dividing image horizontally into equal parts

edit

@sturkmen thanks very much.

can you explain the parameters of Rect (topROI and bottomROI)

cv::Rect topROI(0, 0,gray.cols, gray.rows / 2);

cv::Rect bottomROI(0, topROI.height, gray.cols, gray.rows - topROI.height);

I have written the answer, and the remark of @sturkmen (imageInint shoud be a single-channel Mat) is a good one. The parameters are explained in the docs of Rect (Rect is Rect_<int>).

for parameters of cv::Rect bottomROI(0, topROI.height, gray.cols, gray.rows - topROI.height);

       0: is top x  ,

      y: equals to the height of the first half (topROI)

     width : imageInit.cols    (image cols)

    height : image rows - topROI  height

Is that right , Thanks

I tried to display whitePixelsTop and int whitePixelsBottom and calculate the difference

Why I'm getting unhadled exception ? Code

• x = 0 (so col 0 so the leftest col);
• y = topROI.height (so the second half starts after the first, in the meddle row);
• width = image.cols (you take ll the width of the image)
• height = image.rows - topROI.height (the rest of the image; here it should be the same as the topROI.height if the image has an even number of rows)

As mentioned by sturkmen, src is not binary (it is RGB). Do a threshold on it

the image is a single channel and I checked it by image.channels()

also I threshold it threshold(gray, gray_thresh, 50, 255, THRESH_BINARY);

it still throws exception

And do you apply the countNonZero on the gray_thresh image (or a roi of it)?

It is solved now , I passed a one channel image to this function , many thanks for help