為256。每個channel皆可指定一個範圍。例如，[32,32,32] 表示RGB三個channels皆切分為32區段
	float h_ranges[] = { 0, 180 }, s_ranges[] = { 0, 256 };
	const float* ranges[] = { h_ranges, s_ranges };
	int channels[] = { 0, 1 };

	Mat roiHist;//計算ROI的直方圖
	calcHist(&model_hsv, 1, channels, Mat(), roiHist, 2, histSize, ranges);
	normalize(roiHist, roiHist, 0, 255, NORM_MINMAX, -1, Mat());

	Mat roiproj, backproj;
	calcBackProject(&image_hsv, 1, channels, roiHist, roiproj, ranges);//使用反向投影 產生ROI(前景)的mask
	bitwise_not(roiproj, backproj);//產生背景的mask
	imshow("ROIProj", roiproj);
	imshow("BackProj", backproj);
}

void showHistogram(InputArray src, cv::String StrTitle)//直方圖
{
	bool blnGray = false;
	if (src.channels() == 1)
	{
		blnGray = true;
	}

	// 三通道/單通道 直方圖 紀錄陣列
	vector<Mat> bgr_plane;
	vector<Mat> gray_plane;

	// 定义参数变量
	const int channels[1] = { 0 };
	const int bins[1] = { 256 };
	float hranges[2] = { 0, 255 };
	const float *ranges[1] = { hranges };
	Mat b_hist, g_hist, r_hist, hist;
	// 计算三通道直方图
	/*
	void calcHist( const Mat* images, int nimages,const int* channels, InputArray mask,OutputArray hist, int dims, const int* histSize,const float** ranges, bool uniform=true, bool accumulate=false );
	1.輸入的圖像數組
	2.輸入數組的個數
	3.通道數
	4.掩碼
	5.直方圖
	6.直方圖維度
	7.直方圖每個維度的尺寸數組
	8.每一維數組的範圍
	9.直方圖是否是均勻
	10.配置階段不清零
	*/
	if (blnGray)
	{
		split(src, gray_plane);
		calcHist(&gray_plane[0], 1, 0, Mat(), hist, 1, bins, ranges);
	}
	else
	{
		split(src, bgr_plane);
		calcHist(&bgr_plane[0], 1, 0, Mat(), b_hist, 1, bins, ranges);
		calcHist(&bgr_plane[1], 1, 0, Mat(), g_hist, 1, bins, ranges);
		calcHist(&bgr_plane[2], 1, 0, Mat(), r_hist, 1, bins, ranges);
	}

	/*
	* 显示直方图
	*/
	int hist_w = 512;
	int hist_h = 400;
	int bin_w = cvRound((double)hist_w / bins[0]);
	Mat histImage = Mat::zeros(hist_h, hist_w, CV_8UC3);
	// 归一化直方图数据
	if (blnGray)
	{
		normalize(hist, hist, 0, histImage.rows, NORM_MINMAX, -1);
	}
	else
	{
		normalize(b_hist, b_hist, 0, histImage.rows, NORM_MINMAX, -1);
		normalize(g_hist, g_hist, 0, histImage.rows, NORM_MINMAX, -1);
		normalize(r_hist, r_hist, 0, histImage.rows, NORM_MINMAX, -1);
	}

	// 绘制直方图曲线
	for (int i = 1; i < bins[0]; ++i)
	{
		if (blnGray)
		{
			line(histImage, Point(bin_w * (i - 1), hist_h - cvRound(hist.at<float>(i - 1))),
				Point(bin_w * (i), hist_h - cvRound(hist.at<float>(i))), Scalar(255, 255, 255),
				2, 8, 0);
		}
		else
		{
			line(histImage, Point(bin_w * (i - 1), hist_h - cvRound(b_hist.at<float>(i - 1))),
				Point(bin_w * (i), hist_h - cvRound(b_hist.at<float>(i))), Scalar(255, 0, 0),
				2, 8, 0);
			line(histImage, Point(bin_w * (i - 1), hist_h - cvRound(g_hist.at<float>(i - 1))),
				Point(bin_w * (i), hist_h - cvRound(g_hist.at<float>(i))), Scalar(0, 255, 0),
				2, 8, 0);
			line(histImage, Point(bin_w * (i - 1), hist_h - cvRound(r_hist.at<float>(i - 1))),
				Point(bin_w * (i), hist_h - cvRound(r_hist.at<float>(i))), Scalar(0, 0, 255),
				2, 8, 0);
		}


	}
	imshow(StrTitle, histImage);
}

★Python

import cv2 as cv
import numpy as np

capture = cv.VideoCapture("D:/images/video/test.mp4")
height = capture.get(cv.CAP_PROP_FRAME_HEIGHT)
width = capture.get(cv.CAP_PROP_FRAME_WIDTH)
count = capture.get(cv.CAP_PROP_FRAME_COUNT)
fps = capture.get(cv.CAP_PROP_FPS)
print(height, width, count, fps)


def process(image, opt=1):
    hsv = cv.cvtColor(image, cv.COLOR_BGR2HSV)
    line = cv.getStructuringElement(cv.MORPH_RECT, (15, 15), (-1, -1))
    mask = cv.inRange(hsv, (0, 43, 46), (10, 255, 255))
    mask = cv.morphologyEx(mask, cv.MORPH_OPEN, line)

    # 轮廓提取, 发现最大轮廓
    out, contours, hierarchy = cv.findContours(mask, cv.RETR_EXTERNAL, cv.CHAIN_APPROX_SIMPLE)
    index = -1
    max = 0
    for c in range(len(contours)):
        area = cv.contourArea(contours[c])
        if area > max:
            max = area
            index = c
    # 绘制
    if index >= 0:
        rect = cv.minAreaRect(contours[index])
        cv.ellipse(image, rect, (0, 255, 0), 2, 8)
        cv.circle(image, (np.int32(rect[0][0]), np.int32(rect[0][1])), 2, (255, 0, 0), 2, 8, 0)
    return image


while(True):
    ret, frame = capture.read()
    if ret is True:
        cv.imshow("video-input", frame)
        result = process(frame)
        cv.imshow("result", result)
        c = cv.waitKey(50)
        print(c)
        if c == 27:  #ESC
            break
    else:
        break
cv.waitKey(0)
cv.destroyAllWindows()

★結果圖:

★延伸說明/重點回顧: