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Image Mirroring with OpenCV

This section explains how to mirror (flip) an image using OpenCV.

Image mirroring is commonly used for: - Data augmentation - Symmetry analysis - Preprocessing for vision algorithms

1. Implementation Principle​

OpenCV provides the cv2.flip() function to flip an image.

cv2.flip(src, flipCode)

Where:

  • src is the input image
  • flipCode determines the flip direction:
    • 0 → vertical flip
    • 1 → horizontal flip
    • -1 → both vertical and horizontal

2. Implementation Effect​

Navigate to the OpenCV working directory:

cd ~/opencv

Run the image mirroring script:

python3 07.image_flip.py
note

Select the image window and press q to exit the program.

Image Mirroring Result

3. Implementation Code​

import cv2

def flip_image(input_path, output_path, flip_code):
    image = cv2.imread(input_path)

    if image is None:
        print("Error: Unable to open image file.")
        return

    flipped_image = cv2.flip(image, flip_code)

    if cv2.imwrite(output_path, flipped_image):
        print(f"Image saved to {output_path}")
        cv2.imshow('Image Preview', cv2.imread(output_path))
        cv2.waitKey(0)
        cv2.destroyAllWindows()
    else:
        print("Error: Unable to save image file.")

flip_image(
    '/home/jetson/opencv/images/hemihex_logo.png',
    '/home/jetson/opencv/images/hemihex_logo_flip.png',
    1
)

4. Code Explanation​

  • cv2.imread() loads the source image
  • cv2.flip() mirrors the image based on the flip code\
  • cv2.imwrite() saves the flipped image
  • Display functions preview the result

Summary​

  • Image mirroring flips an image horizontally or vertically
  • Implemented using cv2.flip()
  • Useful for augmentation and preprocessing
  • Flip direction is controlled by flipCode

Maintained by HemiHex for OpenCV-based image processing workflows.