Life2Coding
How to Save OpenCV Image to a File in Python

This post will be helpful in learning OpenCV using Python programming. Here I will show how to implement OpenCV functions and apply it in various aspects using some examples. Then the output will be shown with some comparisons as well.

Requirements:

First, you need to setup your Python Environment with OpenCV. You can easily do it by following Life2Coding’s tutorial on YouTube: Linking OpenCV 3 with Python 3

Goals:

In this tutorial, I will show you how to save OpenCV output image to a file.

Documentation:

Python: cv2.imwrite(filename, img[, params]) → retval

Saves an image to a specified file.

Parameters:   

  • filename – Name of the file.
  • image – Image to be saved.
  • params
    • Format-specific save parameters encoded as pairs paramId_1, paramValue_1, paramId_2, paramValue_2, …. The following parameters are currently supported:
      • For JPEG, it can be a quality (CV_IMWRITE_JPEG_QUALITY) from 0 to 100 (the higher is the better). Default value is 95.
      • For PNG, it can be the compression level (CV_IMWRITE_PNG_COMPRESSION) from 0 to 9. A higher value means a smaller size and longer compression time. Default value is 3.
      • For PPM, PGM, or PBM, it can be a binary format flag (CV_IMWRITE_PXM_BINARY), 0 or 1. Default value is 1.

 Steps:

  • Load Image using cv2.imread()
  • Display Image using cv2.imshow()
  • Save the output in an image file using cv2.imwrite()
  • Wait for keyboard button press using cv2.waitKey()
  • Exit window and destroy all windows using cv2.destroyAllWindows()

Example Code:

import cv2
import numpy as np

def main():
    
    imgpath = "Hanif.jpg"
    img = cv2.imread(imgpath)

    #display the image
    cv2.imshow('Hanif_Life2Coding', img)

    outpath = "Hanif_Save.jpg"
    #save the image
    cv2.imwrite(outpath, img)

    cv2.waitKey(0)
    #destroy a certain window
    cv2.destroyWindow('Hanif_Life2Coding')

if __name__ == "__main__":
    main()

Output:

2 How to Save OpenCV Image to a File in Python

life2coding_icon [] How to Save OpenCV Image to a File in Python

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