Remove dust from an image with IR information in the alpha channel

remove_dust.py

import cv2
import numpy as np
import argparse
from pathlib import Path
import sys



parser = argparse.ArgumentParser(description="Remove dust from an image with IR information in the alpha channel")
parser.add_argument('image',
                       metavar='img',
                       type=str,
                       help='Path to image') 
parser.add_argument('outdir',
                       metavar='out',
                       type=str,
                       default=str,
                       help='Output directory')       
parser.add_argument('-thr',
                       metavar='thr',
                       type=float,
                       default=0.95,
                       help='Percentage of maximum value to threshold the IR mask')  
parser.add_argument('-rad',
                       metavar='rad',
                       type=float,
                       default=0.95,
                       help='Inpainting radius')        
parser.add_argument("--masksweep", help="Outputs a series of masks at different thresholds starting from .85", default=False, action='store_true')
          
args = parser.parse_args()


img = cv2.normalize(cv2.imread(args.image,cv2.IMREAD_UNCHANGED),None, 255,0, cv2.NORM_MINMAX, cv2.CV_8UC1)
rgb_img = img[:,:,:3].astype(np.uint8)
alpha_img = img[:,:,3].astype(np.uint8)
if args.masksweep:
    for threshold in range(85, 100):
        thresh_mask = ((alpha_img < alpha_img.max() * threshold*0.01) * 255).astype(np.uint8)
        cv2.imwrite(args.outdir + "/" + Path(args.image).stem + "_mask-" + str(threshold) + ".tif", thresh_mask)
else:
    thresh_mask = ((alpha_img < alpha_img.max() * args.thr) * 255).astype(np.uint8)
    cleaned = cv2.inpaint(rgb_img, thresh_mask, args.rad, cv2.INPAINT_NS)
    cv2.imwrite(args.outdir + "/" + Path(args.image).stem + "_clean.tif", cleaned)