Files
Enterprise-Knowledge-Base/docreader/parser/ocr_engine.py
T
begoniezhao 2d66abedf0 feat: 新增文档模型类,调整配置与解析逻辑,优化日志及导入
移除日志设置与冗余代码,优化导入、类型提示及OCR后端管理
统一调整各文件模块导入路径为绝对导入
调整导入路径,移除部分导入,优化日志及注释
升级文档解析器为 Docx2Parser,优化超时与图片处理逻辑
2025-11-18 22:37:01 +08:00

328 lines
11 KiB
Python

import io
import logging
import os
import platform
import subprocess
from abc import ABC, abstractmethod
from typing import Dict, Union
import numpy as np
from openai import OpenAI
from PIL import Image
from docreader.utils import endecode
logger = logging.getLogger(__name__)
class OCRBackend(ABC):
"""Base class for OCR backends"""
@abstractmethod
def predict(self, image: Union[str, bytes, Image.Image]) -> str:
"""Extract text from an image
Args:
image: Image file path, bytes, or PIL Image object
Returns:
Extracted text
"""
pass
class DummyOCRBackend(OCRBackend):
"""Dummy OCR backend implementation"""
def predict(self, image: Union[str, bytes, Image.Image]) -> str:
logger.warning("Dummy OCR backend is used")
return ""
class PaddleOCRBackend(OCRBackend):
"""PaddleOCR backend implementation"""
def __init__(self):
"""Initialize PaddleOCR backend"""
self.ocr = None
try:
import paddle
# Set PaddlePaddle to use CPU and disable GPU
os.environ["CUDA_VISIBLE_DEVICES"] = ""
paddle.device.set_device("cpu")
# 尝试检测CPU是否支持AVX指令集
try:
# 检测CPU是否支持AVX
if platform.system() == "Linux":
try:
result = subprocess.run(
["grep", "-o", "avx", "/proc/cpuinfo"],
capture_output=True,
text=True,
timeout=5,
)
has_avx = "avx" in result.stdout.lower()
if not has_avx:
logger.warning(
"CPU does not support AVX instructions, "
"using compatibility mode"
)
# 进一步限制指令集使用
os.environ["FLAGS_use_avx2"] = "0"
os.environ["FLAGS_use_avx"] = "1"
except (
subprocess.TimeoutExpired,
FileNotFoundError,
subprocess.SubprocessError,
):
logger.warning(
"Could not detect AVX support, using compatibility mode"
)
os.environ["FLAGS_use_avx2"] = "0"
os.environ["FLAGS_use_avx"] = "1"
except Exception as e:
logger.warning(
f"Error detecting CPU capabilities: {e}, using compatibility mode"
)
os.environ["FLAGS_use_avx2"] = "0"
os.environ["FLAGS_use_avx"] = "1"
from paddleocr import PaddleOCR
# OCR configuration with text orientation classification enabled
ocr_config = {
"use_gpu": False,
"text_det_limit_type": "max",
"text_det_limit_side_len": 960,
"use_doc_orientation_classify": True, # 启用文档方向分类
"use_doc_unwarping": False,
"use_textline_orientation": True, # 启用文本行方向检测
"text_recognition_model_name": "PP-OCRv4_server_rec",
"text_detection_model_name": "PP-OCRv4_server_det",
"text_det_thresh": 0.3,
"text_det_box_thresh": 0.6,
"text_det_unclip_ratio": 1.5,
"text_rec_score_thresh": 0.0,
"ocr_version": "PP-OCRv4",
"lang": "ch",
"show_log": False,
"use_dilation": True, # improves accuracy
"det_db_score_mode": "slow", # improves accuracy
}
self.ocr = PaddleOCR(**ocr_config)
logger.info("PaddleOCR engine initialized successfully")
except ImportError as e:
logger.error(
f"Failed to import paddleocr: {str(e)}. "
"Please install it with 'pip install paddleocr'"
)
except OSError as e:
if "Illegal instruction" in str(e) or "core dumped" in str(e):
logger.error(
f"PaddlePaddle crashed due to CPU instruction set incompatibility:"
f"{e}"
)
logger.error(
"This happens when the CPU doesn't support AVX instructions. "
"Try install CPU-only version of PaddlePaddle, "
"or use a different OCR backend."
)
else:
logger.error(
f"Failed to initialize PaddleOCR due to OS error: {str(e)}"
)
except Exception as e:
logger.error(f"Failed to initialize PaddleOCR: {str(e)}")
def predict(self, image: Union[str, bytes, Image.Image]) -> str:
"""Extract text from an image
Args:
image: Image file path, bytes, or PIL Image object
Returns:
Extracted text
"""
if isinstance(image, str):
image = Image.open(image)
elif isinstance(image, bytes):
image = Image.open(io.BytesIO(image))
if not isinstance(image, Image.Image):
raise TypeError("image must be a string, bytes, or PIL Image object")
return self._predict(image)
def _predict(self, image: Image.Image) -> str:
"""Perform OCR recognition on the image
Args:
image: Image object (PIL.Image or numpy array)
Returns:
Extracted text string
"""
if self.ocr is None:
logger.error("PaddleOCR engine not initialized")
return ""
try:
# Ensure image is in RGB format
if image.mode != "RGB":
image = image.convert("RGB")
# Convert to numpy array if needed
image_array = np.array(image)
# Perform OCR
ocr_result = self.ocr.ocr(image_array, cls=False)
# Extract text
ocr_text = ""
if ocr_result and ocr_result[0]:
text = [
line[1][0] if line and len(line) >= 2 and line[1] else ""
for line in ocr_result[0]
]
text = [t.strip() for t in text if t]
ocr_text = " ".join(text)
logger.info(f"OCR extracted {len(ocr_text)} characters")
return ocr_text
except Exception as e:
logger.error(f"OCR recognition error: {str(e)}")
return ""
class NanonetsOCRBackend(OCRBackend):
"""Nanonets OCR backend implementation using OpenAI API format"""
def __init__(self):
"""Initialize Nanonets OCR backend
Args:
api_key: API key for OpenAI API
base_url: Base URL for OpenAI API
model: Model name
"""
base_url = os.getenv("OCR_API_BASE_URL", "http://localhost:8000/v1")
api_key = os.getenv("OCR_API_KEY", "123")
timeout = 30
self.client = OpenAI(api_key=api_key, base_url=base_url, timeout=timeout)
self.model = os.getenv("OCR_MODEL", "nanonets/Nanonets-OCR-s")
logger.info(f"Nanonets OCR engine initialized with model: {self.model}")
self.temperature = 0.0
self.max_tokens = 15000
self.prompt = """## 任务说明
请从上传的文档中提取文字内容,严格按自然阅读顺序(从上到下,从左到右)输出,并遵循以下格式规范。
### 1. **文本处理**
* 按正常阅读顺序提取文字,语句流畅自然。
### 2. **表格**
* 所有表格统一转换为 **Markdown 表格格式**。
* 内容保持清晰、对齐整齐,便于阅读。
### 3. **公式**
* 所有公式转换为 **LaTeX 格式**,使用 `$$公式$$` 包裹。
### 4. **图片**
* 忽略图片信息
### 5. **链接**
* 不要猜测或补全不确定的链接地址。
"""
def predict(self, image: Union[str, bytes, Image.Image]) -> str:
"""Extract text from an image using Nanonets OCR
Args:
image: Image file path, bytes, or PIL Image object
Returns:
Extracted text
"""
if self.client is None:
logger.error("Nanonets OCR client not initialized")
return ""
try:
# Encode image to base64
img_base64 = endecode.decode_image(image)
if not img_base64:
return ""
# Call Nanonets OCR API
logger.info(f"Calling Nanonets OCR API with model: {self.model}")
response = self.client.chat.completions.create(
model=self.model,
messages=[
{
"role": "user",
"content": [
{
"type": "image_url",
"image_url": {
"url": f"data:image/png;base64,{img_base64}"
},
},
{
"type": "text",
"text": self.prompt,
},
],
}
],
temperature=self.temperature,
max_tokens=self.max_tokens,
)
return response.choices[0].message.content or ""
except Exception as e:
logger.error(f"Nanonets OCR prediction error: {str(e)}")
return ""
class OCREngine:
"""OCR Engine factory class"""
_instance: Dict[str, OCRBackend] = {}
@classmethod
def get_instance(cls, backend_type: str) -> OCRBackend:
"""Get OCR engine instance
Args:
backend_type: OCR backend type, one of: "paddle", "nanonets"
**kwargs: Additional arguments for the backend
Returns:
OCR engine instance or None if initialization fails
"""
backend_type = backend_type.lower()
if cls._instance.get(backend_type):
return cls._instance[backend_type]
logger.info(f"Initializing OCR engine with backend: {backend_type}")
if backend_type == "paddle":
cls._instance[backend_type] = PaddleOCRBackend()
elif backend_type == "nanonets":
cls._instance[backend_type] = NanonetsOCRBackend()
else:
cls._instance[backend_type] = DummyOCRBackend()
return cls._instance[backend_type]