python 设置图片的DPI、颜色模式（RGB/CMYK）

使用了Python的Pillow库

import sys
from PIL import Image
Image.MAX_IMAGE_PIXELS = 2000000000

def convert_image_to_jpg(input_path, output_path, dpi=300, color_mode = 'RGB'):
    with Image.open(input_path) as img:
        # 设置DPI
        img.info['dpi'] = (dpi, dpi)
        # 保存为JPG格式，并设置优化参数
        img.convert(color_mode).save(output_path, 'JPEG', quality=100, dpi=(dpi, dpi), optimize=True)


if len(sys.argv) < 2:
    print("需要传入两个地址")
    sys.exit(1)

png_path = sys.argv[1]
jpg_path = sys.argv[2]
dpi = int(sys.argv[3])

if (len(sys.argv) < 3):
    print("至少需要传入三个参数")
    sys.exit(1)

color_mode = 'RGB'
if (len(sys.argv) >= 5):
    color_mode = sys.argv[4]

if (png_path == ""):
    print("png_path需要传入")
    sys.exit(1)

if (jpg_path == ""):
    print("jpg_path需要传入")
    sys.exit(1)

if (dpi == 0):
    print("dpi需要传入")
    sys.exit(1)

# 使用函数转换图片
convert_image_to_jpg(png_path, jpg_path, dpi, color_mode)


# 命令行执行示例
# python3 /www/web/py/jpgdpi.py 'a.png' 'b.jpg' 300 'CMYK'

开始没有设置像素处理极限，有警告错误

/usr/local/python3/lib/python3.8/site-packages/PIL/Image.py:3011: DecompressionBombWarning: Image size (114276962 pixels) exceeds limit of 89478485 pixels, could be decompression bomb DOS attack.
  warnings.warn(
^CTraceback (most recent call last):
  File "/www/web/py/jpgdpi.py", line 12, in <module>
    convert_image_to_jpg('XXX_.png', 'XXX.jpg')
  File "/www/web/py/jpgdpi.py", line 9, in convert_image_to_jpg
    img.convert('RGB').save(output_path, 'JPEG', quality=95, dpi=(dpi, dpi), optimize=True)
  File "/usr/local/python3/lib/python3.8/site-packages/PIL/Image.py", line 934, in convert
    self.load()
  File "/usr/local/python3/lib/python3.8/site-packages/PIL/ImageFile.py", line 257, in load
    n, err_code = decoder.decode(b)
KeyboardInterrupt

 

设置为20亿像素进行处理，可以成功，设置为none表示不限制，但不建议这种无设置极限的逻辑。