accessing mat pixels in native

Question

i am trying to access and modify mat pixels in native, but i cannot get rid of errors. my function is:

`extern "C" {
JNIEXPORT void JNICALL Java_org_opencv_samples_tutorial3_Sample3Native_FindFeatures(JNIEnv*, jobject, jlong addrGray, jlong addrRgba)
{
    Mat* pMatGr=(Mat*)addrGray;
    Mat* pMatRgb=(Mat*)addrRgba;
    vector<KeyPoint> v;
int i=0;

uchar* pixel = addrRgba.data;
for(int i = 0; i < Mat.rows * Mat.cols; ++i)
{
    // access pixel[0],pixel[1],pixel[2] here
    pixel += 3; // move to next pixel
}

}

}
`

and it is called by:

FindFeatures(mGrayMat.getNativeObjAddr(), mRgba.getNativeObjAddr());

from java

my errors are

"field 'data' cannot be resolved", "field 'rows' cannot be resolved"

help would be very appreciated. thanks

score 0 · Accepted Answer · answered Nov 13 '12 at 10:20

0

Mat.rows should be pMatGr->rows, Mat.cols should pMatGr->cols, addrRgba.data should be pMatRgb->data.

answered Nov 13 '12 at 10:20

john

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27

Well, I'm not making any promises about that. – john Nov 13 '12 at 10:44
no need to promise, it worked with the corrections you wrote, exept pMatGr should be pMatRgb of course. – user1768360 Nov 13 '12 at 10:47

accessing mat pixels in native

1 Answers1