feat: 添加汉字书法识别功能及相关依赖

- 新增模型加载、图像预处理和质量评估功能
- 实现基于FastAPI的识别接口和调试接口
- 添加必要的依赖库包括torch和opencv
- 提供健康检查接口和静态文件服务

app.py

@@ -1,7 +1,303 @@
-from fastapi import FastAPI
+import os
+import json
+import torch
+import torch.nn as nn
+from torchvision.models import resnet50
+from torchvision.transforms import transforms
+from PIL import Image, ImageOps, ImageEnhance
+from typing import List, Dict
+from fastapi import FastAPI, File, UploadFile, HTTPException, Request
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.responses import JSONResponse
+import io
+import cv2
+import numpy as np
+import hashlib
+import logging
+from PIL.ExifTags import TAGS
+
+# 设置日志
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+# --- 配置部分 ---
+MODEL_PATH = "best_model.pth"
+MAP_PATH = "char_map.json"
+
+
+# --- 全局初始化模型（启动时加载一次） ---
+class Recognizer:
+    def __init__(self, model_path: str = MODEL_PATH, map_path: str = MAP_PATH):
+        if not os.path.exists(model_path) or not os.path.exists(map_path):
+            raise FileNotFoundError(
+                f"模型文件 '{model_path}' 或字符映射表 '{map_path}' 不存在，"
+                "请先运行 train_model.py 进行模型训练。"
+            )
+
+        self.device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
+
+        # 加载字符映射
+        with open(map_path, "r", encoding="utf-8") as f:
+            self.char_to_idx = json.load(f)
+        self.idx_to_char = {v: k for k, v in self.char_to_idx.items()}
+        num_classes = len(self.char_to_idx)
+
+        # 构建并加载模型
+        self.model = self._get_model(num_classes)
+        try:
+            ckpt = torch.load(model_path, map_location=self.device, weights_only=True)
+        except Exception:
+            ckpt = torch.load(model_path, map_location=self.device, weights_only=False)
+        if isinstance(ckpt, nn.Module):
+            state_dict = ckpt.state_dict()
+        elif isinstance(ckpt, dict):
+            state_dict = ckpt.get("state_dict", ckpt.get("model_state", ckpt))
+        else:
+            raise ValueError("不支持的模型文件格式")
+        self.model.load_state_dict(state_dict, strict=False)
+        self.model.to(self.device)
+        self.model.eval()
+
+        # 定义图像预处理
+        self.transform = transforms.Compose(
+            [
+                transforms.Resize((224, 224)),
+                transforms.ToTensor(),
+                transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225]),
+            ]
+        )
+
+    def _get_model(self, num_classes: int) -> nn.Module:
+        model = resnet50(weights=None)
+        num_ftrs = model.fc.in_features
+        model.fc = nn.Sequential(nn.Dropout(0.3), nn.Linear(num_ftrs, num_classes))
+        return model
+
+    def preprocess_image(self, image_bytes: bytes, user_agent: str = "") -> Image.Image:
+        """统一的图像预处理，特别处理移动设备上传的图片"""
+        try:
+            image = Image.open(io.BytesIO(image_bytes))
+
+            # 记录原始图像信息用于调试
+            logger.info(
+                f"原始图像 - 格式: {image.format}, 模式: {image.mode}, 尺寸: {image.size}"
+            )
+
+            # 处理EXIF方向信息（手机照片常有旋转问题）
+            try:
+                exif = image._getexif()
+                if exif:
+                    for tag, value in exif.items():
+                        decoded = TAGS.get(tag, tag)
+                        if decoded == "Orientation":
+                            if value == 3:
+                                image = image.rotate(180, expand=True)
+                            elif value == 6:
+                                image = image.rotate(270, expand=True)
+                            elif value == 8:
+                                image = image.rotate(90, expand=True)
+                            break
+            except Exception as e:
+                logger.warning(f"EXIF处理失败: {e}")
+
+            # 转换为RGB
+            if image.mode != "RGB":
+                image = image.convert("RGB")
+
+            # 检测是否为移动设备并应用增强处理
+            is_mobile = any(
+                mobile_indicator in user_agent.lower()
+                for mobile_indicator in ["mobile", "iphone", "android", "ipad"]
+            )
+
+            if is_mobile:
+                logger.info("检测到移动设备，应用增强预处理")
+                # 增强对比度
+                enhancer = ImageEnhance.Contrast(image)
+                image = enhancer.enhance(1.2)
+
+                # 轻微锐化
+                enhancer = ImageEnhance.Sharpness(image)
+                image = enhancer.enhance(1.1)
+
+            return image
+
+        except Exception as e:
+            raise ValueError(f"无法处理图片: {e}")
+
+    def assess_image_quality(self, image: Image.Image) -> Dict:
+        """评估图像质量"""
+        # 转换为numpy数组进行处理
+        img_array = np.array(image)
+
+        if len(img_array.shape) == 3:
+            gray = cv2.cvtColor(img_array, cv2.COLOR_RGB2GRAY)
+        else:
+            gray = img_array
+
+        # 计算清晰度（拉普拉斯方差）
+        clarity = cv2.Laplacian(gray, cv2.CV_64F).var()
+
+        # 计算亮度和对比度
+        brightness = np.mean(gray)
+        contrast = np.std(gray)
+
+        quality_info = {
+            "clarity": float(clarity),
+            "brightness": float(brightness),
+            "contrast": float(contrast),
+            "is_acceptable": clarity > 50 and 30 < brightness < 220,
+        }
+
+        logger.info(f"图像质量评估: {quality_info}")
+        return quality_info
+
+    def recognize(
+        self, image_bytes: bytes, top_k: int = 5, user_agent: str = ""
+    ) -> List[Dict[str, str]]:
+        """
+        识别上传的图像。
+
+        Args:
+            image_bytes: 图片的二进制数据。
+            top_k: 返回前k个结果。
+            user_agent: 用户代理字符串，用于设备检测
+
+        Returns:
+            一个字典列表，每个字典包含 `char` 和 `prob` 键。
+        """
+        # 记录图像哈希用于调试
+        image_hash = hashlib.md5(image_bytes).hexdigest()
+        logger.info(f"处理图像 - 哈希: {image_hash}, 设备: {user_agent}")
+
+        # 预处理图像
+        image = self.preprocess_image(image_bytes, user_agent)
+
+        # 评估图像质量
+        quality_info = self.assess_image_quality(image)
+        if not quality_info["is_acceptable"]:
+            logger.warning(f"图像质量可能影响识别: {quality_info}")
+
+        # 应用模型预处理
+        image_tensor = self.transform(image).unsqueeze(0).to(self.device)
+
+        with torch.no_grad():
+            outputs = self.model(image_tensor)
+            probabilities = torch.nn.functional.softmax(outputs, dim=1)
+            top_probs, top_indices = torch.topk(probabilities, top_k)
+
+        results = []
+        top_probs_np = top_probs.cpu().numpy().flatten()
+        top_indices_np = top_indices.cpu().numpy().flatten()
+
+        for i in range(top_k):
+            char_idx = top_indices_np[i]
+            char_name = self.idx_to_char.get(char_idx, "?")
+            probability = top_probs_np[i]
+            results.append({"char": char_name, "prob": f"{probability:.2%}"})
+
+        logger.info(f"识别结果: {results}")
+        return results
+
+
+# --- FastAPI 应用初始化 ---
+app = FastAPI(
+    title="汉字书法字体识别",
+    description="上传一张汉字图片，返回识别出的汉字及其置信度。",
+    version="1.0.0",
+)
+
+# 添加 CORS 中间件
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],  # 生产环境请替换为具体域名
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# 初始化识别器（全局单例）
+try:
+    recognizer = Recognizer()
+    logger.info("模型加载成功，服务已启动")
+except Exception as e:
+    logger.error(f"启动失败: {e}")
+    recognizer = None
+
+
+# --- API 路由 ---
+@app.post("/upload", response_model=List[Dict[str, str]])
+async def upload_image(request: Request, file: UploadFile = File(...)):
+    """
+    上传图片进行汉字识别。
+
+    - **file**: 需要识别的图片文件 (jpg, png, etc.)
+    """
+    if not recognizer:
+        raise HTTPException(status_code=503, detail="服务暂不可用，模型文件未找到。")
+
+    # 检查文件类型
+    if not file.content_type.startswith("image/"):
+        raise HTTPException(status_code=400, detail="上传的文件必须是图片格式。")
+
+    try:
+        image_bytes = await file.read()
+        user_agent = request.headers.get("User-Agent", "")
+        results = recognizer.recognize(image_bytes, top_k=5, user_agent=user_agent)
+        return results
+    except ValueError as ve:
+        logger.error(f"图片处理错误: {ve}")
+        raise HTTPException(status_code=400, detail=str(ve))
+    except Exception as e:
+        logger.error(f"识别错误: {e}")
+        raise HTTPException(status_code=500, detail=f"服务器内部错误: {e}")
+
+
+# 调试接口
+@app.post("/debug_upload")
+async def debug_upload(request: Request, file: UploadFile = File(...)):
+    """调试接口，返回上传图片的详细信息"""
+    try:
+        image_bytes = await file.read()
+        user_agent = request.headers.get("User-Agent", "")
+
+        # 使用recognizer的预处理方法来分析图片
+        image = recognizer.preprocess_image(image_bytes, user_agent)
+        quality_info = recognizer.assess_image_quality(image)
+
+        debug_info = {
+            "file_size": len(image_bytes),
+            "file_hash": hashlib.md5(image_bytes).hexdigest(),
+            "image_size": image.size,
+            "image_mode": image.mode,
+            "quality_assessment": quality_info,
+            "user_agent": user_agent,
+        }
+
+        return JSONResponse(content=debug_info)
+    except Exception as e:
+        logger.error(f"调试接口错误: {e}")
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+from fastapi.staticfiles import StaticFiles
+
+app.mount("/", StaticFiles(directory="static", html=True), name="web")
 
-app = FastAPI()
 
 @app.get("/")
-def greet_json():
-    return {"Hello": "World!"}
+async def root():
+    return {"message": "欢迎使用汉字书法识别模型，请使用 POST /upload 接口上传图片。"}
+
+
+@app.get("/health")
+async def health_check():
+    """健康检查接口"""
+    status = "healthy" if recognizer else "unhealthy"
+    return {"status": status, "model_loaded": recognizer is not None}
+
+
+if __name__ == "__main__":
+    import uvicorn
+
+    uvicorn.run(app, host="0.0.0.0", port=8000, log_level="info")

requirements.txt

@@ -1,2 +1,7 @@
 fastapi
 uvicorn[standard]
+torch
+torchvision
+Pillow
+opencv-python
+numpy