feat: 新增 OCR 单据字段精确提取模块

- 新增 backend/ocr_extractor.py: 两阶段提取流水线 (文档分析 + 字段提取)
- 四种提取策略: 精确KV匹配/模糊KV匹配/正则模式/表格结构匹配
- agent/state.py: 新增 ocr_extraction_result 和 uploaded_file_path 字段
- agent/nodes.py: process_input() 中自动触发 OCR 提取钩子
- app.py: 文件上传时保留图片路径, 总结卡片中展示提取结果
- .env.example: 新增 OCR_USE_GPU / OCR_CONFIDENCE_THRESHOLD 配置项
- tests/test_ocr_extraction.py: 48 个单元测试全部通过
This commit is contained in:
2026-05-20 08:06:55 +08:00
parent 067880bf2e
commit c9f003e1b7
6 changed files with 1417 additions and 2 deletions
+6
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@@ -63,3 +63,9 @@ HISTORY_MAX_SNAPSHOTS=10
# 意图识别模型(默认使用主 LLM 模型)
# INTENT_MODEL=gpt-4o-mini
# OCR 字段提取配置
# 是否使用 GPU 加速 OCR(需要 CUDA 驱动和 GPU 版 EasyOCR/PaddleOCR
OCR_USE_GPU=false
# OCR 文本置信度最低阈值(0-1),低于此值的元素将被忽略
OCR_CONFIDENCE_THRESHOLD=0.5
+25
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@@ -7,6 +7,7 @@ import os
import re
import time
from datetime import datetime, timezone
from pathlib import Path
from typing import Dict
from dotenv import load_dotenv
@@ -114,6 +115,30 @@ def process_input(state: AgentState) -> Dict:
conv_history.append({"role": "user", "content": user_input})
state["conversation_history"] = conv_history
# OCR 单据字段精确提取(处理上传的图片文件)
uploaded_path = state.get("uploaded_file_path", "")
if uploaded_path and Path(uploaded_path).is_file():
suffix = Path(uploaded_path).suffix.lower()
if suffix in (".png", ".jpg", ".jpeg", ".bmp", ".webp"):
try:
from backend.ocr_extractor import OcrExtractor
extractor = OcrExtractor()
ocr_result = extractor.extract(uploaded_path, [])
if ocr_result.get("ocr_available"):
state["ocr_extraction_result"] = ocr_result
_node_log.info(
"OCR 字段提取完成",
extra={
"file": uploaded_path,
"elements": ocr_result.get("total_elements", 0),
"fields": len(ocr_result.get("fields", [])),
},
)
except Exception as e:
_node_log.warning(f"OCR 字段提取失败: {e}")
state["ocr_extraction_result"] = {"error": str(e)}
state["uploaded_file_path"] = ""
# 重置本轮请求字段
state["retry_count"] = 0
state["user_modification_request"] = user_input
+4
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@@ -40,3 +40,7 @@ class AgentState(TypedDict, total=False):
# 需求6:失败上下文传递 — 重试耗尽后暂存失败信息,下次用户输入时自动注入
pending_failure_context: dict
# 需求7:OCR 单据字段精确提取结果
ocr_extraction_result: dict
uploaded_file_path: str
+43 -2
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@@ -261,6 +261,14 @@ def run_agent(user_input: str):
if stream_active:
streaming_placeholder.empty()
# 清理已处理的临时文件
for p in st.session_state.get("uploaded_temp_paths", []):
try:
Path(p).unlink(missing_ok=True)
except Exception:
pass
st.session_state.uploaded_temp_paths = []
# ---- 总结卡片 ----
# 注:node_state 只含变更字段,用 agent_state(被所有节点就地修改)获取完整状态
final_state = agent_state
@@ -324,6 +332,30 @@ def run_agent(user_input: str):
"content": f"❌ 经过 {retries} 次重试后仍无法生成有效的 JRXML。\n\n**错误:** {error_msg}\n\n💡 请直接描述修改需求,系统会自动加载失败上下文。",
"type": "error_explanation",
})
# OCR 字段提取结果展示
ocr_result = agent_state.get("ocr_extraction_result", {})
if ocr_result and ocr_result.get("ocr_available") and ocr_result.get("fields"):
with st.expander("🔍 OCR 单据字段提取结果", expanded=False):
fields = ocr_result.get("fields", [])
non_empty = [f for f in fields if f.get("field_value")]
empty = [f for f in fields if not f.get("field_value")]
if non_empty:
st.markdown("**已提取字段:**")
for f in non_empty:
method = f.get("extraction_method", "")
conf = f.get("confidence", 0)
st.markdown(
f"- **{f['field_name']}**: `{f['field_value']}` "
f"(置信度: {conf:.0%}, 方法: {method}"
)
if empty:
st.caption(
f"未提取到值的字段: {', '.join(f['field_name'] for f in empty)}"
)
st.caption(
f"共检测到 {ocr_result.get('total_elements', 0)} 个文本元素"
)
else:
st.error("未产生结果,请重试。")
@@ -443,6 +475,9 @@ with st.sidebar:
if "uploaded_files" not in st.session_state:
st.session_state.uploaded_files = [] # [{name, text, type}]
if "uploaded_temp_paths" not in st.session_state:
st.session_state.uploaded_temp_paths = [] # 待清理的临时文件路径
uploaded = st.file_uploader(
"选择文件",
type=["png", "jpg", "jpeg", "bmp", "webp", "pdf", "docx", "txt", "csv", "json", "xml"],
@@ -513,8 +548,6 @@ with st.sidebar:
)
parsed_type = "image_reference"
Path(tmp_path).unlink(missing_ok=True)
if parsed_text:
st.session_state.uploaded_files.append({
"name": uf.name,
@@ -522,6 +555,14 @@ with st.sidebar:
"type": parsed_type,
})
# 对图片类型,保存路径以便 OCR 字段提取(延迟到 process_input 阶段)
img_suffixes = (".png", ".jpg", ".jpeg", ".bmp", ".webp")
if suffix in img_suffixes and result.get("method") not in ("metadata_only", None):
st.session_state.agent_state["uploaded_file_path"] = tmp_path
st.session_state.uploaded_temp_paths.append(tmp_path)
else:
Path(tmp_path).unlink(missing_ok=True)
if st.session_state.uploaded_files:
for i, f in enumerate(st.session_state.uploaded_files):
cols = st.columns([5, 1])
+796
View File
@@ -0,0 +1,796 @@
"""OCR 单据字段精确提取器。
两阶段提取流程:
阶段1 - 文档分析: 复用 file_parser.parse_file() 和 layout_analyzer.analyze_layout()
获取每个文本元素的精确坐标和内容
阶段2 - 字段提取: 给定目标字段列表,通过四种策略(精确KV匹配、模糊KV匹配、
正则模式匹配、表格结构匹配)提取字段值、位置和置信度
用法:
from backend.ocr_extractor import OcrExtractor
extractor = OcrExtractor()
result = extractor.extract("invoice.png", ["发票代码", "发票号码", "合计金额"])
for field in result:
print(f"{field['field_name']}: {field['field_value']} (置信度: {field['confidence']})")
"""
import os
import re
from dataclasses import dataclass, field
from pathlib import Path
from typing import Any, Optional
from dotenv import load_dotenv
load_dotenv()
OCR_USE_GPU = os.getenv("OCR_USE_GPU", "false").lower() in ("true", "1", "yes")
OCR_CONFIDENCE_THRESHOLD = float(os.getenv("OCR_CONFIDENCE_THRESHOLD", "0.5"))
@dataclass
class OcrTextElement:
"""OCR 文本元素,包含精确坐标和内容。"""
text: str
x_min: float
y_min: float
x_max: float
y_max: float
confidence: float = 1.0
@property
def center_x(self) -> float:
return (self.x_min + self.x_max) / 2
@property
def center_y(self) -> float:
return (self.y_min + self.y_max) / 2
@property
def width(self) -> float:
return self.x_max - self.x_min
@property
def height(self) -> float:
return self.y_max - self.y_min
@property
def bbox(self) -> list[float]:
return [self.x_min, self.y_min, self.x_max, self.y_max]
@dataclass
class ExtractedField:
"""提取的字段结果。"""
field_name: str
field_value: str
bbox: list[float]
confidence: float
extraction_method: str
@dataclass
class ExtractionResult:
"""单次提取的完整结果。"""
file_path: str
image_size: tuple[int, int]
fields: list[ExtractedField] = field(default_factory=list)
all_elements: list[OcrTextElement] = field(default_factory=list)
errors: list[str] = field(default_factory=list)
ocr_available: bool = False
def to_dict(self) -> dict:
return {
"file_path": self.file_path,
"image_size": self.image_size,
"ocr_available": self.ocr_available,
"fields": [
{
"field_name": f.field_name,
"field_value": f.field_value,
"bbox": f.bbox,
"confidence": f.confidence,
"extraction_method": f.extraction_method,
}
for f in self.fields
],
"total_elements": len(self.all_elements),
"errors": self.errors,
}
class OcrExtractor:
"""OCR 单据字段精确提取器。
两阶段流水线:
阶段1: 对上传图片进行 OCR + 版面分析,产出带坐标的文本元素列表
阶段2: 根据目标字段列表,按优先级逐一尝试四种提取策略
"""
def __init__(
self,
use_gpu: bool = False,
confidence_threshold: float = 0.5,
):
"""初始化提取器。
Args:
use_gpu: 是否使用 GPU 加速 OCR(需要相应驱动)
confidence_threshold: OCR 文本置信度最低阈值,低于此值的元素被忽略
"""
self.use_gpu = use_gpu if use_gpu else OCR_USE_GPU
self.confidence_threshold = (
confidence_threshold
if confidence_threshold != 0.5
else OCR_CONFIDENCE_THRESHOLD
)
# ========================================================================
# 公共接口
# ========================================================================
def extract(
self,
file_path: str,
target_fields: list[str],
) -> dict:
"""执行两阶段 OCR 字段提取。
Args:
file_path: 图片文件路径(支持 png/jpg/jpeg/bmp/webp
target_fields: 需要提取的字段名称列表,如 ["发票代码", "发票号码", "合计金额"]
Returns:
提取结果字典,格式见 ExtractionResult.to_dict()
"""
result = ExtractionResult(file_path=file_path, image_size=(0, 0))
if not Path(file_path).exists():
result.errors.append(f"文件不存在: {file_path}")
return result.to_dict()
elements, image_size = self._analyze_document(file_path)
result.image_size = image_size
result.all_elements = elements
if not elements:
result.ocr_available = self._check_ocr_availability()
if not result.ocr_available:
result.errors.append(
"OCR 引擎不可用,请安装 easyocr (pip install easyocr) 或 paddleocr"
)
else:
result.errors.append("图片未检测到文字元素")
return result.to_dict()
result.ocr_available = True
for field_name in target_fields:
extracted = self._extract_field(field_name, elements)
if extracted:
result.fields.append(extracted)
else:
result.fields.append(
ExtractedField(
field_name=field_name,
field_value="",
bbox=[],
confidence=0.0,
extraction_method="none",
)
)
return result.to_dict()
def extract_from_layout_result(
self,
layout_result: dict,
target_fields: list[str],
) -> dict:
"""直接从 layout_analyzer.analyze_layout() 的结果中提取字段。
当已有版面分析结果时,跳过阶段1的重复 OCR,直接进入阶段2。
Args:
layout_result: analyze_layout() 的返回值
target_fields: 需要提取的字段名称列表
Returns:
提取结果字典
"""
rows = layout_result.get("rows", [])
if not rows:
return ExtractionResult(
file_path="(from layout)",
image_size=layout_result.get("image_size", (0, 0)),
errors=["版面分析结果中没有文本行"],
).to_dict()
elements = []
for row in rows:
for elem_data in row.get("elements", []):
elements.append(
OcrTextElement(
text=elem_data.get("text", ""),
x_min=elem_data.get("x", 0),
y_min=elem_data.get("y", 0),
x_max=elem_data.get("x", 0) + elem_data.get("w", 0),
y_max=elem_data.get("y", 0) + elem_data.get("h", 0),
)
)
result = ExtractionResult(
file_path="(from layout)",
image_size=layout_result.get("image_size", (0, 0)),
all_elements=elements,
ocr_available=True,
)
for field_name in target_fields:
extracted = self._extract_field(field_name, elements)
if extracted:
result.fields.append(extracted)
else:
result.fields.append(
ExtractedField(
field_name=field_name,
field_value="",
bbox=[],
confidence=0.0,
extraction_method="none",
)
)
return result.to_dict()
# ========================================================================
# 阶段1: 文档分析
# ========================================================================
def _analyze_document(self, file_path: str) -> tuple[list[OcrTextElement], tuple[int, int]]:
"""阶段1: OCR + 版面分析,产出带坐标的文本元素列表。"""
from backend.layout_analyzer import _load_image, _ocr_elements
img = _load_image(Path(file_path))
if img is None:
return [], (0, 0)
image_size = img.size
raw_elements = self._ocr_elements_enhanced(img, file_path)
elements = []
for e_data in raw_elements:
if e_data.get("confidence", 1.0) < self.confidence_threshold:
continue
elements.append(
OcrTextElement(
text=e_data.get("text", ""),
x_min=e_data.get("x", 0),
y_min=e_data.get("y", 0),
x_max=e_data.get("x", 0) + e_data.get("w", 0),
y_max=e_data.get("y", 0) + e_data.get("h", 0),
confidence=e_data.get("confidence", 1.0),
)
)
elements.sort(key=lambda e: (e.y_min, e.x_min))
return elements, image_size
def _ocr_elements_enhanced(self, img, file_path: str) -> list[dict]:
"""增强版 OCR,返回带置信度的元素列表。"""
try:
import numpy as np
easyocr_result = self._try_easyocr(np.array(img))
if easyocr_result:
return easyocr_result
paddleocr_result = self._try_paddleocr(img, file_path)
if paddleocr_result:
return paddleocr_result
except Exception:
pass
return []
def _try_easyocr(self, np_img) -> Optional[list[dict]]:
try:
import easyocr
reader = easyocr.Reader(
["ch_sim", "en"],
gpu=self.use_gpu,
verbose=False,
)
raw_result = reader.readtext(np_img)
elements = []
for bbox, text, confidence in raw_result:
if not text.strip():
continue
xs = [p[0] for p in bbox]
ys = [p[1] for p in bbox]
x_min, x_max = min(xs), max(xs)
y_min, y_max = min(ys), max(ys)
elements.append({
"x": round(x_min, 1),
"y": round(y_min, 1),
"w": round(x_max - x_min, 1),
"h": round(y_max - y_min, 1),
"text": text.strip(),
"confidence": round(confidence, 4),
})
elements.sort(key=lambda e: (e["y"], e["x"]))
return elements
except ImportError:
return None
except Exception:
return None
def _try_paddleocr(self, img, file_path: str) -> Optional[list[dict]]:
try:
from paddleocr import PaddleOCR
import numpy as np
ocr = PaddleOCR(lang="ch")
raw_result = ocr.ocr(np.array(img))
elements = []
if raw_result and raw_result[0]:
for line in raw_result[0]:
if len(line) < 2:
continue
box = line[0]
text_info = line[1]
if isinstance(text_info, (list, tuple)):
text = text_info[0]
confidence = text_info[1] if len(text_info) > 1 else 1.0
else:
text = str(text_info)
confidence = 1.0
if not text.strip():
continue
xs = [p[0] for p in box]
ys = [p[1] for p in box]
x_min, x_max = min(xs), max(xs)
y_min, y_max = min(ys), max(ys)
elements.append({
"x": round(x_min, 1),
"y": round(y_min, 1),
"w": round(x_max - x_min, 1),
"h": round(y_max - y_min, 1),
"text": text.strip(),
"confidence": round(float(confidence), 4),
})
elements.sort(key=lambda e: (e["y"], e["x"]))
return elements
except ImportError:
return None
except Exception:
return None
def _check_ocr_availability(self) -> bool:
try:
import easyocr
return True
except ImportError:
pass
try:
import paddleocr
return True
except ImportError:
pass
return False
# ========================================================================
# 阶段2: 字段精确提取
# ========================================================================
def _extract_field(
self,
field_name: str,
elements: list[OcrTextElement],
) -> Optional[ExtractedField]:
"""按优先级尝试四种策略提取单个字段。
策略优先级:
1. 精确键值对匹配
2. 模糊键值对匹配
3. 正则模式匹配
4. 表格结构匹配
"""
strategies = [
("exact_match", self._exact_kv_match),
("kv_pair", self._fuzzy_kv_match),
("regex", self._regex_match),
("table_match", self._table_match),
]
for method_name, strategy_fn in strategies:
result = strategy_fn(field_name, elements)
if result and result.field_value:
result.extraction_method = method_name
return result
return None
# -----------------------------------------------------------------------
# 策略1: 精确键值对匹配
# -----------------------------------------------------------------------
def _exact_kv_match(
self,
field_name: str,
elements: list[OcrTextElement],
) -> Optional[ExtractedField]:
"""精确键值对匹配: 识别"字段名: 值""字段名:值"模式。
在同一文本元素中查找 "字段名" 后紧跟分隔符 + "" 的模式。
如 OCR 识别出 "发票代码: 12345678" 这一整个元素。
"""
separators = [":", "", "=", "-", "", "", "\t", "|"]
field_name_clean = field_name.strip()
for elem in elements:
text = elem.text
if field_name_clean not in text:
continue
for sep in separators:
pattern = re.escape(field_name_clean) + r"\s*" + re.escape(sep) + r"\s*(.+)"
m = re.search(pattern, text)
if m:
value = m.group(1).strip()
if value:
return ExtractedField(
field_name=field_name,
field_value=value,
bbox=elem.bbox,
confidence=0.95,
extraction_method="",
)
simple_pattern = re.escape(field_name_clean) + r"\s+(.+)"
m = re.search(simple_pattern, text)
if m:
value = m.group(1).strip()
if value and value != field_name_clean:
return ExtractedField(
field_name=field_name,
field_value=value,
bbox=elem.bbox,
confidence=0.85,
extraction_method="",
)
return None
# -----------------------------------------------------------------------
# 策略2: 模糊键值对匹配
# -----------------------------------------------------------------------
def _fuzzy_kv_match(
self,
field_name: str,
elements: list[OcrTextElement],
) -> Optional[ExtractedField]:
"""模糊键值对匹配: 字段名和值分布在相邻的文本元素中。
找到含字段名的元素后,在同一行或相邻元素中查找值。
"""
field_name_clean = field_name.strip()
field_elem = None
for elem in elements:
if field_name_clean in elem.text:
field_elem = elem
break
if field_elem is None:
matching = []
for elem in elements:
sim = self._text_similarity(field_name_clean, elem.text)
if sim > 0.6:
matching.append((sim, elem))
if matching:
matching.sort(key=lambda x: x[0], reverse=True)
field_elem = matching[0][1]
if field_elem is None:
return None
candidates = []
for elem in elements:
if elem is field_elem:
continue
candidates.append(elem)
same_row = []
for elem in candidates:
if abs(elem.center_y - field_elem.center_y) < field_elem.height * 1.5:
same_row.append(elem)
if same_row:
same_row.sort(key=lambda e: e.x_min)
for elem in same_row:
if elem.x_min > field_elem.x_max:
return ExtractedField(
field_name=field_name,
field_value=elem.text,
bbox=elem.bbox,
confidence=0.75,
extraction_method="",
)
nearest = None
nearest_dist = float("inf")
for elem in candidates:
if elem.y_min > field_elem.y_max:
dy = elem.y_min - field_elem.y_max
dx = abs(elem.center_x - field_elem.center_x)
dist = dy + dx * 0.3
if dist < nearest_dist and dy < field_elem.height * 3:
nearest_dist = dist
nearest = elem
if nearest:
return ExtractedField(
field_name=field_name,
field_value=nearest.text,
bbox=nearest.bbox,
confidence=0.6,
extraction_method="",
)
return None
# -----------------------------------------------------------------------
# 策略3: 正则模式匹配
# -----------------------------------------------------------------------
PREDEFINED_PATTERNS: dict[str, str] = {
"发票代码": r"[0-9A-Za-z]{10,12}",
"发票号码": r"\d{8}",
"合计金额": r"[\d,]+\.?\d*",
"金额": r"[\d,]+\.?\d*",
"开票日期": r"\d{4}[年/\-]\d{1,2}[月/\-]\d{1,2}日?",
"日期": r"\d{4}[年/\-]\d{1,2}[月/\-]\d{1,2}日?",
"校验码": r"[0-9A-Fa-f]{5,20}",
"总价": r"[\d,]+\.?\d*",
"总金额": r"[\d,]+\.?\d*",
"价税合计": r"[\d,]+\.?\d*",
"数量": r"\d+\.?\d*",
"单价": r"[\d,]+\.?\d*",
"税率": r"\d+\.?\d*%?",
}
def _regex_match(
self,
field_name: str,
elements: list[OcrTextElement],
) -> Optional[ExtractedField]:
"""正则模式匹配: 根据字段名选择预定义的正则模式,在所有元素中搜索。"""
pattern = self.PREDEFINED_PATTERNS.get(field_name)
if not pattern:
for key, pat in self.PREDEFINED_PATTERNS.items():
if key in field_name or field_name in key:
pattern = pat
break
if not pattern:
return None
compiled = re.compile(r"^\s*" + pattern + r"\s*$")
for elem in elements:
if compiled.match(elem.text):
return ExtractedField(
field_name=field_name,
field_value=elem.text.strip(),
bbox=elem.bbox,
confidence=0.7,
extraction_method="",
)
compiled_partial = re.compile(pattern)
for elem in elements:
m = compiled_partial.search(elem.text)
if m:
return ExtractedField(
field_name=field_name,
field_value=m.group(0),
bbox=elem.bbox,
confidence=0.6,
extraction_method="",
)
return None
# -----------------------------------------------------------------------
# 策略4: 表格结构匹配
# -----------------------------------------------------------------------
def _table_match(
self,
field_name: str,
elements: list[OcrTextElement],
) -> Optional[ExtractedField]:
"""表格结构匹配: 将元素按行列分组,查找表头-值对应关系。
识别逻辑:
1. 将元素按 Y 坐标分组为""
2. 查找包含 field_name 的表头行
3. 在表头列对应的数据行中取值
"""
if len(elements) < 3:
return None
rows = self._group_elements_by_rows(elements)
if len(rows) < 2:
return None
header_row_idx = -1
header_col_idx = -1
for ri, row in enumerate(rows):
for ci, elem in enumerate(row):
if field_name in elem.text:
header_row_idx = ri
header_col_idx = ci
break
if header_row_idx >= 0:
break
if header_row_idx < 0:
for ri, row in enumerate(rows):
for ci, elem in enumerate(row):
sim = self._text_similarity(field_name, elem.text)
if sim > 0.5:
header_row_idx = ri
header_col_idx = ci
break
if header_row_idx >= 0:
break
if header_row_idx < 0:
return None
data_rows = rows[header_row_idx + 1:]
if not data_rows:
data_rows = [rows[header_row_idx]]
matched_elem = None
for row in data_rows:
if header_col_idx < len(row):
matched_elem = row[header_col_idx]
break
closest = None
min_dist = float("inf")
header_x = float("inf")
if header_col_idx < len(rows[header_row_idx]):
header_x = rows[header_row_idx][header_col_idx].center_x
for elem in row:
dist = abs(elem.center_x - header_x)
if dist < min_dist:
min_dist = dist
closest = elem
if closest:
matched_elem = closest
break
if matched_elem and matched_elem.text != field_name:
return ExtractedField(
field_name=field_name,
field_value=matched_elem.text,
bbox=matched_elem.bbox,
confidence=0.55,
extraction_method="",
)
return None
# ========================================================================
# 工具方法
# ========================================================================
@staticmethod
def _group_elements_by_rows(
elements: list[OcrTextElement],
) -> list[list[OcrTextElement]]:
"""将元素按 Y 坐标分组为行(容差为元素平均高度的一半)。"""
if not elements:
return []
avg_height = sum(e.height for e in elements) / len(elements)
tolerance = max(avg_height * 0.5, 5.0)
rows = []
current_row = [elements[0]]
for elem in elements[1:]:
prev_center_y = current_row[0].center_y
if abs(elem.center_y - prev_center_y) < tolerance:
current_row.append(elem)
else:
current_row.sort(key=lambda e: e.x_min)
rows.append(current_row)
current_row = [elem]
if current_row:
current_row.sort(key=lambda e: e.x_min)
rows.append(current_row)
return rows
@staticmethod
def _text_similarity(text1: str, text2: str) -> float:
"""计算两个文本的简单相似度(公共字符比例)。"""
if not text1 or not text2:
return 0.0
t1 = text1.lower().strip()
t2 = text2.lower().strip()
if t1 == t2:
return 1.0
if t1 in t2 or t2 in t1:
return 0.8
chars1 = set(t1)
chars2 = set(t2)
if not chars1:
return 0.0
intersection = chars1 & chars2
return len(intersection) / len(chars1)
def extract_ocr_fields(
file_path: str,
target_fields: list[str],
use_gpu: bool = False,
confidence_threshold: float = 0.5,
) -> dict:
"""便捷函数: 对指定图片执行 OCR 字段提取。
Args:
file_path: 图片文件路径
target_fields: 目标字段名列表
use_gpu: 是否使用 GPU 加速
confidence_threshold: OCR 置信度阈值
Returns:
提取结果字典
"""
extractor = OcrExtractor(
use_gpu=use_gpu,
confidence_threshold=confidence_threshold,
)
return extractor.extract(file_path, target_fields)
def extract_from_layout(
layout_result: dict,
target_fields: list[str],
confidence_threshold: float = 0.5,
) -> dict:
"""便捷函数: 从已有的版面分析结果中提取字段。
Args:
layout_result: analyze_layout() 的返回值
target_fields: 目标字段名列表
confidence_threshold: OCR 置信度阈值
Returns:
提取结果字典
"""
extractor = OcrExtractor(confidence_threshold=confidence_threshold)
return extractor.extract_from_layout_result(layout_result, target_fields)
+543
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"""OCR 单据字段提取器单元测试。
覆盖:
- OcrTextElement / ExtractedField / ExtractionResult 数据结构
- 四种提取策略的独立测试
- 坐标计算正确性
- 边界情况(空元素、无匹配、部分匹配)
"""
import sys
import os
import math
from pathlib import Path
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
import pytest
from backend.ocr_extractor import (
OcrTextElement,
ExtractedField,
ExtractionResult,
OcrExtractor,
extract_ocr_fields,
extract_from_layout,
)
class TestOcrTextElement:
"""测试 OcrTextElement 数据类。"""
def test_bbox_property(self):
elem = OcrTextElement(
text="发票代码",
x_min=100.0,
y_min=50.0,
x_max=250.0,
y_max=80.0,
)
assert elem.bbox == [100.0, 50.0, 250.0, 80.0]
def test_center_coordinates(self):
elem = OcrTextElement(
text="测试",
x_min=100.0,
y_min=50.0,
x_max=200.0,
y_max=100.0,
)
assert elem.center_x == 150.0
assert elem.center_y == 75.0
def test_width_height(self):
elem = OcrTextElement(
text="测试",
x_min=10.0,
y_min=20.0,
x_max=100.0,
y_max=70.0,
)
assert elem.width == 90.0
assert elem.height == 50.0
def test_default_confidence(self):
elem = OcrTextElement(
text="测试",
x_min=0,
y_min=0,
x_max=10,
y_max=10,
)
assert elem.confidence == 1.0
class TestExtractedField:
"""测试 ExtractedField 数据类。"""
def test_field_creation(self):
field = ExtractedField(
field_name="发票代码",
field_value="1234567890",
bbox=[100, 50, 200, 80],
confidence=0.95,
extraction_method="exact_match",
)
assert field.field_name == "发票代码"
assert field.field_value == "1234567890"
assert field.bbox == [100, 50, 200, 80]
assert field.confidence == 0.95
assert field.extraction_method == "exact_match"
class TestExtractionResult:
"""测试 ExtractionResult 数据类。"""
def test_to_dict_basic(self):
result = ExtractionResult(
file_path="/test/invoice.png",
image_size=(800, 600),
ocr_available=True,
)
d = result.to_dict()
assert d["file_path"] == "/test/invoice.png"
assert d["image_size"] == (800, 600)
assert d["ocr_available"] is True
assert d["fields"] == []
assert d["total_elements"] == 0
assert d["errors"] == []
def test_to_dict_with_fields(self):
result = ExtractionResult(
file_path="/test/invoice.png",
image_size=(800, 600),
ocr_available=True,
)
result.fields.append(
ExtractedField(
field_name="发票代码",
field_value="1234567890",
bbox=[100, 50, 200, 80],
confidence=0.95,
extraction_method="exact_match",
)
)
d = result.to_dict()
assert len(d["fields"]) == 1
assert d["fields"][0]["field_name"] == "发票代码"
assert d["fields"][0]["field_value"] == "1234567890"
assert d["fields"][0]["bbox"] == [100, 50, 200, 80]
assert d["fields"][0]["confidence"] == 0.95
assert d["fields"][0]["extraction_method"] == "exact_match"
def test_to_dict_with_error(self):
result = ExtractionResult(
file_path="/test/missing.png",
image_size=(0, 0),
errors=["文件不存在: /test/missing.png"],
)
d = result.to_dict()
assert d["errors"] == ["文件不存在: /test/missing.png"]
class TestElementGrouping:
"""测试元素行分组功能。"""
def test_group_single_row(self):
elements = [
OcrTextElement("A", 10, 50, 50, 70),
OcrTextElement("B", 60, 50, 110, 70),
OcrTextElement("C", 120, 50, 170, 70),
]
rows = OcrExtractor._group_elements_by_rows(elements)
assert len(rows) == 1
assert len(rows[0]) == 3
def test_group_multiple_rows(self):
elements = [
OcrTextElement("A1", 10, 50, 50, 70),
OcrTextElement("B1", 60, 50, 110, 70),
OcrTextElement("A2", 10, 120, 50, 140),
OcrTextElement("B2", 60, 120, 110, 140),
OcrTextElement("A3", 10, 200, 50, 220),
]
rows = OcrExtractor._group_elements_by_rows(elements)
assert len(rows) == 3
assert len(rows[0]) == 2
assert len(rows[1]) == 2
assert len(rows[2]) == 1
def test_group_empty(self):
rows = OcrExtractor._group_elements_by_rows([])
assert rows == []
def test_group_single_element(self):
rows = OcrExtractor._group_elements_by_rows([
OcrTextElement("X", 10, 50, 50, 70)
])
assert len(rows) == 1
assert len(rows[0]) == 1
class TestTextSimilarity:
"""测试文本相似度计算。"""
def test_exact_match(self):
sim = OcrExtractor._text_similarity("发票代码", "发票代码")
assert sim == 1.0
def test_partial_match(self):
sim = OcrExtractor._text_similarity("发票代码", "代码")
assert sim > 0.5
def test_no_match(self):
sim = OcrExtractor._text_similarity("发票代码", "xyz")
assert sim == 0.0
def test_empty_strings(self):
assert OcrExtractor._text_similarity("", "abc") == 0.0
assert OcrExtractor._text_similarity("abc", "") == 0.0
assert OcrExtractor._text_similarity("", "") == 0.0
def test_substring_match(self):
sim = OcrExtractor._text_similarity("代码", "发票代码")
assert sim > 0.7
class TestExactKVMatch:
"""测试策略1: 精确键值对匹配。"""
def test_colon_separator(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("发票代码: 1234567890", 50, 50, 300, 80),
]
result = extractor._exact_kv_match("发票代码", elements)
assert result is not None
assert result.field_value == "1234567890"
assert result.confidence == 0.95
def test_chinese_colon(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("发票号码:87654321", 50, 50, 300, 80),
]
result = extractor._exact_kv_match("发票号码", elements)
assert result is not None
assert result.field_value == "87654321"
def test_space_separator(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("合计金额 999.00", 50, 50, 300, 80),
]
result = extractor._exact_kv_match("合计金额", elements)
assert result is not None
assert result.field_value == "999.00"
def test_equals_separator(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("数量=5", 50, 50, 200, 80),
]
result = extractor._exact_kv_match("数量", elements)
assert result is not None
assert result.field_value == "5"
def test_field_not_found(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("其他内容: 123", 50, 50, 200, 80),
]
result = extractor._exact_kv_match("发票代码", elements)
assert result is None
class TestFuzzyKVMatch:
"""测试策略2: 模糊键值对匹配。"""
def test_adjacent_same_row(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("发票代码", 50, 50, 150, 80),
OcrTextElement("1234567890", 200, 50, 350, 80),
]
result = extractor._fuzzy_kv_match("发票代码", elements)
assert result is not None
assert result.field_value == "1234567890"
assert result.confidence == 0.75
def test_adjacent_next_row(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("发票代码", 50, 50, 150, 80),
OcrTextElement("1234567890", 50, 100, 200, 130),
]
result = extractor._fuzzy_kv_match("发票代码", elements)
assert result is not None
assert result.field_value == "1234567890"
def test_field_name_not_found(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("其他信息", 50, 50, 150, 80),
OcrTextElement("1234567890", 200, 50, 350, 80),
]
result = extractor._fuzzy_kv_match("发票代码", elements)
assert result is None
class TestRegexMatch:
"""测试策略3: 正则模式匹配。"""
def test_invoice_code_pattern(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("1234567890", 100, 50, 250, 80),
]
result = extractor._regex_match("发票代码", elements)
assert result is not None
assert result.field_value == "1234567890"
def test_invoice_number_pattern(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("87654321", 100, 50, 200, 80),
]
result = extractor._regex_match("发票号码", elements)
assert result is not None
assert result.field_value == "87654321"
def test_amount_pattern(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("1,234.56", 100, 50, 200, 80),
]
result = extractor._regex_match("合计金额", elements)
assert result is not None
assert "1,234.56" in result.field_value
def test_date_pattern(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("2024年1月15日", 100, 50, 250, 80),
]
result = extractor._regex_match("开票日期", elements)
assert result is not None
assert "2024" in result.field_value
def test_unknown_field_no_pattern(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("随便什么内容", 100, 50, 250, 80),
]
result = extractor._regex_match("未知字段", elements)
assert result is None
class TestTableMatch:
"""测试策略4: 表格结构匹配。"""
def test_simple_table(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("名称", 50, 50, 150, 80),
OcrTextElement("数量", 200, 50, 300, 80),
OcrTextElement("单价", 350, 50, 450, 80),
OcrTextElement("商品A", 50, 100, 150, 130),
OcrTextElement("2", 200, 100, 250, 130),
OcrTextElement("10.00", 350, 100, 420, 130),
]
result = extractor._table_match("数量", elements)
assert result is not None
assert result.field_value == "2"
def test_table_with_fuzzy_header(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("品名", 50, 50, 120, 80),
OcrTextElement("金额", 200, 50, 300, 80),
OcrTextElement("苹果", 50, 100, 120, 130),
OcrTextElement("5.00", 200, 100, 260, 130),
]
result = extractor._table_match("合计金额", elements)
# 金额列可能匹配到 "金额"
if result:
assert result.field_value == "5.00"
def test_table_header_not_found(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("A", 50, 50, 100, 80),
OcrTextElement("B", 150, 50, 200, 80),
]
result = extractor._table_match("发票代码", elements)
assert result is None
def test_table_too_few_elements(self):
extractor = OcrExtractor()
elements = [
OcrTextElement("名称", 50, 50, 150, 80),
]
result = extractor._table_match("名称", elements)
assert result is None
class TestCoordinateCorrectness:
"""测试坐标计算正确性。"""
def test_bbox_origin_top_left(self):
"""验证坐标系统以左上角为原点。"""
elem = OcrTextElement("A", 0, 0, 50, 20)
assert elem.x_min == 0
assert elem.y_min == 0
assert elem.bbox[0] == 0
assert elem.bbox[1] == 0
def test_bbox_conversion(self):
"""验证从 (x, y, w, h) 到 [x_min, y_min, x_max, y_max] 的转换。"""
x, y, w, h = 100, 200, 300, 50
elem = OcrTextElement("test", x_min=x, y_min=y, x_max=x + w, y_max=y + h)
assert elem.bbox == [x, y, x + w, y + h]
assert elem.x_max - elem.x_min == w
assert elem.y_max - elem.y_min == h
def test_multiple_elements_coordinate_independence(self):
"""验证多个元素的坐标互不干扰。"""
elements = [
OcrTextElement("A", 10, 20, 60, 40),
OcrTextElement("B", 100, 200, 180, 240),
]
assert elements[0].bbox == [10, 20, 60, 40]
assert elements[1].bbox == [100, 200, 180, 240]
assert elements[0].x_min != elements[1].x_min
def test_center_calculation(self):
"""验证中心点计算。"""
elem = OcrTextElement("test", 0, 0, 100, 100)
assert elem.center_x == 50.0
assert elem.center_y == 50.0
class TestExtractionPipeline:
"""测试完整的提取流水线。"""
def test_priority_order_exact_first(self):
"""验证策略优先级: exact_match 优先于其他策略。"""
extractor = OcrExtractor()
elements = [
OcrTextElement("发票代码: 1234567890", 50, 50, 300, 80),
]
result = extractor._extract_field("发票代码", elements)
assert result is not None
assert result.extraction_method == "exact_match"
def test_fallback_to_fuzzy(self):
"""验证精确匹配失败后回退到模糊匹配。"""
extractor = OcrExtractor()
elements = [
OcrTextElement("发票代码", 50, 50, 150, 80),
OcrTextElement("1234567890", 200, 50, 350, 80),
]
result = extractor._extract_field("发票代码", elements)
assert result is not None
assert result.extraction_method == "kv_pair"
def test_all_fields_empty(self):
"""验证所有字段提取失败时返回空结果。"""
extractor = OcrExtractor()
elements = [
OcrTextElement("一些不相关的文本", 50, 50, 300, 80),
OcrTextElement("更多随机内容", 50, 100, 300, 130),
]
result = extractor._extract_field("发票代码", elements)
assert result is None
def test_empty_elements_list(self):
"""验证空元素列表时正常处理。"""
extractor = OcrExtractor()
result = extractor._extract_field("发票代码", [])
assert result is None
def test_extraction_with_confidence(self):
"""验证提取结果的置信度在合理范围内。"""
extractor = OcrExtractor()
elements = [
OcrTextElement("发票代码: 1234567890", 50, 50, 300, 80),
]
result = extractor._extract_field("发票代码", elements)
assert result is not None
assert 0.0 < result.confidence <= 1.0
class TestExtractFromLayout:
"""测试从 layout 结果中提取字段。"""
def test_basic_layout_extraction(self):
layout_result = {
"image_size": (800, 600),
"template_type": "full_a4",
"rows": [
{
"y_center": 50,
"elements": [
{"x": 50, "y": 30, "w": 150, "h": 30, "text": "发票代码:"},
{"x": 250, "y": 30, "w": 200, "h": 30, "text": "1234567890"},
],
},
{
"y_center": 80,
"elements": [
{"x": 50, "y": 60, "w": 150, "h": 30, "text": "合计金额:"},
{"x": 250, "y": 60, "w": 100, "h": 30, "text": "999.00"},
],
},
],
}
result = extract_from_layout(layout_result, ["发票代码"])
assert result["ocr_available"] is True
assert result["image_size"] == (800, 600)
def test_empty_layout(self):
result = extract_from_layout({}, ["发票代码"])
assert result["ocr_available"] is False
assert len(result["errors"]) > 0
class TestOcrExtractorFileNotFound:
"""测试文件不存在的情况。"""
def test_missing_file(self):
extractor = OcrExtractor()
result = extractor.extract("/nonexistent/file.png", ["发票代码"])
assert result["ocr_available"] is False
assert len(result["errors"]) > 0
assert "文件不存在" in result["errors"][0]
class TestConvenienceFunctions:
"""测试便捷函数。"""
def test_extract_ocr_fields_missing_file(self):
result = extract_ocr_fields("/nonexistent/file.png", ["发票代码"])
assert len(result["errors"]) > 0
def test_extract_from_layout_with_partial_rows(self):
layout_result = {
"image_size": (1200, 800),
"template_type": "partial_rows",
"rows": [
{
"y_center": 100,
"elements": [
{"x": 100, "y": 80, "w": 120, "h": 40, "text": "发票代码"},
{"x": 300, "y": 80, "w": 180, "h": 40, "text": "NO123456"},
],
},
],
}
result = extract_from_layout(layout_result, ["发票代码"])
assert result["ocr_available"] is True
assert len(result["fields"]) == 1
assert result["fields"][0]["field_name"] == "发票代码"
assert result["fields"][0]["field_value"] == "NO123456"