1. Draw some key points for region growing
 Collect the center points and contour points from the extracted contour which is stored in
 a XML data file.
2. Region Growing
 2.1 Set the center point as a seed;
 2.2 Grow the cell from the seed in the way of 4 connectivity neighborhoods till touch certain
 point on contour;
 2.3 Store the pixels’ information into a XML file attributed by position and gray level as tree
 nodes.
3. Continue to calculate cell pixels included in next contour
4. If All cells have been extracted successfully, then exit
5. Else return 1
Algorithm 2: Region growing algorithm.