Embed and read images from source code

Question

Instead of using imread() to read a file, how to I embed the image to be read in the source code itself? For example GIMP has an option to export an image as a C source or header file. How do I make use of that?

Have a look at the source code that Gimp produces. It's pretty easy to understand. See also http://stackoverflow.com/questions/8875192/explanation-of-header-pixel-in-gimp-created-c-header-file-of-an-xpm-image — ypnos, Jan 06 '14 at 07:23

score 1 · Answer 1 · answered Jan 06 '14 at 07:26

An image is just an array of numbers. OpenCV's Mat constructor can accept a pointer to data: Mat::Mat(int rows, int cols, int type, void* data, size_t step=AUTO_STEP) If your image data is a hard-coded array, you can can use it for initializing a cv::Mat object

score 0 · Accepted Answer · answered Jan 06 '14 at 17:15

You can use this code snippet:

#include <iostream>
#include <vector>
#include <string>
#include <fstream>
#include <opencv2/opencv.hpp>

using namespace cv;
using namespace std;

// uncomment for test
//#include "image.h" 

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

    Mat img=imread("D:\\ImagesForTest\\lena.jpg");
    int w=img.cols;
    int h=img.rows;
    int channels=img.channels();


    ofstream os("image.h");
    os << "int rows=" << h << ";" << endl;
    os << "int cols=" << w << ";" << endl;
    os << "unsigned char d[]={" << endl;

    for(int i=0;i<h;++i)
    {
        for(int j=0;j<w;++j)
        {   

            if(i!=(w-1) || j!=(h-1))
            {
                Vec3b b=img.at<Vec3b>(i,j);
                os << format("0x%02x,",b[0]);
                os << format("0x%02x,",b[1]);
                os << format("0x%02x,",b[2]);
            }
        }
    }

     Vec3b b=img.at<Vec3b>(w-1,h-1);
     os << format("0x%02x,",b[0]);
     os << format("0x%02x,",b[1]);
     os << format("0x%02x",b[2]);
     os <<  endl << "};" << endl;

     os << "Mat I=Mat(rows,cols,CV_8UC3,d);" << endl;
    os.close();

// uncomment for test
/*
    namedWindow("I");
    imshow("I",I);
    waitKey();
    return 0;
*/

}

it creates header file image.h that contains an image I.

It assumes that image is color 3 channel image with uchar element type.

Embed and read images from source code

2 Answers2