My code is the same as this [tutorial](http://docs.opencv.org/master/d2/dbd/tutorial_distance_transform.html#gsc.tab=0).
When I see the result image after using `cv::watershed()`, there is a object(upper-right) that I want to find out, but it's missing. 
There are indeed six marks in image after using `cv::drawContours()`. 
Is this normal because the inaccuracy of the watershed algorithm exist?

Here is part of my code:

```
Mat src = imread("result01.png");

Mat gray;
cvtColor(src, gray, COLOR_BGR2GRAY);

Mat thresh;
threshold(gray, thresh, 0, 255, THRESH_BINARY | THRESH_OTSU);

// noise removal
Mat kernel = Mat::ones(3, 3, CV_8UC1);
Mat opening;
morphologyEx(thresh, opening, MORPH_OPEN, kernel, Point(-1, -1), 2);

// Perform the distance transform algorithm
Mat dist_transform;
distanceTransform(opening, dist_transform, CV_DIST_L2, 5);

// Normalize the distance image for range = {0.0, 1.0}
// so we can visualize and threshold it
normalize(dist_transform, dist_transform, 0, 1., NORM_MINMAX);

// Threshold to obtain the peaks
// This will be the markers for the foreground objects
Mat dist_thresh;
threshold(dist_transform, dist_thresh, 0.5, 1., CV_THRESH_BINARY);

Mat dist_8u;
dist_thresh.convertTo(dist_8u, CV_8U);

// Find total markers
vector<vector<Point> > contours;
findContours(dist_8u, contours, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE);

// Create the marker image for the watershed algorithm
Mat markers = Mat::zeros(dist_thresh.size(), CV_32SC1);

// Draw the foreground markers
for (size_t i = 0; i < contours.size(); i++)
    drawContours(markers, contours, static_cast<int>(i), Scalar::all(static_cast<int>(i)+1), -1);

// Perform the watershed algorithm
watershed(src, markers);

```

Original image:

[![enter image description here](https://i.stack.imgur.com/vaU7E.png)](https://i.stack.imgur.com/vaU7E.png)

Result after `watershed`:

[![enter image description here](https://i.stack.imgur.com/0C9Tx.png)](https://i.stack.imgur.com/0C9Tx.png)

You can find original, intermediate and result image here:

[Result images after specific process](https://drive.google.com/folderview?id=0B0jH44HGZh39X2I4cGtRUXczWWM&usp=sharing)