REGION EXTRACTION
Macro: PROREGGRAREX 
Function: Extraction of regions of a graph corresponding to certain criterions. Result placed in an image, the graph is not modified. 
Parameters:
1. Output image plane.
2. User defined criterions:
-- node number
-- region size to consider
-- minimum no. of neighbours for the region 
-- percentage error admissible for the properties defined by user in this panel.
-- properties to extract

