Opencv learning notes -day10 logical operation of image pixels (usage of rectangle function and rect function and bit related operation in openCV)

day10- Logical operation of image pixels

1. Draw a rectangular

function

1. rectangle();

Function is used to draw a rectangle （ box ） Of , Usually used in the marking of pictures

// Definition 1
CV_EXPORTS_W void rectangle(InputOutputArray img, Point pt1, Point pt2,
                          const Scalar& color, int thickness = 1,
                          int lineType = LINE_8, int shift = 0);

Parameters	explain
img	The processed image
pt1	Draw the coordinates of the upper left point of the rectangle
pt2	Draw the coordinates of the lower right point of the rectangle
color	Color Scalar(255,255,0)
thickness	Line width of rectangular box See in detail #FILLED
lineType	Linetype Default LINE_8, See in detail #LineTypes
shift	The number of decimal places in the coordinates of the shift point

example 1
rectangle(img2, Point(j,i), Point(j + img4.cols, i + img4.rows), Scalar(255, 255, 0), 2, 8);

// Definition 2
CV_EXPORTS void rectangle(CV_IN_OUT Mat& img, Rect rec,
const Scalar& color, int thickness = 1,int lineType = LINE_8, 
int shift = 0);

Parameter description
1.

Parameters	explain
img	The processed image
rec	Rect() function
color	Color Scalar(255,255,0)
thickness	Line width of rectangular box
lineType	Linetype Default LINE_8, See in detail #FILLED
shift	The number of decimal places in the coordinates of the shift point

2. Rect() Function is to draw a rectangle in an image

Rect()(int x, int y, int width, int height);
Parameter meaning ：
Rect（ top left corner x coordinate , top left corner y coordinate , The width of the rectangle , The height of the rectangle ）

example 2

rectangle(m1,Rect(100,100,80,80),Scalar(255,255,0),-1,LINE_8,0);

example 3

Rect(100,100,80,80);// Top left coordinates  x,y(100,100) 
//size 80*80

Add ：

// If you create a Rect object rect(100, 50, 50, 100), that rect There will be the following functions ： 
rect.area();     // return rect The area of  5000 
rect.size();     // return rect The size of the  [50 × 100] 
rect.tl();       // return rect The coordinates of the upper left vertex of  [100, 50] 
rect.br();       // return rect The coordinates of the lower right vertex of  [150, 150] 
rect.width();    // return rect Width  50 
rect.height();   // return rect Height  100 
rect.contains(Point(x, y));  // Returns a boolean variable , Judge rect Does it include Point(x, y) spot  
  
// You can also find the intersection and union of two rectangles  
rect = rect1 & rect2;  
rect = rect1 | rect2;  
  
// You can also pan and zoom the rectangle  
rect = rect + Point(-100, 100); // translation , That is, the top left vertex x coordinate -100,y coordinate +100 
rect = rect + Size(-100, 100);  // The zoom , Top left vertex unchanged , Width -100, Height +100 
  
// You can also compare rectangles , Returns a boolean variable  
rect1 == rect2;  
rect1 != rect2; 

2. Bit operation

function

1. bitwise_and(m1, m2, dst);// And

2. bitwise_or(m1, m2, dst);// or

3. bitwise_not(m1,dst);// Not Reverse operation

4. bitwise_xor(m1,m2,dst);// Exclusive or

Code

quickopencv.h

#pragma once

#include <opencv2\highgui.hpp>

#include <opencv2\imgproc.hpp>

using namespace cv;
// Defining classes 
class QuickDemo{
    
public:
	void colorSpace_Demo(Mat &image);// Color space conversion function 2021-12-24
	void mat_creation_demo(Mat &image);//Mat Object and creation 2021-12-27
	void pixel_vist_Demo(Mat &image);// Read and write operation of image pixels 2022-1-3
	void operators_demo(Mat &image);// Arithmetic operation of image pixels 2022-1-4
	void tracking_bar_demo(Mat &image);// Scroll bar operation demonstration 2022-1-7
	void key_demo(Mat &image);// Keyboard response operation 2022-1-12
	void color_style_demo(Mat &image);//OpenCV With color table operation 2022-1-12
	void bitwise_demo(Mat &image);// Bit operation （ Logical operation ）2022-1-17
};

QuickDemo.cpp

#include <opencv2\highgui.hpp>

#include <opencv2\imgproc.hpp>

#include<quickopencv.h>

#include <iostream>

void QuickDemo::bitwise_demo(Mat &image)
{
    
	// Draw a rectangular 
	Mat m1 = Mat::zeros(Size(256, 256), CV_8UC3);
	Mat m2 = Mat::zeros(Size(256, 256), CV_8UC3);
	rectangle(m1,Rect(100,100,80,80),Scalar(255,255,0),-1,LINE_8,0);
	rectangle(m2, Rect(150, 150, 80, 80), Scalar(0, 255, 255), -1, LINE_8, 0);
	imshow("m1", m1);// Show results 1
	imshow("m2", m2);// Show results 2
	// Bit operation 
	Mat dst;
	//bitwise_and(m1, m2, dst);// And 
	// Show results 3
	//bitwise_or(m1, m2, dst);// or 
	// Show results 4
	//bitwise_not(m1,dst);// Not   Reverse operation 
	// Show results 5
	bitwise_xor(m1,m2,dst);// Exclusive or 
	// Show results 6
	imshow(" Pixel bit operation ", dst);
}

OpencvTest.cpp

#include <iostream>
#include <opencv2\highgui.hpp>
#include <opencv2\imgproc.hpp>
#include<quickopencv.h>

using namespace cv;
using namespace std;


int main()
{
    
	QuickDemo qd;
	qd.bitwise_demo(scr);
	waitKey(0);
	return 0;
}

According to the effect

Show results 1

Show results 2

Show results 3

Show results 4

Show results 5

Show results 6