OpenCV and JNI Mat passing problem

[Radek Chudziak]

I slightly changed the code of the Tutorial 2 Advanced Mix Java + Native. The C++ code looks as follows

#include <jni.h>
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/features2d/features2d.hpp>
#include <opencv2/video/tracking.hpp>
#include <opencv2/contrib/contrib.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <vector>


using namespace std;
using namespace cv;


extern "C" {
JNIEXPORT void JNICALL Java_com_droidnova_android_tutorial2d_Panel_FindFeatures(JNIEnv* env, jobject thiz, jlong addrGray, jlong addrRgba)
{


    Mat* pMatGr=(Mat*)addrGray;
    Mat* pMatRgb=(Mat*)addrRgba;




    for (int i = 0; i <  pMatRgb.rows; i++) {


    }


}


}

It is not doing anything but I want to iterate through rows of the mat. But here it is a pointer to the mat and I get the following error message: error: request for member 'rows' in 'pMatRgb', which is of non-class type 'cv::Mat*'

How to convert it into Mat so I will be able to run the above code?

[dschaudel]

for (int i = 0; i <  (*pMatRgb).rows; i++)

[peppschmier]

or you can use: i < pMatRgb->rows;

in fact: you have do dereference the pointer at first!