How to flip image with opencv and python( without cv2.flip)

Question

i just want to flip image vertically without cv2.flip(), but output is completely black image. where is my mistake ?

import cv2
import numpy as np


def flipv(imgg):
    for i in range(480):
        img2= np.zeros([480, 640, 3], np.uint8)
        img2[i,:]=imgg[480-i-1,:]

    return img2

img = cv2.imread("foto\\test.jpg", 1)

ads= flipv(img)

cv2.imshow("qw",ads)

cv2.waitKey(0)
cv2.destroyAllWindows()

Answer 1

Simple function to flip images using opencv:

def flip(img,axes):
    if (axes == 0) :
        #horizental flip
        return cv2.flip( img, 0 )
    elif(axes == 1):
        #vertical flip
        return cv2.flip( img, 1 )
    elif(axes == -1):
        #both direction
        return cv2.flip( img, -1 ) 
bflp = flip(img,-1)
plt.imshow(bflp)