OpenCV入门学习（1）

Opencv学习第一天

出入每天学习点OpenCV，做做计算机视觉项目

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前言

为了项目与论文需要，现在入门 OpenCV4学习，并且学习点深度学习的东西，希望有助于自身论文的研究，只是为了毕业。。

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提示：以下是本篇文章正文内容，下面案例可供参考

一、函数

1.色彩空间转换

void cvCvtColor( const CvArr* src, CvArr* dst, int code );

src：源图像（输入的 8-bit , 16-bit 或 32-bit 单倍精度浮点数影像）
dst：目标图像（输入的 8-bit , 16-bit 或 32-bit 单倍精度浮点数影像）
code：色彩转换
CV_BGR2BGRA、CV_RGB2BGRA、CV_BGRA2RGBA、CV_BGR2BGRA、CV_BGRA2BGR
CV_RGB2GRAY、CV_GRAY2RGB、CV_RGBA2GRAY、CV_GRAY2RGBA
CV_BGR2HSV、CV_RGB2HSV、CV_HSV2BGR、CV_HSV2RGB
CV_BGR2HLS、CV_RGB2HLS、CV_HLS2BGR、CV_HLS2RGB

void OpenCV_quick_day01Demo::colorSpacedDemo(Mat &image) {
	Mat gray, hsv;

	//色彩空间转换，转灰度图，转hsv
	cvtColor(image, gray, COLOR_BGR2GRAY);
	cvtColor(image, hsv, COLOR_BGR2HSV);
	//H 0-180  S,V 0-255,  H,S表示颜色， V表示亮度
	namedWindow("gray", WINDOW_FREERATIO);
	imshow("gray", gray);

	namedWindow("hsv", WINDOW_FREERATIO);
	imshow("hsv", hsv);

2.操作Mat对象；

void OpenCV_quick_day01Demo::creatMatDemo(Mat &image) {
	Mat m1, m2, m3, m4;
	//对于Mat，复制图像，复制了一个对象
	//复制图像-克隆
	m1 = image.clone();
	imshow("m1", m1);
	//复制图像-复制
	image.copyTo(m2);
	imshow("m2", m2);
	//对于Mat，对图像赋值，只是创建指针指向同一个对象
	//赋值
	m3 = image;
	imshow("m3", m3);

	//创建空白图像
	//Mat::zeros 赋值为0
	m4 = Mat::zeros(Size(8, 8), CV_8UC3);//创建8x8图像， CV_8UC1表示单通道 CV_8UC2双通道，CV_8UC3表示三通道等；
	std::cout << "width:" << m4.cols << " height:" << m4.rows
		<< " channels:" << m4.channels() << std::endl;
	std::cout << m4 << std::endl;
	//Mat::ones 对第一通道赋值为1
	Mat m5 = Mat::ones(Size(8, 8), CV_8UC3);
	std::cout << "width:" << m5.cols << " height:" << m5.rows
		<< " channels:" << m5.channels() << std::endl;
	std::cout << m5 << std::endl;

	//Scalar(x,x,x)对mat各个通道赋值为X
	Mat m6 = Mat::zeros(Size(8, 8), CV_8UC3);
	m6 = Scalar(127, 127, 127);
	std::cout << "width:" << m6.cols << " height:" << m6.rows
		<< " channels:" << m6.channels() << std::endl;
	std::cout << m6 << std::endl;

}

3.opencv中图像像素读写操作

void OpenCV_quick_day01Demo::pixelVisitDemo(Mat &image) {
	int w = image.cols;
	int h = image.rows;
	int channel = image.channels();

	//基于数组下标操作图像像素
	/*for (int col = 0; col < w ; col++)
	{
		for (int row = 0; row < h; row++)
		{
			if (channel == 1)//灰度图像操作
			{
				int pv = image.at(row, col);
				image.at(row, col) = 255 - pv;
			}
			else if (channel == 3)//彩色图像
			{
				Vec3b bgr = image.at(row, col);
				image.at(row, col)[0] = 255 - bgr[0];
				image.at(row, col)[1] = 255 - bgr[1];
				image.at(row, col)[2] = 255 - bgr[2];

			}
		}

	}
	imshow("piexlVisit", image);*/

	//基于指针操作图像像素
	for (int row = 0; row < h; row++)
	{
		uchar *current_row = image.ptr<uchar>(row);
		for (int col = 0; col < w; col++)
		{
			if (channel == 1)//灰度图像操作
			{
				int pv = *current_row;
				*current_row++ = 255 - pv;
			}
			else if (channel == 3)//彩色图像
			{
				*current_row++ = 255 - *current_row;
				*current_row++ = 255 - *current_row;
				*current_row++ = 255 - *current_row;

			}
		}
	}
	imshow("piexlVisitPtr", image);

}

4.opencv自带的颜色表操作

 void OpenCV_quick_day01Demo::color_style_demo(Mat &image) {
	 namedWindow("颜色风格", WINDOW_AUTOSIZE);
	 int colorMap[] = { COLORMAP_AUTUMN,COLORMAP_BONE,COLORMAP_CIVIDIS,COLORMAP_COOL,
		 COLORMAP_DEEPGREEN,COLORMAP_HOT,COLORMAP_HSV,COLORMAP_INFERNO,COLORMAP_INFERNO,
		 COLORMAP_JET,COLORMAP_MAGMA,COLORMAP_OCEAN,COLORMAP_PARULA,COLORMAP_PINK,COLORMAP_PLASMA,
		 COLORMAP_RAINBOW,COLORMAP_SPRING,COLORMAP_SUMMER,COLORMAP_TURBO,COLORMAP_TWILIGHT,
		 COLORMAP_TWILIGHT_SHIFTED,COLORMAP_VIRIDIS,COLORMAP_WINTER };

	 Mat  dst;
	 int index = 0;
	 while (true) {
		 int c = waitKey(1000);
		 if (c == 27) {
			 break;
		 }
		 applyColorMap(image, dst, colorMap[index % 23]);
		 index++;
		 imshow("颜色风格", dst);
	 }
	 
 }

4.图像的逻辑操作，即位操作

void OpenCV_quick_day01Demo::bitwise_demo(Mat &image) {
	 Mat m1 = Mat::zeros(Size(256, 256), CV_8UC3);
	 Mat m2 = Mat::zeros(Size(256, 256), CV_8UC3);

	 rectangle(m1, Rect(100, 100, 100, 100), Scalar(255, 255, 0), -1, LINE_8, 0);
	 rectangle(m2, Rect(150, 150, 100, 100), Scalar(0, 255, 255), -1, LINE_8, 0);
	 imshow("m1", m1);
	 imshow("m2", m2);
	 Mat dst;
	 bitwise_and(m1, m2, dst);
	 imshow("与操作", dst);
	 bitwise_or(m1, m2, dst);
	 imshow("或操作", dst);
	 bitwise_not(m1, dst);
	 imshow("非操作", dst);
	 bitwise_xor(m1, m2, dst);
	 imshow("异或操作", dst);
 }