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TERES_fastapi_backend/ocr/service.py

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#
# Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""
OCR 服务统一接口
支持本地OCR模型和HTTP接口两种方式可通过配置选择
"""
import logging
import os
from abc import ABC, abstractmethod
from typing import Optional, Callable, List, Tuple, Any
logger = logging.getLogger(__name__)
class OCRService(ABC):
"""OCR服务抽象接口"""
@abstractmethod
async def remove_tag(self, text: str) -> str:
"""
移除文本中的位置标签
Args:
text: 包含位置标签的文本
Returns:
清理后的文本
"""
pass
@abstractmethod
def remove_tag_sync(self, text: str) -> str:
"""
同步版本的 remove_tag用于同步代码
Args:
text: 包含位置标签的文本
Returns:
清理后的文本
"""
pass
@abstractmethod
async def extract_positions(self, text: str) -> List[Tuple[List[int], float, float, float, float]]:
"""
从文本中提取位置信息
Args:
text: 包含位置标签的文本
Returns:
位置信息列表格式为 [(页码列表, left, right, top, bottom), ...]
"""
pass
@abstractmethod
def extract_positions_sync(self, text: str) -> List[Tuple[List[int], float, float, float, float]]:
"""
同步版本的 extract_positions用于同步代码
Args:
text: 包含位置标签的文本
Returns:
位置信息列表
"""
pass
@abstractmethod
async def parse_into_bboxes(
self,
pdf_bytes: bytes,
callback: Optional[Callable[[float, str], None]] = None,
zoomin: int = 3,
filename: str = "document.pdf"
) -> List[dict]:
"""
解析 PDF 并返回边界框
Args:
pdf_bytes: PDF 文件的二进制数据
callback: 进度回调函数 (progress: float, message: str) -> None
zoomin: 图像放大倍数1-5默认为3
filename: 文件名仅用于日志
Returns:
边界框列表
"""
pass
@abstractmethod
def parse_into_bboxes_sync(
self,
pdf_bytes: bytes,
callback: Optional[Callable[[float, str], None]] = None,
zoomin: int = 3,
filename: str = "document.pdf"
) -> List[dict]:
"""
同步版本的 parse_into_bboxes用于同步代码
Args:
pdf_bytes: PDF 文件的二进制数据
callback: 进度回调函数注意HTTP 调用中无法实时传递回调此参数将被忽略
zoomin: 图像放大倍数1-5默认为3
filename: 文件名仅用于日志
Returns:
边界框列表
"""
pass
class LocalOCRService(OCRService):
"""本地OCR服务实现直接调用本地OCR模型"""
def __init__(self, parser_instance=None):
"""
初始化本地OCR服务
Args:
parser_instance: SimplePdfParser 实例如果不提供则自动创建
"""
if parser_instance is None:
from ocr import SimplePdfParser
from ocr.config import MODEL_DIR
logger.info(f"Initializing local OCR parser with model_dir={MODEL_DIR}")
self.parser = SimplePdfParser(model_dir=MODEL_DIR)
else:
self.parser = parser_instance
async def remove_tag(self, text: str) -> str:
"""使用本地解析器的静态方法移除标签"""
# SimplePdfParser.remove_tag 是静态方法,可以直接调用
return self.parser.remove_tag(text)
def remove_tag_sync(self, text: str) -> str:
"""同步版本的 remove_tag"""
return self.parser.remove_tag(text)
async def extract_positions(self, text: str) -> List[Tuple[List[int], float, float, float, float]]:
"""使用本地解析器的静态方法提取位置"""
# SimplePdfParser.extract_positions 是静态方法,可以直接调用
return self.parser.extract_positions(text)
def extract_positions_sync(self, text: str) -> List[Tuple[List[int], float, float, float, float]]:
"""同步版本的 extract_positions"""
return self.parser.extract_positions(text)
async def parse_into_bboxes(
self,
pdf_bytes: bytes,
callback: Optional[Callable[[float, str], None]] = None,
zoomin: int = 3,
filename: str = "document.pdf"
) -> List[dict]:
"""使用本地解析器解析PDF"""
# 本地解析器可以直接接受BytesIO
import asyncio
from io import BytesIO
# 在后台线程中运行同步方法
loop = asyncio.get_event_loop()
bboxes = await loop.run_in_executor(
None,
lambda: self.parser.parse_into_bboxes(BytesIO(pdf_bytes), callback=callback, zoomin=zoomin)
)
return bboxes
def parse_into_bboxes_sync(
self,
pdf_bytes: bytes,
callback: Optional[Callable[[float, str], None]] = None,
zoomin: int = 3,
filename: str = "document.pdf"
) -> List[dict]:
"""同步版本的 parse_into_bboxes"""
from io import BytesIO
# 本地解析器可以直接接受BytesIO
return self.parser.parse_into_bboxes(BytesIO(pdf_bytes), callback=callback, zoomin=zoomin)
class HTTPOCRService(OCRService):
"""HTTP OCR服务实现通过HTTP接口调用OCR服务"""
def __init__(self, base_url: Optional[str] = None, timeout: float = 300.0):
"""
初始化HTTP OCR服务
Args:
base_url: OCR 服务的基础 URL如果不提供则从环境变量 OCR_SERVICE_URL 获取
timeout: 请求超时时间默认 300
"""
from ocr.client import OCRClient
self.client = OCRClient(base_url=base_url, timeout=timeout)
async def remove_tag(self, text: str) -> str:
"""通过HTTP接口移除标签"""
return await self.client.remove_tag(text)
def remove_tag_sync(self, text: str) -> str:
"""同步版本的 remove_tag"""
return self.client.remove_tag_sync(text)
async def extract_positions(self, text: str) -> List[Tuple[List[int], float, float, float, float]]:
"""通过HTTP接口提取位置"""
return await self.client.extract_positions(text)
def extract_positions_sync(self, text: str) -> List[Tuple[List[int], float, float, float, float]]:
"""同步版本的 extract_positions"""
return self.client.extract_positions_sync(text)
async def parse_into_bboxes(
self,
pdf_bytes: bytes,
callback: Optional[Callable[[float, str], None]] = None,
zoomin: int = 3,
filename: str = "document.pdf"
) -> List[dict]:
"""通过HTTP接口解析PDF"""
return await self.client.parse_into_bboxes(pdf_bytes, callback, zoomin, filename)
def parse_into_bboxes_sync(
self,
pdf_bytes: bytes,
callback: Optional[Callable[[float, str], None]] = None,
zoomin: int = 3,
filename: str = "document.pdf"
) -> List[dict]:
"""同步版本的 parse_into_bboxes"""
return self.client.parse_into_bboxes_sync(pdf_bytes, callback, zoomin, filename)
# 全局服务实例(懒加载)
_global_service: Optional[OCRService] = None
def get_ocr_service() -> OCRService:
"""
获取全局 OCR 服务实例单例模式
根据环境变量 OCR_MODE 选择使用本地或HTTP方式
- OCR_MODE=local 或未设置使用本地OCR模型
- OCR_MODE=http使用HTTP接口
也可以通过环境变量 OCR_SERVICE_URL 配置HTTP服务的地址仅在OCR_MODE=http时生效
Returns:
OCRService 实例
"""
global _global_service
if _global_service is None:
ocr_mode = os.getenv("OCR_MODE", "local").lower()
if ocr_mode == "http":
base_url = os.getenv("OCR_SERVICE_URL", "http://localhost:8000/api/v1/ocr")
logger.info(f"Initializing HTTP OCR service with URL: {base_url}")
_global_service = HTTPOCRService(base_url=base_url)
else:
logger.info("Initializing local OCR service")
_global_service = LocalOCRService()
return _global_service
# 为了向后兼容,保留 get_ocr_client 函数(但重定向到 get_ocr_service
def get_ocr_client() -> OCRService:
"""
获取OCR服务实例向后兼容函数
建议使用 get_ocr_service() 替代
Returns:
OCRService 实例
"""
return get_ocr_service()