feat: add CUDA GPU acceleration to vision_node preprocessing

Move resize, BGR2GRAY, and GaussianBlur to GPU via cv2.cuda, with
graceful CPU fallback when CUDA is unavailable.

workspace/src/algorithm_pkg/algorithm_pkg/vision_node.py

@@ -31,12 +31,45 @@ class VisionNode(Node):
             Point, '/vision/target', 10
         )
 
+        # GPU acceleration setup
+        self._use_cuda = False
+        try:
+            if cv2.cuda.getCudaEnabledDeviceCount() > 0:
+                self._use_cuda = True
+                self._gpu_frame = cv2.cuda_GpuMat()
+                self._gpu_blurred = cv2.cuda_GpuMat()
+                self._gaussian_filter = cv2.cuda.createGaussianFilter(
+                    cv2.CV_8UC1, cv2.CV_8UC1, (5, 5), 1)
+        except AttributeError:
+            pass
+
         self.get_logger().info(
-            'VisionNode ready - subscribing to /camera/image_raw'
+            'VisionNode ready - %s, subscribing to /camera/image_raw'
+            % ('CUDA GPU acceleration enabled'
+               if self._use_cuda else 'CPU pipeline')
         )
 
         self.start_time = 0
 
+    def _preprocess(self, cv_image):
+        """Return blurred grayscale at half resolution."""
+        if self._use_cuda:
+            return self._gpu_preprocess(cv_image)
+        scaled = cv2.resize(cv_image, None, fx=0.5, fy=0.5,
+                            interpolation=cv2.INTER_AREA)
+        gray = cv2.cvtColor(scaled, cv2.COLOR_BGR2GRAY)
+        return cv2.GaussianBlur(gray, (5, 5), 1)
+
+    def _gpu_preprocess(self, cv_image):
+        self._gpu_frame.upload(cv_image)
+        gpu_scaled = cv2.cuda.resize(
+            self._gpu_frame, None, fx=0.5, fy=0.5,
+            interpolation=cv2.INTER_AREA)
+        gpu_gray = cv2.cuda.cvtColor(gpu_scaled, cv2.COLOR_BGR2GRAY)
+        self._gpu_blurred.create(gpu_gray.size(), gpu_gray.type())
+        self._gaussian_filter.apply(gpu_gray, self._gpu_blurred)
+        return self._gpu_blurred.download()
+
     def _image_callback(self, msg):
         try:
             encoding = msg.encoding
@@ -46,21 +79,14 @@ class VisionNode(Node):
 
             cv_image = self._bridge.imgmsg_to_cv2(msg, desired_encoding='bgr8')
 
-            # 分辨率缩小一半，提高处理速度
-            scaled = cv2.resize(cv_image, None, fx=0.5, fy=0.5,
-                                interpolation=cv2.INTER_AREA)
+            gauss_image = self._preprocess(cv_image)
 
-            # 预处理：灰度图 + 高斯模糊 (去噪)
-            gray_image = cv2.cvtColor(scaled, cv2.COLOR_BGR2GRAY)
-            gauss_image = cv2.GaussianBlur(gray_image, (5, 5), 1)
-
-            # Otsu 二值化（替代 Canny，更稳健）
+            # Otsu 二值化
             _, binary = cv2.threshold(
                 gauss_image, 0, 255,
-                cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU
-            )
+                cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)
 
-            # 形态学闭运算：先膨胀后腐蚀，连接断裂区域、去除噪点
+            # 形态学闭运算
             kernel = np.ones((3, 3), np.uint8)
             dilated = cv2.dilate(binary, kernel, iterations=1)
             eroded = cv2.erode(dilated, kernel, iterations=1)
@@ -105,13 +131,13 @@ class VisionNode(Node):
                 if moments['m00'] > 0:
                     cx = moments['m10'] / moments['m00']
                     cy = moments['m01'] / moments['m00']
-                    h, w = scaled.shape[:2]
+                    h, w = gauss_image.shape[:2]
                     error_x = (cx - w / 2) / (w / 2)
                     error_y = (cy - h / 2) / (h / 2)
 
                     target_msg = Point()
                     target_msg.x = error_x
-                    target_msg.y = error_y
+                    target_msg.y = -error_y
                     target_msg.z = 0.0
                     self._target_publisher.publish(target_msg)