OPENCV Basic Drawing functions

OpenCV commonly used data structures and functions

Color space conversion function Cvtcolor function

The Cvtcolor function is a color space conversion function in OPENCV.
It can convert RGB to HSV HSI and other color space, and can be converted to grayscale image.

Prototype: void Cvtcolor (Inputarray src,outarray dst,int code,int dstcn =0);
SRC: Input image
DST: Output image
Code: Color Conversion Space Indicator
DSTCN: The number of channels of the target image if this parameter is 0 is the number of channels of the target image

Cvtcolor function identifiers
Rgb-> BGR Cv_bgr2bgra, CV_RGB2BGRA,CV_BGRA2RGBA,CV_BGR2BGRA,CV_BGRA2BGR
Rgb->gray Cv_rgb2gray,cv_gray2rgb,cv_rgba2gray,cv_gray2rgba
RGB->HSV Cv_rgb2hsv,cv_bgr2hsv,cv_hsv2bgr,cv_hsv2bgr,cv_hsv2rgb
Rgb->hls CV_RGB2HLS,CV_BGR2HLS,CV_HLS2RGB,CV_HLS2BGR

#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
using namespace CV;
int main ()
{
Mat srcimage = Imread ("Jpg/1.jpeg");
Mat Dstimage;
Cvtcolor (SRCIMAGE,DSTIMAGE,CV_RGB2BGR);
Imshow ("src", srcimage);
Imshow ("DST", dstimage);
Waitkey ();
return 0;
}

Graph drawing function
The use of the ellipse function
Function prototypes: void Ellipse (mat&img, point Center, Size axes, double angle, double startangle, double endangle, const SCALAR& ; color, int thickness=1, int linetype=8, int shift=0)

IMG: Canvas Container
Center: Oval Centre
Axes: The size is in the rectangle
Angle: The angle of rotation of the ellipse
StartAngle: Start Radian
Endangle: End Radian
Color: Graphic Colors
Thickness: line width
Linetype: Linetype
Shift: The precision of the center coordinate points and the axes

#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
using namespace CV;
#define WINDOW_WIDTH 600
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
);

}
int main ()
{
Mat img (1000,600,cv_8uc3,scalar::all (0));
DrawEllipse (img,30);
Imshow ("Ellipse", IMG);
Waitkey ();
return 0;
}

Use of the Circle function

function prototype void Circle (mat& img, point Center, int radius, const scalar& color, Intthickness=1, int linetype=8, int shif t=0)
IMG: The image that will be drawn round;
Center: Center;
Radius: radius;
Color: The colour of the circle;
Thickness: If the value is positive, the thickness of the outer contour of the circle, if the value is negative, indicates to draw a fill circle;
Linetype: line type;
Shift

void Drawcircle (Mat img)
{
int thickness =-1;
int linetype = 8;

Circle
Img
Point (100,300),
60,
Scalar (0,89,255),
Thickness
Linetype

);
}

The use of the line function
Function prototype line (mat& img, point pt1, point pt2, const scalar& color, int thickness=1, int linetype=8, int shift=0)
IMG: Output image
PT1: Start point
PT2: End point
Color: Line Colors
Thickness: Line Thickness
Linetype: Linetype
Shift

void DrawLine (Mat img)
{
int thickness = 1;
int linetype = 8;

Line
Img
Point (100,200),
Point (500,600),
Scalar (255,23,56),
Thickness
Linetype
);
}

OPENCV Basic Drawing functions