Opencv learning notes-day5 (arithmetic operation of image pixels, add() addition function, subtract() subtraction function, divide() division function, multiply() multiplication function

day5- Arithmetic operation of image pixels

function

1. Operator

‘+’ ‘-’ ‘*’ ‘/’
example 1

Mat dst;
dst = image + Scalar(50, 50, 50);
// to image Add... To each pixel 50
dst = image - Scalar(50, 50, 50);// reduce 50
dst = image / Scalar(2, 2, 2);// Divide 50
// Multiplication is usually done with functions 

2. Operator functions

Function requires addition （ reduce , ride , except ） The two images of have the same size , And the pixel type is the same .

Parameters	explain
src1	The first input array
src2	Second and src1 An input array of the same size and type .
dst	The size and type of the output array are the same as src2 identical
scale	Scalar factor
src2	Second and src1 An input array of the same size and type .
dtype	The type of the output array is optional ; If -1,dst There will be depth src2.depth(),
	But in the case of array partitioning , When src1.depth()==src2.depth() when , Can only be passed -1.

1. multiply();// Multiplication function  multiply( The first image , Second image , Output image )

CV_EXPORTS_W void multiply(InputArray src1, InputArray src2,OutputArray dst, double scale = 1, int dtype = -1);

2. add(image,m,dst);// Addition function 

void add(InputArray src1, InputArray src2, OutputArray dst, InputArray mask=noArray(), int dtype=-1);

4. subtract(image,m,dst);// Subtraction function 

void subtract(InputArray src1, InputArray src2, OutputArray dst, InputArray mask=noArray(), int dtype=-1);

5. divide(image, m, dst);// Division function 

void divide(InputArray src1, InputArray src2, OutputArray dst,double scale=1, int dtype=-1);

Code

#include <opencv2\highgui.hpp>

#include <opencv2\imgproc.hpp>

#include<quickopencv.h>

#include <iostream>
void QuickDemo::operators_demo(Mat &image)
{
    
	Mat dst;
	namedWindow(" Original picture ", WINDOW_NORMAL);
	imshow(" Original picture ", image);// Show results 1
	//dst = image + Scalar(50, 50, 50);// to image Add... To each pixel 50-- Show results 2
	//dst = image - Scalar(50, 50, 50);// reduce 50-- Show results 3
	//dst = image / Scalar(2, 2, 2);// Divide 50-- Show results 4

	// Multiplication 
	Mat m = Mat::zeros(image.size(),image.type());
	m=Scalar(2, 2, 2);
	multiply(image,m,dst);// Multiplication function  multiply( The first image , Second image , Output image )-- Show results 5
	add(image,m,dst);// Addition function 
	subtract(image,m,dst);// Subtraction function 
	divide(image, m, dst);// Division function 

	namedWindow("... operation ", WINDOW_NORMAL);
	imshow("... operation ", dst);
}//operators_demo

Show results 1

Show results 2

Show results 3

Show results 4

Show results 5