''' Purpose: support image black-and-white transformation
'''

def size( original ) :
    ''' Purpose: return the size of the new image when performing a monotone
        transformation
    '''

    nw, nh = original.size

    return (nw, nh)

def color( opixel ) : 
    ''' Returns a new pixel whose RRB values are either (0, 0, 0) or
        (255, 255, 255).  
        
        Returns (0, 0, 0) if the average of RGB values for opixel is closer 
        to 0 then 255; otherwise, it returns (255, 255, 255)
    '''

    pass

def where( nspot, original = None ) :
    ''' Purpose: return the correspondent of nspot in the original when
            doing a monotone transformation
    '''

    ospot = nspot

    return ospot

if ( __name__ == '__main__' ) :

    import url
    from manip import manip
    
    # get web image of interest
    link = "http://www.cs.virginia.edu/~cs1112/images/mandrill/full.png"

    original = url.get_image( link )

    new_image = manip( original, size, color, where )

    new_image.show()