Error while working with contours
when running this code
import numpy as np
import cv2
image=cv2.imread('screenshoot10.jpg')
cv2.imshow('input image', image)
gray=cv2.cvtColor(image,cv2.COLOR_BGR2GRAY)
edged=cv2.Canny(gray,30,200)
cv2.imshow('canny edges',edged)
_, contours = cv2.findContours(edged,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_NONE)
cv2.imshow('canny edges after contouring', edged)
print(contours)
print('Numbers of contours found=' + str(len(contours)))
cv2.drawContours(image,contours,-1,(0,255,0),3)
cv2.imshow('contours',image)
cv2.waitKey(0)
cv2.destroyAllWindows()
getting an error
OpenCV(4.1.1) C:\projects\opencv-python\opencv\modules\imgproc\src\drawing.cpp:2509: error: (-215:Assertion failed) npoints > 0 in function 'cv::drawContours'
what am I doing wrong?
You are missing one or two algorithms in order to get
drawContours
working