asc2png.py

import os
import argparse
import shutil

import py7zr
import cv2
import numpy as np


def main():
    parser = argparse.ArgumentParser(
        'Convert asc files to png 16 bits images. To get float precision into integer, all values are multiplied by 6 before saving them as 16bits png.')
    parser.add_argument('-f', '--folder', type=str, help='Folder of .asc files', default='')
    parser.add_argument('--zip', type=str, help='Zipfile containing .asc files', default='')
    parser.add_argument('-o', '--output', type=str, help='Output folder of .png files', default='out/')
    parser.add_argument('--width', type=int, help='Width of the output image')
    parser.add_argument('--height', type=int, help='Width of the output image')
    parser.add_argument('--normalize', action='store_true', help='If present, normalize images before saving.')

    args = parser.parse_args()

    assert bool(args.folder) ^ bool(args.zip), 'Must set either --folder or --zip (not both)'

    i = 0
    step = 50

    if args.folder:
        for filename in os.listdir(args.folder):
            file = os.path.join(args.folder, filename)
            if os.path.join(file):
                asc2png(file, args.output, args.width if args.width else None, args.height if args.height else None)
            i += 1
            if i % step == 0:
                print(i)
    elif args.zip:
        with py7zr.SevenZipFile(args.zip) as z:
            names = [n for n in z.getnames() if n.endswith('.asc')]
            z.extract(targets=names)
            for n in names:
                asc2png(n, args.output, args.width if args.width else None,
                        args.height if args.height else None, args.normalize)
            shutil.rmtree(names[0].split('/')[0])
            i += 1
            if i % step == 0:
                print(i)


def asc2png(filepath, out_folder, width, height, normalize):
    if out_folder and not os.path.isdir(out_folder):
        os.mkdir(out_folder)

    folder = '/'.join(filepath.split('/')[:-1])
    filename = filepath.split('/')[-1].split('.')[0]
    img = np.loadtxt(os.path.join(folder, filename) + '.asc', skiprows=6)
    img[img < 0] = 0

    if width and height:
        img = cv2.resize(img, (width, height))

    if normalize:
        img = ((img - np.min(img)) / (np.max(img) - np.min(img))) * 65535
    else:
        img = (img * 6)

    img_int = img.astype(np.uint16)

    out = os.path.join(out_folder, f'{filename}.png')
    cv2.imwrite(out, img_int)


if __name__ == '__main__':
    main()