PIL -如何在粘贴的图像中添加圆角？

from PIL import Image, ImageDraw

original_image = Image.open("original_image.jpg")
paste_image = Image.open("paste_image.png")

layer = Image.new("RGBA", original_image.size, (0, 0, 0, 0))

border_radius = 50  # 圆角半径
mask = Image.new("L", original_image.size, 0)
draw = ImageDraw.Draw(mask)
draw.rounded_rectangle((0, 0, original_image.width, original_image.height), border_radius, fill=255)

layer.paste(paste_image, (x, y), mask=mask)

result = Image.alpha_composite(original_image.convert("RGBA"), layer)

result.save("result_image.jpg")