プログラム
convert_to_gray.py
#! /usr/bin/python
#
# convert_to_gray.py
#
# May/28/2024
# --------------------------------------------------------------------
import sys
from PIL import Image
# --------------------------------------------------------------------
sys.stderr.write("*** 開始 ***\n")
file_in = sys.argv[1]
file_out = sys.argv[2]
sys.stderr.write(file_in + "\n")
sys.stderr.write(file_out + "\n")
#
aa_jpg = Image.open(file_in,'r')
gray_img = aa_jpg.convert('L')
#
gray_img.save(file_out)
#
width, height = gray_img.size
print(width, height)
#
sys.stderr.write("*** 終了 ***\n")
# --------------------------------------------------------------------
## 実行スクリプト
```bash
./convert_to_gray.py image.jpg gray.jpg