In this tutorial, we will introduce how to remove image noise using contraharmonic mean filter in python opencv.

1.Open an image with noise

import numpy as np
import cv2
#read noise image
img_src = cv2.imread('sample.jpg')

2.Generate contraharmonic mean filter kernel

def contraharmonic_mean(img, size, Q):
    num = np.power(img, Q + 1)
    denom = np.power(img, Q)
    kernel = np.full(size, 1.0)
    result = cv2.filter2D(num, -1, kernel) / cv2.filter2D(denom, -1, kernel)
    return result

3.Implement contraharmonic  mean filter to remove noise in image

cv2.imshow(contraharmonic_mean(img_src, (3,3), 0.5))

Run this code, you may get this image: