I’m doing a test with opencv and python but the code below does not return anything.... Some poedria help me see if there is any error?

Question

import numpy as np
import cv2

cap = cv2.VideoCapture('peopleCounter.avi') #Open video file

while(cap.isOpened()):
    ret, frame = cap.read() #read a frame
    try:        
        cv2.imshow('Frame',frame)
        frame2 = frame
    except:
        #if there are no more frames to show...
        print('EOF')
        break

    line1 = np.array([[100,100],[300,100],[350,200]], np.int32).reshape((-1,1,2))
    line2 = np.array([[400,50],[450,300]], np.int32).reshape((-1,1,2))

    frame2 = cv2.polylines(frame2,[line1],False,(255,0,0),thickness=2)
    frame2 = cv2.polylines(frame2,[line2],False,(0,0,255),thickness=1)

    cv2.imshow('Frame 2',frame2)

    #Abort and exit with 'Q' or ESC
    k = cv2.waitKey(30) & 0xff
    if k == 27:
        break

cap.release() #release video file
cv2.destroyAllWindows() #close all openCV windows

The error returned by the console and:

Traceback (most recent call last):
  File "/home/adryan/Documentos/Projects/SPtrans/OpenCV/People-Counter/Drawing_2.0.py", line 22, in <module>
    cv2.imshow('Frame 2',frame2)
error: /build/opencv-00QkEr/opencv-2.4.9.1+dfsg1/modules/highgui/src/window.cpp:261: error: (-215) size.width>0 && size.height>0 in function imshow

Answer 1

    line1 = np.array([[100,100],[300,100],[350,200]], np.int32).reshape((-1,1,2))
    line2 = np.array([[400,50],[450,300]], np.int32).reshape((-1,1,2))

    cv2.polylines(frame,[line1],False,(255,0,0),thickness=2)
    cv2.polylines(frame,[line2],False,(0,0,255),thickness=1)

    cv2.imshow('Frame 2',frame)

There’s a solution for those who have the same problem.