Untitled

Sum of each column opencv
int imgStep = image->widthStep;
uchar* imageData = (uchar*)image->imageData;
uint result[image->width];
memset(result, 0, sizeof(uchar) * image->width);
for (int col = 0; col < image->width; col++) {
  for (int row = 0; row < image->height; row++) {
    result[col] += imageData[row * imgStep + col];
  }
}

// your desired vector is in result

CvMat * MyMat = cvCreateMat(height, width, CV_64FC1);
// Fill in MyMat with some data...

CvMat * ColSum = cvCreateMat(1, MyMat->width, CV_64FC1);
cvReduce(MyMat, ColSum, 0, CV_REDUCE_SUM);