CODEWITHSUNDEEP
c++opencvmatrixvectordivision
user27665
user27665

Reputation: 683

opencv matrix division by scalar produces very large/small numbers

I take a RGB image. I try to convert it to a vector(code is as below). When I read the vector I get very large or very small values. I think this is something to do with the vector returned from the function but I cant figure it out. I get values like: 2.36943e-38 2.36943e-38 -8256.25 -81920 etc.

#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/opencv.hpp>
#include <opencv2/highgui/highgui_c.h>
#include <iostream>
#include <string>
#include <vector>


using namespace cv;
using namespace std;

vector<float> mat_to_vec(Mat M){
    vector<float> array_temp;

    for (int i=0;i<M.cols;i++){
    for(int j=0;j<M.rows;j++)
    {
        array_temp.push_back(M.at<float>(j,i));
    }  
}
return array_temp;
}


int main(int argc, char** argv)
{

// read the image

Mat src=imread(argv[1],CV_LOAD_IMAGE_COLOR);

// separate the channels 

Mat bgr[3];   //destination array
split(src,bgr);//split source 

// convert to individual arrays and divide by 256
Mat temp_b=bgr[0]/256.0;
Mat temp_g=bgr[1]/256.0;
Mat temp_r=bgr[2]/256.0;

vector<float> array_b=mat_to_vec(temp_b);
vector<float> array_g=mat_to_vec(temp_g);
vector<float> array_r=mat_to_vec(temp_r);

// merge the arrays 

vector<float> array_rgb;
array_rgb.insert(array_rgb.end(), array_r.begin(), array_r.end());
array_rgb.insert(array_rgb.end(), array_g.begin(), array_g.end());
array_rgb.insert(array_rgb.end(), array_b.begin(), array_b.end());

for (int i=0; i<array_rgb.size();i++){
cout << array_rgb[i] << endl;
}
return 0;    
}

Upvotes: 0

Views: 829

Answers (1)

Andrey Smorodov
Andrey Smorodov

Reputation: 10852

You need to convert your src image to float element type image, use src.convertTo(src,CV_32FC1);

Upvotes: 1

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