fix: 摄像头每次拍照后立即关闭释放资源，添加全黑检测和重试机制

camera.py

@@ -3,6 +3,7 @@
 """
 import cv2
 import datetime
+import time
 from pathlib import Path
 from config import config_mgr
 
@@ -13,17 +14,30 @@ class CameraCapture:
     def __init__(self):
         self.camera_index = config_mgr.get('camera_index', 0)
         self.cap = None
+        self._closed = True
+        self._release_time = 0
         
     def open(self):
         """打开摄像头"""
-        if self.cap is None or not self.cap.isOpened():
+        if self.cap is not None and self.cap.isOpened():
+            return True
+        
+        # 确保之前的摄像头已完全关闭
+        if not self._closed:
+            self.close()
+            import time
+            time.sleep(0.5)  # 等待摄像头完全释放
+        
         self.camera_index = config_mgr.get('camera_index', 0)
         self.cap = cv2.VideoCapture(self.camera_index, cv2.CAP_DSHOW)  # Windows DirectShow
         if not self.cap.isOpened():
             raise Exception(f"无法打开摄像头 {self.camera_index}")
+        
         # 设置分辨率
         self.cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1280)
         self.cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 720)
+        
+        self._closed = False
         return self.cap.isOpened()
     
     def close(self):
@@ -31,50 +45,103 @@ class CameraCapture:
         if self.cap is not None:
             self.cap.release()
             self.cap = None
+            self._closed = True
+            self._release_time = time.time()
     
-    def capture(self, save_path=None):
-        """拍照并保存（按日期文件夹组织）
+    def capture(self, save_path=None, retry_count=3):
+        """拍照并保存（每次拍照后自动关闭摄像头）
+        
+        Args:
+            save_path: 保存路径
+            retry_count: 重试次数
             
         Returns:
             dict: {'success': bool, 'path': str, 'timestamp': str, 'date_folder': str, 'error': str}
         """
+        for attempt in range(retry_count):
             try:
+                # 每次拍照都重新打开摄像头
                 self.open()
                 
                 # 等待摄像头稳定（Windows 上需要预热）
-            for _ in range(5):
-                self.cap.read()
+                time.sleep(0.5)
                 
-            ret, frame = self.cap.read()
+                # 读取帧（丢弃前几帧确保稳定）
+                for _ in range(5):
+                    ret, _ = self.cap.read()
                     if not ret:
+                        self.close()
+                        if attempt < retry_count - 1:
+                            print(f"[Camera] 预热失败，重试 {attempt + 2}/{retry_count}")
+                            time.sleep(1)
+                            continue
+                        return {'success': False, 'error': '摄像头预热失败'}
+                
+                # 拍照
+                ret, frame = self.cap.read()
+                
+                # 立即关闭摄像头释放资源
+                self.close()
+                
+                if not ret or frame is None:
+                    if attempt < retry_count - 1:
+                        print(f"[Camera] 捕获失败，重试 {attempt + 2}/{retry_count}")
+                        time.sleep(1)
+                        continue
                     return {'success': False, 'error': '无法捕获图像'}
                 
-            # 获取当前日期
-            now = datetime.datetime.now()
-            date_str = now.strftime('%Y-%m-%d')
-            timestamp = now.strftime('%Y%m%d_%H%M%S')
+                # 检查图像是否全黑
+                if self._is_black_frame(frame):
+                    if attempt < retry_count - 1:
+                        print(f"[Camera] 全黑图像，重试 {attempt + 2}/{retry_count}")
+                        time.sleep(2)
+                        continue
+                    return {'success': False, 'error': '捕获到全黑图像'}
                 
-            # 获取按日期的保存目录
-            date_folder = config_mgr.get_images_dir(date_str)
+                # 成功，保存图片
+                now = datetime.datetime.now()
+                timestamp = now.strftime('%Y%m%d_%H%M%S')
+                date_str = now.strftime('%Y-%m-%d')
                 
                 if save_path is None:
+                    date_folder = config_mgr.get_images_dir(date_str)
                     filename = f"capture_{timestamp}.jpg"
                     save_path = date_folder / filename
                 
-            # 保存图片
                 cv2.imwrite(str(save_path), frame, [cv2.IMWRITE_JPEG_QUALITY, 90])
                 
+                print(f"[Camera] 拍照成功: {save_path.name}")
+                
                 return {
                     'success': True,
                     'path': str(save_path),
                     'timestamp': timestamp,
-                'date_folder': date_str,
+                    'date_folder': save_path.parent.name,
                     'filename': save_path.name
                 }
                 
             except Exception as e:
+                self.close()
+                if attempt < retry_count - 1:
+                    print(f"[Camera] 异常: {e}, 重试 {attempt + 2}/{retry_count}")
+                    time.sleep(2)
+                    continue
                 return {'success': False, 'error': str(e)}
         
+        return {'success': False, 'error': '重试后仍失败'}
+    
+    def _is_black_frame(self, frame):
+        """检测图像是否全黑"""
+        if frame is None:
+            return True
+        
+        # 计算平均亮度
+        gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
+        mean_brightness = cv2.mean(gray)[0]
+        
+        # 如果平均亮度小于 5，视为全黑
+        return mean_brightness < 5
+    
     def get_camera_info(self):
         """获取摄像头信息"""
         try:
@@ -82,14 +149,16 @@ class CameraCapture:
             width = int(self.cap.get(cv2.CAP_PROP_FRAME_WIDTH))
             height = int(self.cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
             fps = int(self.cap.get(cv2.CAP_PROP_FPS))
+            self.close()
             return {
                 'index': self.camera_index,
                 'width': width,
                 'height': height,
                 'fps': fps,
-                'status': 'opened'
+                'status': 'ok'
             }
         except Exception as e:
+            self.close()
             return {
                 'index': self.camera_index,
                 'status': 'error',