Opencv 中常見的數(shù)據(jù)結(jié)構(gòu)
1. Mat類
Mat類是用于讀取和保存圖像以及其他矩陣數(shù)據(jù)的數(shù)據(jù)結(jié)構(gòu)，默認(rèn)情況下其尺寸為0.
1.圖像的載入和顯示
// 圖像讀取
//第一個為圖像路徑，第二個是指加載圖像的顏色類型，默認(rèn)為1
Mat img = imread("left_0.png",1);
顏色類型的選?。? >0, 返回一個3通道的彩色圖像
? =0，返回灰度圖像
? <0, 返回包含Alpha通道的加載圖像
// 圖像顯示
imshow("窗口名字", img);
// 圖像保存
imwrite("rectify_left.png", img);
2. Mat初始化方法
Mat的初始化方法主要有以下幾種：
//使用Mat()
Mat M(2,2, CV_8UC3, Scalar(0,0,255));
Mat r = Mat(10,3,CV_8UC3);
//CV_8UC3指的是：CV_ [每一項的位數(shù)] [有符號或無符號] [類型前綴] C [通道數(shù)]
//使用Create()函數(shù)
M.create(4,4, CV_8UC(2));
//MATLAB風(fēng)格初始化，zeros()，ones()，eyes()
//指定使用的尺寸和數(shù)據(jù)類型
Mat E = Mat::eye(4, 4, CV_64F)；
cout << "E = " << endl << " " << E << endl << endl;
Mat O = Mat::ones(2, 2, CV_32F);
cout << "O = " << endl << " " << O << endl << endl;
Mat Z = Mat::zeros(3,3, CV_8UC1);
cout << "Z = " << endl << " " << Z << endl << endl;
//使用已有的Mat對象創(chuàng)建
Mat RowClone = C.row(1).clone();
cout << "RowClone = " << endl << " " << RowClone << endl << endl;
//自定義
Mat array = (Mat_<double>(3, 3) << 0, -1, 5, -1, 5, -1, 0, -1, 0);
3. Mat的拷貝
Mat img;
Mat M;
img.copyTo(M);
//
M = img.clone();
2.常用的數(shù)據(jù)結(jié)構(gòu)和函數(shù)
1.點的表示：Point類
注意 Point_<int>, Point2i、Point互相等價
Point point;
point.x = 0;
point.y = 0;
//
Point point = Point(0,0);
2. Scalar類：顏色的表示
Scalar()是一個具有四個元素的數(shù)組，在OpenCV中被大量用于傳遞像素值，比如RGB顏色。但RGB顏色值為三個參數(shù)，對于Scalar函數(shù)來說，如果用不到第四個參數(shù)，則不需要寫出來。對于下面這行代碼：
Scalar(a, b, c);
那么定義RGB的顏色值，紅色的分量為c，綠色的分量為b，藍(lán)色的分量為a。
?需要注意的一點是，Scalar的源頭是Scalar_類，而Scalar_類是Vec4x的一個變種，我們常用的Scalar類其實就是Scalar_。這也就是為什么很多函數(shù)的參數(shù)輸入可以是Mat，也可以是Scalar。
3. Size類：尺寸的表示
//Size_(_Tp _width, _Tp_height);
//構(gòu)造出的Size的寬度和高度都是5
Size(5,5);
cv::Size sz; //空構(gòu)造
cv::Size2i sz; //2位int型
cv::Size2f sz; //2位float型
cv::Size sz2(sz1); //將sz1拷貝給sz2
cv::Size2f sz(w,h); //賦值構(gòu)造，w和h分別對應(yīng)屬性width和height
sz.width; //取寬度
sz.height; //取高度
4. Rect類：矩形的表示
Rect類的成員變量有x、y、width、height，分別為左上角點的坐標(biāo)和矩形的寬和高
常用的成員函數(shù)有size()返回值為Size；area()返回的是矩形的面積；contains(Point)判斷點是否在矩形內(nèi)；t1()返回的是左上角點坐標(biāo)；br()返回的是右下角的坐標(biāo)。
Rect rect(x、y、width、height);//初始化
Rect rect =rect1 & rect2; //求兩個矩陣的交集
Rect rect=rect1 | rect2; //求兩個矩陣的并集
Rect rectShift =rect + point; //讓矩形進(jìn)行平移操作
Rect rectScale = rect +size; //讓矩形進(jìn)行縮放操作
5. cvtColor() 函數(shù):顏色空間的轉(zhuǎn)換
RGB顏色向HSV、HSI等顏色空間的轉(zhuǎn)換，也可以轉(zhuǎn)化為灰度圖像
//void cvtColor(InputArray src,OutputArray dst, int code, int dstCn=0);
cvtColor(img1,img2, COLOR_GRAY2BGR);
3.其他常見的數(shù)據(jù)項
//定義二維點
Point2f p(6, 2);
cout << "【2維點】p = " << p << ";\n" << endl;
//定義三維點
Point3f p3f(8, 2, 0);
cout << "【3維點】p3f = " << p3f << ";\n" << endl;
//vector與Mat的轉(zhuǎn)換關(guān)系
vector<float> v;
v.push_back(3);
v.push_back(5);
v.push_back(7);
cout << "【基于Mat的vector】shortvec = " << Mat(v) << ";\n"<<endl;
vector<Point2f> points(20);
for (size_t i = 0; i < points.size(); ++i)
points[i] = Point2f((float)(i * 5), (float)(i % 7));
cout << "【二維點向量】points = " << points<<";";
4.基本圖形的繪制
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
using namespace cv;
#define WINDOW_NAME1 "【繪制圖1】" //為窗口標(biāo)題定義的宏
#define WINDOW_NAME2 "【繪制圖2】" //為窗口標(biāo)題定義的宏
#define WINDOW_WIDTH 600//定義窗口大小的宏
void DrawEllipse( Mat img, double angle );//繪制橢圓
void DrawFilledCircle( Mat img, Point center );//繪制圓
void DrawPolygon( Mat img );//繪制多邊形
void DrawLine( Mat img, Point start, Point end );//繪制線段
int main( void )
{
// 創(chuàng)建空白的Mat圖像
Mat atomImage = Mat::zeros( WINDOW_WIDTH, WINDOW_WIDTH, CV_8UC3 );
Mat rookImage = Mat::zeros( WINDOW_WIDTH, WINDOW_WIDTH, CV_8UC3 );
// ---------------------<1>繪制化學(xué)中的原子示例圖------------------------
//【1.1】先繪制出橢圓
DrawEllipse( atomImage, 90 );
DrawEllipse( atomImage, 0 );
DrawEllipse( atomImage, 45 );
DrawEllipse( atomImage, -45 );
//【1.2】再繪制圓心
DrawFilledCircle( atomImage, Point( WINDOW_WIDTH/2, WINDOW_WIDTH/2) );
// ----------------------------<2>繪制組合圖-----------------------------
//【2.1】先繪制出橢圓
DrawPolygon( rookImage );
// 【2.2】繪制矩形
rectangle( rookImage,
Point( 0, 7*WINDOW_WIDTH/8 ),
Point( WINDOW_WIDTH, WINDOW_WIDTH),
Scalar( 0, 255, 255 ),
-1,
8 );
// 【2.3】繪制一些線段
DrawLine( rookImage, Point( 0, 15*WINDOW_WIDTH/16 ), Point( WINDOW_WIDTH, 15*WINDOW_WIDTH/16 ) );
DrawLine( rookImage, Point( WINDOW_WIDTH/4, 7*WINDOW_WIDTH/8 ), Point( WINDOW_WIDTH/4, WINDOW_WIDTH ) );
DrawLine( rookImage, Point( WINDOW_WIDTH/2, 7*WINDOW_WIDTH/8 ), Point( WINDOW_WIDTH/2, WINDOW_WIDTH ) );
DrawLine( rookImage, Point( 3*WINDOW_WIDTH/4, 7*WINDOW_WIDTH/8 ), Point( 3*WINDOW_WIDTH/4, WINDOW_WIDTH ) );
// ---------------------------<3>顯示繪制出的圖像------------------------
imshow( WINDOW_NAME1, atomImage );
moveWindow( WINDOW_NAME1, 0, 200 );
imshow( WINDOW_NAME2, rookImage );
moveWindow( WINDOW_NAME2, WINDOW_WIDTH, 200 );
waitKey( 0 );
return(0);
}
//-------------------------------【DrawEllipse( )函數(shù)】--------------------------------
// 描述：自定義的繪制函數(shù)，實現(xiàn)了繪制不同角度、相同尺寸的橢圓
//-----------------------------------------------------------------------------------------
void DrawEllipse( Mat img, double angle )
{
int thickness = 2;
int lineType = 8;
ellipse( img,
Point( WINDOW_WIDTH/2, WINDOW_WIDTH/2 ),
Size( WINDOW_WIDTH/4, WINDOW_WIDTH/16 ),
angle,
0,
360,
Scalar( 255, 129, 0 ),
thickness,
lineType );
}
//-----------------------------------【DrawFilledCircle( )函數(shù)】---------------------------
// 描述：自定義的繪制函數(shù)，實現(xiàn)了實心圓的繪制
//-----------------------------------------------------------------------------------------
void DrawFilledCircle( Mat img, Point center )
{
int thickness = -1;
int lineType = 8;
circle( img,
center,
WINDOW_WIDTH/32,
Scalar( 0, 0, 255 ),
thickness,
lineType );
}
//-----------------------------------【DrawPolygon( )函數(shù)】--------------------------
// 描述：自定義的繪制函數(shù)，實現(xiàn)了凹多邊形的繪制
//--------------------------------------------------------------------------------------
void DrawPolygon( Mat img )
{
int lineType = 8;
//創(chuàng)建一些點
Point rookPoints[1][20];
rookPoints[0][0] = Point( WINDOW_WIDTH/4, 7*WINDOW_WIDTH/8 );
rookPoints[0][1] = Point( 3*WINDOW_WIDTH/4, 7*WINDOW_WIDTH/8 );
rookPoints[0][2] = Point( 3*WINDOW_WIDTH/4, 13*WINDOW_WIDTH/16 );
rookPoints[0][3] = Point( 11*WINDOW_WIDTH/16, 13*WINDOW_WIDTH/16 );
rookPoints[0][4] = Point( 19*WINDOW_WIDTH/32, 3*WINDOW_WIDTH/8 );
rookPoints[0][5] = Point( 3*WINDOW_WIDTH/4, 3*WINDOW_WIDTH/8 );
rookPoints[0][6] = Point( 3*WINDOW_WIDTH/4, WINDOW_WIDTH/8 );
rookPoints[0][7] = Point( 26*WINDOW_WIDTH/40, WINDOW_WIDTH/8 );
rookPoints[0][8] = Point( 26*WINDOW_WIDTH/40, WINDOW_WIDTH/4 );
rookPoints[0][9] = Point( 22*WINDOW_WIDTH/40, WINDOW_WIDTH/4 );
rookPoints[0][10] = Point( 22*WINDOW_WIDTH/40, WINDOW_WIDTH/8 );
rookPoints[0][11] = Point( 18*WINDOW_WIDTH/40, WINDOW_WIDTH/8 );
rookPoints[0][12] = Point( 18*WINDOW_WIDTH/40, WINDOW_WIDTH/4 );
rookPoints[0][13] = Point( 14*WINDOW_WIDTH/40, WINDOW_WIDTH/4 );
rookPoints[0][14] = Point( 14*WINDOW_WIDTH/40, WINDOW_WIDTH/8 );
rookPoints[0][15] = Point( WINDOW_WIDTH/4, WINDOW_WIDTH/8 );
rookPoints[0][16] = Point( WINDOW_WIDTH/4, 3*WINDOW_WIDTH/8 );
rookPoints[0][17] = Point( 13*WINDOW_WIDTH/32, 3*WINDOW_WIDTH/8 );
rookPoints[0][18] = Point( 5*WINDOW_WIDTH/16, 13*WINDOW_WIDTH/16 );
rookPoints[0][19] = Point( WINDOW_WIDTH/4, 13*WINDOW_WIDTH/16 );
const Point* ppt[1] = { rookPoints[0] };
int npt[] = { 20 };
fillPoly( img,
ppt,
npt,
1,
Scalar( 255, 255, 255 ),
lineType );
}
//-----------------------------------【DrawLine( )函數(shù)】--------------------------
// 描述：自定義的繪制函數(shù)，實現(xiàn)了線的繪制
//---------------------------------------------------------------------------------
void DrawLine( Mat img, Point start, Point end )
{
int thickness = 2;
int lineType = 8;
line( img,
start,
end,
Scalar( 0, 0, 0 ),
thickness,
lineType );
}
