Integrate detection service

rpi/hardware/camera/camera.py

@@ -0,0 +1,60 @@
+import cv2
+import threading
+import numpy as np
+from typing import Callable, Optional
+
+
+class Camera:
+    def __init__(self, index: int = 0):
+        self.index = index
+        self.cap: Optional[cv2.VideoCapture] = None
+        self.thread: Optional[threading.Thread] = None
+        self.stop_event = threading.Event()
+
+    def open(self):
+        if self.cap is None:
+            self.cap = cv2.VideoCapture(self.index)
+            if not self.cap.isOpened():
+                self.cap = None
+                raise RuntimeError("Could not open camera")
+
+    def close(self):
+        if self.cap is not None:
+            self.cap.release()
+            self.cap = None
+
+    def take_photo(self) -> np.ndarray:
+        self.open()
+        try:
+            ret, frame = self.cap.read()
+            if not ret:
+                raise RuntimeError("Failed to capture image")
+            return frame
+        finally:
+            self.close()
+
+    def start_capture(self, callback: Callable[[np.ndarray], None]):
+        if self.thread and self.thread.is_alive():
+            return
+
+        self.open()
+        self.stop_event.clear()
+
+        def loop():
+            while not self.stop_event.is_set():
+                ret, frame = self.cap.read()
+                if not ret:
+                    break
+                callback(frame)
+
+        self.thread = threading.Thread(target=loop, daemon=True)
+        self.thread.start()
+
+    def stop_capture(self):
+        self.stop_event.set()
+
+        self.close()
+
+        if self.thread:
+            self.thread.join(timeout=2)
+            self.thread = None