Find all maximums for Mat() in OpenCV C++

I want to find all maximums (numbers of non-zero pixels) for my image. I need it to divide my picture such way:

So, i already asked question, how to project all image to one of the axis, and now i need to find all maximums on this one-row image. Here's my part of the code:

void segment_plate (Mat input_image) {
    double minVal; 
    double maxVal; 
    Point minLoc; 
    Point maxLoc;
    Mat work_image = input_image;
    Mat output;
    //binarize image
    adaptiveThreshold(work_image,work_image, 255, ADAPTIVE_THRESH_MEAN_C, THRESH_BINARY, 15, 10);  
    //project it to one axis
    reduce(work_image,output,0,CV_REDUCE_SUM,CV_32S);

    //find minimum and maximum falue for ALL image
    minMaxLoc(output, &minVal,&maxVal,&minLoc,&maxLoc);
    cout << "min val : " << minVal << endl;
    cout << "max val: " << maxVal << endl;

As you can see, i could find one maximum and one minimum for all picture, but i need to find local maximums. Thanks for any help!