c++ - filling contours with opencv python

Question

I have binary image with polylines created with:

cv2.polylines(binaryImage,contours,1, (255,255,255))

What I need now is effective method to fill all polylines. I haven't found such method in opencv, but maybe it exists. Alternatively, maybe I could implement algorithm to do the job (but fast one- I have HD ready pictures). Please share your thoughts..

Answer 1

I think what you are looking for is cv2.fillPoly, which fills the area bounded by one or more polygons. This is a simple snippet, I generate a contour of four points representing vertices of a square, then I fill the polygon with a white color.

import numpy as np
import cv2

contours = np.array( [ [50,50], [50,150], [150, 150], [150,50] ] )
img = np.zeros( (200,200) ) #?create a single channel 200x200 pixel black image 
cv2.fillPoly(img, pts =[contours], color=(255,255,255))
cv2.imshow(" ", img)
cv2.waitKey()