Divided Image into regions and get the location of a point with respect to that.

Hi guys and thanks in advance. I have the following Image as attached which is divided into Regions (I to VI) Note: Disregard the B-Line. How may I divid the image into region in which each region is difined by the two solid lines. The point of this that I have multiple points that I want to determine which region each point falls in.

[Abdullah Azzam]

If B-line cannot be disregarded it wont matter as I can use other function to combine the region number on the left and right of the B-line.