Drawing polygon

#program to draw polygon
import cv
image=cv.CreateImage((400,400),cv.IPL_DEPTH_8U,1)
vertices = [ (10,10),(100,40),(200,200),(70,250) ]

#   Draw the polygon and fill inside with white color so you get a binary image.
cv.FillConvexPoly(image,vertices,255)

# Now access all points inside polygon and find percentage of white pixels

points = []
white = 0
for i in range(image.height):
    for j in range(image.width):
        if (cv.Get2D(image,j,i)[0]== 255.0):
            points.append([j,i])
            white = white + 1

print "no of white pixels =",white
area = (white*100)/(image.height*image.width)
print "percentage area of tetragon =",area
print points
while(1):
    cv.ShowImage("image",image)
    if cv.WaitKey(0)==27:
        break