identify contours in a image which are having same color using opencv or javacv?

Question

This question is related to my previous question in that question I used color image as input and it identify by using line color but I like to know how to identify that kind of image using gray-scale image. This is the gray-scale input image and have to identify

And I need to identify following objects with its positions (x and y coordinates).

Please can some one explain with simple code example to identify those objects and I need to identify connected lines of those objects as well (As shown in following image).

Please be kind enough to explain this using simple code example.

Answer 1

The concept of solution is the same as with previous question - use dilate and erode:

Mat src = imread("input.jpg"), tmp;

cvtColor(src, tmp, CV_BGR2GRAY);
threshold(tmp, tmp, 200, 255, THRESH_OTSU);

Mat element = getStructuringElement(MORPH_RECT, Size(3, 3), Point(1, 1));
dilate(tmp, tmp, element);
erode(tmp, tmp, element);

Result: