python 图片缩放到指定像素

python 图片缩放到指定像素

from PIL import Image
import io
import base64

MAX_SIZE = 2450


def resize_image_max_side(image_data: bytes, max_side: int = MAX_SIZE) -> bytes:
    """
    图片缩放
    :param image_data:
    :param max_side:
    :return:
    """
    with Image.open(io.BytesIO(image_data)) as img:
        width, height = img.size
        max_dim = max(width, height)
        if max_dim > max_side:
            scale = max_side / max_dim
            new_size = (int(width * scale), int(height * scale))
            img = img.resize(new_size, Image.LANCZOS)

            output = io.BytesIO()
            if img.mode == 'RGBA':
                # PNG 支持透明通道
                img.save(output, format='PNG')
            else:
                # 确保非 RGBA 模式转为 RGB 再保存为 JPEG
                if img.mode != 'RGB':
                    img = img.convert('RGB')
                img.save(output, format='JPEG')
            return output.getvalue()
    return image_data


def process_image_segmentation(photo_data: bytes):
    """
    公共图像抠图处理逻辑
    :param photo_data: 原图二进制数据
    :param photo_type: 处理类型：matting or commonseg
    :param user_id: 当前用户 ID
    :return: dict 结果数据
    """

    photo_data = resize_image_max_side(photo_data, max_side=2450)


if __name__ == '__main__':
    # 方法1： 通过request 的形式获取图片
    request = ""
    photo = request.files.get("photo")  # 通过request 的形式获取图片
    photo_data = photo.read()
    process_image_segmentation(photo_data)

    # 方法2:  通过base64 的形式获取图片
    photo_base64 = ""
    if photo_base64.startswith('data:image/'):
        splits = photo_base64.split('base64,', 1)
        if len(splits) == 2:
            photo_base64 = splits[1]
    photo_data = base64.b64decode(photo_base64)
    process_image_segmentation(photo_data)