This repository has been archived on 2026-02-15. You can view files and clone it. You cannot open issues or pull requests or push a commit.
Files
openclaw-skills/skills/kb-workflow/src/extractors/easyocr_processor.py
T

356 lines
11 KiB
Python
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
OCR 文字识别处理器(EasyOCR 版本)
使用 EasyOCR 实现视频帧文字识别功能,作为 PaddleOCR 的替代方案
主要优势:不依赖 PaddlePaddle,避免 oneDNN 兼容性问题
"""
import re
import numpy as np
from typing import List, Dict, Any, Tuple
import logging
logger = logging.getLogger(__name__)
class EasyOCRProcessor:
"""
EasyOCR 文字识别处理器
使用 EasyOCR 从视频帧中识别文字,支持批量识别和结果过滤
相比 PaddleOCR 的优势:
- 不依赖 PaddlePaddle,避免 oneDNN 兼容性问题
- 安装更简单,依赖更少
- 支持多种语言(70+ 种)
"""
# 相似度阈值:用于判断两个文本是否相似(基于编辑距离)
SIMILARITY_THRESHOLD = 0.85
# 置信度阈值
CONFIDENCE_THRESHOLD = 0.7
# 最小字幕长度(字符数)
MIN_SUBTITLE_LENGTH = 2
def __init__(self, lang: str = 'ch_sim', use_gpu: bool = False, detail: int = 1):
"""
初始化 OCR 处理器
Args:
lang: 语言支持,'ch_sim' 为简体中文,'ch_tra' 为繁体中文
use_gpu: 是否使用 GPU 加速
detail: 识别结果详细程度(0=只返回文本,1=返回文本+坐标+置信度)
"""
self.lang = lang
self.use_gpu = use_gpu
self.detail = detail
# 初始化 EasyOCR 实例
self._ocr = None
self._initialize_ocr()
def _initialize_ocr(self):
"""初始化 EasyOCR 实例"""
try:
from easyocr import Reader
self._ocr = Reader(
[self.lang],
gpu=self.use_gpu,
verbose=False # 不显示详细日志
)
logger.info("EasyOCR 初始化成功")
except Exception as e:
logger.error(f"EasyOCR 初始化失败: {e}")
raise RuntimeError(f"无法初始化 EasyOCR: {e}")
def _initialize_ocr(self):
"""初始化 EasyOCR 实例"""
try:
from easyocr import Reader
self._ocr = Reader(
[self.lang],
gpu=self.use_gpu,
verbose=False # 不显示详细日志
)
logger.info("EasyOCR 初始化成功")
except Exception as e:
logger.error(f"EasyOCR 初始化失败: {e}")
raise RuntimeError(f"无法初始化 EasyOCR: {e}")
def recognize_frames(self, frames: List[Tuple[np.ndarray, float]]) -> List[Dict[str, Any]]:
"""
批量识别帧中的文字
Args:
frames: 帧列表,每个元素为 (图像数组, 时间戳) 元组
- 图像数组:numpy.ndarray,形状为 (H, W, 3) 的 RGB 图像
- 时间戳:float,单位为秒
Returns:
List[Dict[str, Any]]: 识别结果列表,每个结果包含:
- time: float, 时间戳(秒)
- text: str, 识别的文本
- confidence: float, 置信度 (0-1)
"""
if not frames:
logger.warning("输入帧列表为空")
return []
results = []
for image, timestamp in frames:
try:
# 调用 EasyOCR 进行识别
# EasyOCR 返回格式: [[[x1, y1], [x2, y2], [x3, y3], [x4, y4]], (text, confidence, ...)]
# 根据 detail 参数,返回格式不同:
# detail=0: 返回 [text1, text2, ...]
# detail=1: 返回 [[bbox, (text, confidence)], ...]
ocr_result = self._ocr.readtext(image, detail=self.detail)
if ocr_result:
if self.detail == 0:
# 简单模式:只返回文本列表
for i, text in enumerate(ocr_result):
if text:
results.append({
'time': timestamp,
'text': str(text),
'confidence': 1.0 # 简单模式下没有置信度
})
else:
# 详细模式:返回边界框+文本+置信度
for item in ocr_result:
if len(item) >= 2:
bbox = item[0]
text_info = item[1]
if len(text_info) >= 2:
text, confidence = text_info[0], text_info[1]
# 跳过空文本
if not text:
continue
# 处理置信度:可能是数字或特殊字符
try:
if isinstance(confidence, str):
# 如果是 '?' 或其他特殊字符,使用默认置信度
conf_float = 0.5
else:
conf_float = float(confidence)
except (ValueError, TypeError):
conf_float = 0.5
results.append({
'time': timestamp,
'text': text,
'confidence': conf_float
})
except Exception as e:
logger.warning(f"帧识别失败 (时间戳 {timestamp}s): {e}")
continue
logger.info(f"原始识别结果数量: {len(results)}")
# 过滤和清洗结果
filtered_results = self._filter_and_clean(results)
logger.info(f"过滤后结果数量: {len(filtered_results)}")
return filtered_results
def _filter_and_clean(self, results: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
"""
过滤和清洗识别结果
Args:
results: 原始识别结果列表
Returns:
List[Dict[str, Any]]: 过滤后的结果列表
"""
if not results:
return []
# 步骤 1: 按置信度过滤
filtered = self._filter_by_confidence(results)
logger.debug(f"置信度过滤后: {len(filtered)}")
# 步骤 2: 过滤噪声(纯符号、单字符等)
filtered = self._filter_noise(filtered)
logger.debug(f"噪声过滤后: {len(filtered)}")
# 步骤 3: 去除重复或相似的文本
filtered = self._remove_duplicates(filtered)
logger.debug(f"去重后: {len(filtered)}")
# 步骤 4: 按时间戳排序
filtered.sort(key=lambda x: x['time'])
return filtered
def _filter_by_confidence(self, results: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
"""
按置信度过滤结果
Args:
results: 识别结果列表
Returns:
List[Dict[str, Any]]: 高置信度结果
"""
return [r for r in results if r['confidence'] >= self.CONFIDENCE_THRESHOLD]
def _filter_noise(self, results: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
"""
过滤噪声结果
过滤条件:
- 文本长度小于最小长度
- 纯符号或空白字符
Args:
results: 识别结果列表
Returns:
List[Dict[str, Any]]: 过滤后的结果
"""
filtered = []
for result in results:
text = result['text'].strip()
# 过滤过短的文本
if len(text) < self.MIN_SUBTITLE_LENGTH:
continue
# 过滤纯符号或空白字符
if self._is_noise(text):
continue
filtered.append(result)
return filtered
def _is_noise(self, text: str) -> bool:
"""
判断文本是否为噪声
Args:
text: 要判断的文本
Returns:
bool: 如果是噪声返回 True
"""
# 使用正则判断是否只包含符号和空白
try:
# 移除标点符号后检查是否为空
# 先替换常见的中文标点
cleaned = re.sub(r'[^\w\u4e00-\u9fff]', '', text)
return len(cleaned) == 0
except:
# 如果正则出错,保守处理,不算噪声
return False
def _remove_duplicates(self, results: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
"""
去除重复或相似的文本
基于编辑距离(Levenshtein distance)判断文本相似度
Args:
results: 识别结果列表(假设已按时间戳排序)
Returns:
List[Dict[str, Any]]: 去重后的结果
"""
if not results:
return []
deduped = [results[0]]
for current in results[1:]:
last = deduped[-1]
# 计算相似度
similarity = self._calculate_similarity(current['text'], last['text'])
# 如果相似度低于阈值,则保留
if similarity < self.SIMILARITY_THRESHOLD:
deduped.append(current)
else:
# 相似文本:保留置信度更高的那个
if current['confidence'] > last['confidence']:
deduped[-1] = current
return deduped
def _calculate_similarity(self, text1: str, text2: str) -> float:
"""
计算两个文本的相似度(基于归一化编辑距离)
Args:
text1: 文本1
text2: 文本2
Returns:
float: 相似度 (0-1),1 表示完全相同
"""
if text1 == text2:
return 1.0
len1, len2 = len(text1), len(text2)
if len1 == 0 or len2 == 0:
return 0.0
# 动态规划计算编辑距离
dp = np.zeros((len1 + 1, len2 + 1))
for i in range(len1 + 1):
dp[i, 0] = i
for j in range(len2 + 1):
dp[0, j] = j
for i in range(1, len1 + 1):
for j in range(1, len2 + 1):
if text1[i-1] == text2[j-1]:
dp[i, j] = dp[i-1, j-1]
else:
dp[i, j] = min(
dp[i-1, j] + 1, # 删除
dp[i, j-1] + 1, # 插入
dp[i-1, j-1] + 1 # 替换
)
edit_distance = dp[len1, len2]
max_len = max(len1, len2)
# 归一化相似度:1 - (编辑距离 / 最大长度)
similarity = 1.0 - (edit_distance / max_len)
return similarity
def get_ocr_info(self) -> Dict[str, Any]:
"""
获取 OCR 处理器信息
Returns:
Dict[str, Any]: OCR 配置信息
"""
return {
'engine': 'easyocr',
'lang': self.lang,
'use_gpu': self.use_gpu,
'detail': self.detail,
'confidence_threshold': self.CONFIDENCE_THRESHOLD,
'similarity_threshold': self.SIMILARITY_THRESHOLD,
'min_subtitle_length': self.MIN_SUBTITLE_LENGTH
}