How to draw a line on an image in OpenCV?

Question

If I have the polar coordinates of a line, how can I draw it on an image in OpenCV & python?

Line function takes 2 points, but draws only the segment. I want to draw a line from one edge of the image to other.

Answer 1

Just calculate for 2 points outside. opencv's Line is fine with e.g. (-10,-10) for a point.

import cv2  # python-opencv import numpy as np  width, height = 800, 600 x1, y1 = 0, 0 x2, y2 = 200, 400 image = np.ones((height, width)) * 255  line_thickness = 2 cv2.line(image, (x1, y1), (x2, y2), (0, 255, 0), thickness=line_thickness) 

http://docs.opencv.org/2.4/modules/core/doc/drawing_functions.html#cv2.line