Crop an image/dir of images from CLI

crop.py

#!/usr/bin/env python3
import subprocess
import sys
import argparse

parser = argparse.ArgumentParser(description='Crop an image.')
parser.add_argument('image', metavar='image', type=str, help='the image to crop')
parser.add_argument('left', metavar='left', type=int, help='the left side to crop')
parser.add_argument('right', metavar='right', type=int, help='the right side to crop')
parser.add_argument('top', metavar='top', type=int, help='the top side to crop')
parser.add_argument('bottom', metavar='bottom', type=int, help='the bottom side to crop')
parser.add_argument('-o', '--output', metavar='output', type=str, help='the output file')
args = parser.parse_args()

# check if imagemagick is installed
try:
    subprocess.check_output(["identify", "-version"])
except:
    print("Please install imagemagick.")
    sys.exit()

# arrange the output file's name and path
img_base = args.image[:args.image.rfind(".")]
#extension = args.image[args.image.rfind("."):]
extension = ".png"
path = args.image[:args.image.rfind("/")]
img_out = img_base+"[cropped]"+extension if args.output == None else args.output

# get the current image' size
data = subprocess.check_output(["identify", args.image]).decode("utf-8").strip().replace(args.image, "")
size = [int(n) for n in data.replace(args.image, "").split()[1].split("x")]

# calculate the command to resize
w = str(size[0] - args.left - args.right)
h = str(size[1] - args.top - args.bottom)
x = str(args.left)
y = str(args.top)

# execute the command
cmd = ["convert", args.image, "-crop", f"{w}x{h}+{x}+{y}", "+repage", img_out]
subprocess.Popen(cmd)

crop_directory.sh

#!/bin/bash
# Description: Crop all images in a directory

if [ "$#" -ne 6 ]; then
    echo "Usage: ./crop_dir.sh {directory} {output_directory} {left} {right} {top} {bottom}"
    exit 1
fi

directory="$1"
output_directory="$2"
left="$3"
right="$4"
top="$5"
bottom="$6"

mkdir -p "$output_directory"

find "$directory" -name "*.png" -maxdepth 1 -type f | while IFS= read -r f
do 
    echo "$f"
    python3 crop.py "$f" "$left" "$right" "$top" "$bottom" -o "$output_directory/$(basename "${f}")"
done