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Flip

Introduction​

This section teaches how to use OpenCV to flip images, supporting flipping along the X-axis or Y-axis to achieve mirroring functionality.

Experiment Objective​

Flip an image and display it.

Experiment Explanation​

The OpenCV Python library provides the flip() function for image flipping.

flip() Usage​

img = cv2.flip(src, flipCode)

Image flipping.

  • src: Original image.
  • flipCode: Flip type.
    • 0: Flip along the X-axis.
    • 1: Flip along the Y-axis.
    • -1: Flip along both the X and Y axes simultaneously.

In this section, we will apply all three flip modes to an image and display the results. The code flow is as follows:


The reference code is as follows:

'''
Experiment Name: Image Flip
Experiment Platform: WalnutPi 1B
'''

import cv2

img = cv2.imread("lenna.jpg") # Read the image lenna.jpg from the current directory
cv2.imshow('lenna', img) # Display the image

img1 = cv2.flip(img, 0) # Flip along the X-axis
cv2.imshow('X', img1) # Display the image

img2 = cv2.flip(img, 1) # Flip along the Y-axis
cv2.imshow('Y', img2) # Display the image

img3 = cv2.flip(img, -1) # Flip along both X and Y axes
cv2.imshow('X & Y', img3) # Display the image

cv2.waitKey() # Wait for any keyboard key to be pressed
cv2.destroyAllWindows() # Close the window

Experiment Results​

Run the above code on the WalnutPi; the experiment results are as shown below (multiple windows may overlap — use the mouse to drag them apart):

flip