Is it possible to draw a line at center of image

I am doing palm recognition ,I need an image like figure d in the link below,can u tell how to process plz,(i.e)a line drawn at centre of palm http://imgur.com/Y8B0d

[Jan]

Please, Pat, use proper upper/lower case. There is no reason to make the reading harder as necessary. I've fixed the case in this thread.

Do you want to draw a line on the screen or into the pixels of the image? Which thickness should this line have? How do you define the center of the palm?

[Pat]

sir as in figure i want to draw to draw a line on the image,of any thickness,the centre is at centre point of four fingers leaving the index finger