How to flip iamge in opencv without library functions in python-CodePudding

I am trying to flip an image in python but cannot use cv2.flip() as per my design brief. Dose anyone has any ideas to help me? Here is my code so far:

import cv2
import numpy as np

img = cv2.imread('img/bozu.png')
img = cv2.resize(img, (512, 512))

Thanks!

CodePudding user response：

You can flip the image like this as well.

import cv2
import numpy as np

img = cv2.imread('img/bozu.png')
img = cv2.resize(img, (512, 512))

# flip vertically
v_flip = img[::-1]

# flip horizontally
h_flip = img[:, ::-1]

# this is bgr to rgb
bgr2rgb = img[:, :, ::-1]

CodePudding user response：

cv2 uses numpy arrays to manipulate images.
Therefore Your img is 2D numpy array. You can use numpy flip method to flip it.

Here is example code snippet:

import cv2
import numpy as np

img = cv2.imread('img/bozu.png')
img = cv2.resize(img, (512, 512))

# Flip image vertically
v_flip = np.flip(img, axis=0)

# Flip image horizontally
h_flip = np.flip(img, axis=1)