How to remove scratches from metallographic images using Python-CodePudding

I have the following image to analyze and extract the porosity out of it (black dots).

metallographic image of porous alloy

My issue is that my code might be picking up on the scratches (defects from polishing the cross-sections). I am looking for a way to remove the scratches.

I tried Inpainting (

Result

You can also optionally filter out large/small dots using contour area filtering with a threshold value

import cv2

# Load image, grayscale, Gaussian blur, Otsu's threshold
image = cv2.imread("1.png")
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
blur = cv2.GaussianBlur(gray, (5,5), 0)
thresh = cv2.threshold(blur, 0, 255, cv2.THRESH_BINARY_INV   cv2.THRESH_OTSU)[1]

# OPTIONAL to filter out small/large dots using contour area filtering
# Adjust the area to only keep larger dots
'''
DOT_AREA = 10
cnts = cv2.findContours(thresh, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
cnts = cnts[0] if len(cnts) == 2 else cnts[1]
for c in cnts:
    area = cv2.contourArea(c)
    if area < DOT_AREA:
        cv2.drawContours(thresh, [c], -1, 0, -1)
'''

# Bitwise_and to extract dots
result = cv2.bitwise_and(image, image, mask=thresh)
result[thresh==0] = 255

cv2.imshow("thresh", thresh)
cv2.imshow("result", result)
cv2.waitKey()