How to create a Mat on OpenCV for making an histogram

Vote count:

0

I'm making kind of an histogram stored in a Matrix on OpenCV.

So, if I match one result, I will at +1 on some index.

My mat is:

Mat countFramesMatrix = Mat::zeros(9,9,CV_8U);

when I try to access to sum +1 to the already set index (from 0), I do:

int valueMatrixFrames = countFramesMatrix.at<int>(sliceMatch.j, sliceMatch.i);
valueMatrixFrames++;
countFramesMatrix.at<unsigned char>(sliceMatch.j, sliceMatch.i) = (unsigned char)valueMatrixFrames;

I tried in other ways, as changing unsigned char for int an other problems I had before, but nothing happens.

My results are:

1. Or all the matrix is zeros.


2. 
   

   Or I get something like:

   
   

   [2.3693558e-38, 0, 0, 0, 0, 0, 0, 0, 0; 2.3693558e-38, 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0, 0]

   
   

And I'm never storing data at (0,0) or (0,1) or (1,0) or (1,1), :(

What would you suggest? thank you.

asked 2 mins ago

Rafa Firenze

93

How to create a Mat on OpenCV for making an histogram