Weifa Gan's profile - activity

I observe that when the Mat data,which were loaded from a picture, transform negative value to zero after subtracting by a number.But I don't need this transform,what should i do ?pleace. The codes are as follows.

#include<iostream>
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
using namespace std;
using namespace cv;
int main()
{

        Mat M;
    Point2i p;
    M = imread("D:\\Documents\\Desktop\\Face data\\AR1\\001\\AR001-1.tif", 1);
    cvtColor(M, M, CV_BGR2GRAY);
    M = M - 300;
    cout << M << endl;

      waitKey(0);
    system("pause");
}

Thank you very much!

negative value of cv::Mat I observe that when the Mat data,which were loaded from a picture, transform negative value to

the book of learning opencv3 said that m0.push_back( s ) is used to extend an m × 1 matrix and insert the singleton s at the end while m0.push_back( m1 ) is used to extend an m × n by k rows and copy m1 into those rows; Cloud you tell me what's the different between s and m1 in the term of class?Does the singleton means the a single number?

Thanks your explain!

about push_back the book of learning opencv3 said that m0.push_back( s ) is used to extend an m × 1 matrix and insert th

I don't know how to use the mask. Some problem has occur when i use the following codes,but i don't know why. please help me to understand.thank you!

#include<iostream>
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>

using namespace std;
using namespace cv;
int main()
{
    Mat_<float> m(3, 3);
    m << 1.0f, 2.0f, 3.9f, 4.0f, 5.0f, 6.0f, 7.7f, 8.0f, 9.0f;

    Mat_<int> mask1(3, 3);
    mask1 << 1, 2, 3, 0,1,2,3,0,0;

    Mat m2;
    m.copyTo(m2,mask1);

    cout<< m2 << endl;

       system("pause");
}

Yeah,Thanks a lot.And how do you know that?

The problem of the mask? I don't know how to use the mask. Some problem has occur when i use the following codes,but i d

The problem of the mask? I don't know how to use the mask. Some problem has occur when i use the following codes,but i d

I want to set the iterator to the specified element of the matrix, but the output is nothing or messy code. The codes are following. pleace help me to understand.Thank you!

#include<iostream>
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>

using namespace std;
using namespace cv;
int main()
{

    Point2i pi(0,0);
    Mat n=(Mat_<float>(2,2) << 1.0f, 2.0f, 3.0f, 4.0f);
    Mat* m=& n;
    MatConstIterator ito(m, pi);
    cout <<(*ito);
    system("pause");

}

Thanks! But it still have some problem,reminding that the constructors do not match the parameter list. Does MatConst

Thanks! But it still have some problem,reminding that the constructors do not match the parameter list. Does MatConst

question of using iterator I want to set the iterator to the specified element of the matrix, but the output is nothing

thanks your guidance!

Yeah.Thank you very much! how do you know typo? and MatConstIterator_<vec3f> it = m.begin<vec3f>() what mean

Yeah.Thank you very much! and how do you know that? MatConstIterator_<vec3f> it = m.begin<vec3f>() what mean

Yeah.Thank you very much! and how do you know that?

I am new learner for opencv,so i wan to ask some question about it. I type some codes, which can find in the book learning opencv3 ,but error has occur when i use the CV::MatConstlerator. The error is that it is not contain a list of template parameters .It make me confused. Pleace help to understand.Thank you very much.

codes are as followed:

#include"iostream"
#include"opencv2/core/core.hpp"
#include"opencv2/highgui/highgui.hpp"

using namespace std;
using namespace cv;
int main()
{

    int sz[3] = { 4,4,4 };
    Mat m(3, sz, CV_32FC3);
    randu(m, -1.0f, 1.0f);

    float mat = 0.0f;
    MatConstIterator<Vec3f>it = m.begin();



    system("pause");
}

Yeah.Thank you very much! but how do you know that?

Question of using CV::MatConstIterator I am new learner for opencv,so i wan to ask some question about it. I type some c

Question of using CV::MatConstIterator I am new learner for opencv,so i wan to ask some question about it. I type some c

Question of using CV::MatConstIterator I am new learner for opencv,so i wan to ask some question about it. I type some c

Question of using CV::MatConstIterator I am new learner for opencv,so i wan to ask some question about it. I type some c

Question of using CV::MatConstIterator I am new learner for opencv,so i wan to ask some question about it. I type some c

Question of using CV::MatConstIterator I am new learner for opencv,so i wan to ask some question about it. I type some c

Question of using CV::MatConstIterator I am new learner for opencv,so i wan to ask some question about it. I type some c

Great! Thanks your help.

I am a new learner for opencv. When I want to reshape m33f to m91f, it will be error due to no "typedef Matx<float,9,1> Matx91f". Then what shoud i do ?pleace help me to deal with the problem. Thank you in advance. .

Question of Reshaping a matrix I am a new learner for opencv. When I want to reshape m33f to m91f, it will be error due

Question of Reshaping a matrix I am a new learner for opencv. When I want to reshape m33f to m91f, it will be error due

Question of Reshaping a matrix I am a new learner for opencv. When I want to reshape m33f to m91f, it will be error due

Question of Reshaping a matrix I am a new learner for opencv. When I want to reshape m33f to m91f, it will be error due

Question of Reshaping a matrix I am a new learner for opencv. When I want to reshape m33f to m91f, it will be error due

Question of Reshaping a matrix I am a new learner for opencv. When I want to reshape m33f to m91f, it will be error due

Question of Reshaping a matrix I am a new learner for opencv. When I want to reshape m33f to m91f, it will be error due

Question of Reshaping a matrix I am a new learner for opencv. When I want to reshape m33f to m91f, it will be error due

Question of Reshaping a matrix I am a new learner for opencv. When I want to reshape m33f to m91f, it will be error due

I am sorry for regarding " , " as " . ".