410dd47c14
- 将 server/, src/, scripts/, test/ 等目录移动到 backend/ 目录下 - 使用 git rename 保留文件历史记录 - 更新 docker-compose.yml 和 api.Dockerfile 配置 WIP: 项目结构重构进行中
208 lines
7.3 KiB
Python
208 lines
7.3 KiB
Python
"""
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图片处理工具模块
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支持图片的格式转换、压缩、缩略图生成等功能
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"""
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import base64
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import io
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from PIL import ExifTags, Image
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from yuxi.utils import logger
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class ImageProcessor:
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"""图片处理类"""
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# 支持的图片格式
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SUPPORTED_FORMATS = {"JPEG", "PNG", "WebP", "GIF", "BMP"}
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# 最大文件大小（5MB）
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MAX_FILE_SIZE = 5 * 1024 * 1024
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# 缩略图尺寸
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THUMBNAIL_SIZE = (200, 200)
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def process_image(self, image_data: bytes, original_filename: str = "") -> dict:
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"""
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处理上传的图片
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Args:
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image_data: 图片二进制数据
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original_filename: 原始文件名
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Returns:
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dict: 包含处理结果的字典
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"""
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try:
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# 验证图片格式
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img_format, _ = self._validate_image_format(image_data)
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if img_format not in self.SUPPORTED_FORMATS:
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raise ValueError(f"不支持的图片格式: {img_format}")
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# 加载图片
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with Image.open(io.BytesIO(image_data)) as img:
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# 处理EXIF方向信息
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img = self._fix_image_orientation(img)
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# 生成缩略图
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thumbnail_data = self._generate_thumbnail(img)
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# 压缩主图片（如果需要）
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processed_data, final_format = self._compress_image(img, img_format)
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# 转换为 base64
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base64_data = base64.b64encode(processed_data).decode("utf-8")
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base64_thumbnail = base64.b64encode(thumbnail_data).decode("utf-8")
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# 获取图片信息
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width, height = img.size
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mime_type = f"image/{final_format.lower()}"
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return {
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"success": True,
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"image_content": base64_data,
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"thumbnail_content": base64_thumbnail,
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"width": width,
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"height": height,
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"format": final_format,
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"mime_type": mime_type,
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"size_bytes": len(processed_data),
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"original_filename": original_filename,
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}
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except Exception as e:
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logger.error(f"图片处理失败: {str(e)}")
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return {"success": False, "error": str(e)}
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def _validate_image_format(self, image_data: bytes) -> tuple[str, str]:
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"""验证图片格式并返回格式信息"""
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try:
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with Image.open(io.BytesIO(image_data)) as img:
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return img.format, img.mode
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except Exception as e:
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raise ValueError(f"无效的图片格式: {str(e)}")
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def _fix_image_orientation(self, img: Image.Image) -> Image.Image:
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"""根据EXIF信息修正图片方向"""
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try:
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if hasattr(img, "_getexif"):
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exif = img._getexif()
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if exif is not None:
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for tag, value in exif.items():
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if tag in ExifTags.TAGS and ExifTags.TAGS[tag] == "Orientation":
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if value == 3:
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img = img.rotate(180, expand=True)
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elif value == 6:
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img = img.rotate(270, expand=True)
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elif value == 8:
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img = img.rotate(90, expand=True)
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break
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except Exception as e:
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logger.warning(f"修正图片方向失败，使用原始方向: {str(e)}")
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return img
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def _generate_thumbnail(self, img: Image.Image) -> bytes:
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"""生成缩略图"""
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try:
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# 创建副本以避免修改原图
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thumbnail = img.copy()
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# 转换为RGB模式（处理RGBA等格式）
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if thumbnail.mode != "RGB":
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thumbnail = thumbnail.convert("RGB")
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# 生成缩略图，保持宽高比
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thumbnail.thumbnail(self.THUMBNAIL_SIZE, Image.Resampling.LANCZOS)
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# 转换为JPEG格式
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with io.BytesIO() as output:
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thumbnail.save(output, format="JPEG", quality=85, optimize=True)
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return output.getvalue()
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except Exception as e:
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logger.error(f"生成缩略图失败: {str(e)}")
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# 如果缩略图生成失败，返回一个1x1的透明图片
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with io.BytesIO() as output:
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empty_img = Image.new("RGB", (1, 1), color="white")
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empty_img.save(output, format="JPEG", quality=85)
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return output.getvalue()
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def _compress_image(self, img: Image.Image, original_format: str) -> tuple[bytes, str]:
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"""
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压缩图片，如果超过大小限制
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Args:
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img: PIL Image对象
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original_format: 原始格式
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Returns:
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Tuple[bytes, str]: (压缩后的图片数据, 最终格式)
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"""
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# 创建副本
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processed_img = img.copy()
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# 转换为RGB模式（如果需要）
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if processed_img.mode in ("RGBA", "LA", "P"):
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processed_img = processed_img.convert("RGB")
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# 尝试保持原始格式，但优先使用JPEG（更好的压缩）
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target_format = "JPEG" if original_format != "PNG" else "PNG"
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# 初始质量设置
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quality = 85
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with io.BytesIO() as output:
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# 第一次保存以检查大小
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processed_img.save(output, format=target_format, quality=quality, optimize=True)
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compressed_data = output.getvalue()
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# 如果文件大小合适，直接返回
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if len(compressed_data) <= self.MAX_FILE_SIZE:
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return compressed_data, target_format
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# 如果文件太大，逐步降低质量
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while len(compressed_data) > self.MAX_FILE_SIZE and quality > 10:
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quality -= 10
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output.seek(0)
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output.truncate(0)
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processed_img.save(output, format=target_format, quality=quality, optimize=True)
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compressed_data = output.getvalue()
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# 如果质量降到最低仍然太大，尝试缩小尺寸
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if len(compressed_data) > self.MAX_FILE_SIZE:
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# 逐步缩小尺寸
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scale_factor = 0.9
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while len(compressed_data) > self.MAX_FILE_SIZE and scale_factor > 0.3:
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new_width = int(processed_img.width * scale_factor)
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new_height = int(processed_img.height * scale_factor)
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resized_img = processed_img.resize((new_width, new_height), Image.Resampling.LANCZOS)
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output.seek(0)
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output.truncate(0)
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resized_img.save(output, format=target_format, quality=85, optimize=True)
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compressed_data = output.getvalue()
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scale_factor -= 0.1
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return compressed_data, target_format
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# 全局实例
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image_processor = ImageProcessor()
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def process_uploaded_image(image_data: bytes, filename: str = "") -> dict:
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"""
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处理上传的图片（便捷函数）
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Args:
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image_data: 图片二进制数据
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filename: 文件名
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Returns:
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dict: 处理结果
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"""
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return image_processor.process_image(image_data, filename)
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