用新版bing生成的调整图片尺寸&加上白色边框

letterbox.py

import os
from PIL import Image

# 定义源目录和目标目录
source_dir = r"D:\dataset\before"
target_dir = r"D:\dataset\after"

# 遍历源目录下的所有图片文件
for filename in os.listdir(source_dir):
    # 打开图片文件
    image = Image.open(os.path.join(source_dir, filename))
    # 获取图片的宽度和高度
    width, height = image.size
    # 计算缩放比例，保持图像比例不变
    ratio = min(512 / width, 512 / height)
    # 计算缩放后的宽度和高度
    new_width = int(width * ratio)
    new_height = int(height * ratio)
    # 缩放图片
    image = image.resize((new_width, new_height), Image.ANTIALIAS)
    # 创建一个新的白色背景图片，大小为512x512
    background = Image.new("RGB", (512, 512), (255, 255, 255))
    # 将缩放后的图片粘贴到背景图片上，居中对齐
    offset_x = (512 - new_width) // 2
    offset_y = (512 - new_height) // 2
    background.paste(image, (offset_x, offset_y))
    # 将背景图片保存到目标目录下，格式为png
    background.save(os.path.join(target_dir, filename + ".png"))