add detection rate metric

horizon-metrics.py

@@ -65,7 +65,7 @@ Examples:
                      [[0.0, 0.523573113510805], [1.0, 0.47642688648919496]]]
 
 
-    >>> module = evaluate.load("SEA-AI/horizon-metrics")
+    >>> module = evaluate.load("SEA-AI/horizon-metrics", roll_threshold=0.5, pitch_threshold=0.1, vertical_fov_degrees=25.6, height=512)
     >>> module.add(predictions=ground_truth_points, references=prediction_points)
     >>> module.compute()
     >>> {'average_slope_error': 0.014823194839790999,
@@ -111,16 +111,20 @@ class HorizonMetrics(evaluate.Metric):
                  roll_threshold=0.5,
                  pitch_threshold=0.1,
                  vertical_fov_degrees=25.6,
+                 height=512,
                  **kwargs):
 
         super().__init__(**kwargs)
+
         self.slope_threshold = roll_to_slope(roll_threshold)
         self.midpoint_threshold = pitch_to_midpoint(pitch_threshold,
                                                     vertical_fov_degrees)
         self.predictions = None
         self.ground_truth_det = None
-        self.slope_error_list = None
-        self.midpoint_error_list = None
+        self.slope_error_list = []
+        self.midpoint_error_list = []
+        self.height = height
+        self.vertical_fov_degrees = vertical_fov_degrees
 
     def _info(self):
         """
@@ -163,15 +167,6 @@ class HorizonMetrics(evaluate.Metric):
 
         self.predictions = predictions
         self.ground_truth_det = references
-        self.slope_error_list = []
-        self.midpoint_error_list = []
-
-        for annotated_horizon, proposed_horizon in zip(self.ground_truth_det,
-                                                       self.predictions):
-            slope_error, midpoint_error = calculate_horizon_error(
-                annotated_horizon, proposed_horizon)
-            self.slope_error_list.append(slope_error)
-            self.midpoint_error_list.append(midpoint_error)
 
     def _compute(self, *, predictions, references, **kwargs):
         """
@@ -180,6 +175,32 @@ class HorizonMetrics(evaluate.Metric):
         Returns:
             float: The computed horizon error.
         """
-        return calculate_horizon_error_across_sequence(
+
+        # calculate erros and store values in slope_error_list and midpoint_error_list
+        for annotated_horizon, proposed_horizon in zip(self.ground_truth_det,
+                                                       self.predictions):
+
+            if annotated_horizon is None or proposed_horizon is None:
+                continue
+
+            slope_error, midpoint_error = calculate_horizon_error(
+                annotated_horizon, proposed_horizon)
+            self.slope_error_list.append(slope_error)
+            self.midpoint_error_list.append(midpoint_error)
+
+        # calculate slope errors, midpoint errors and jumps
+        result = calculate_horizon_error_across_sequence(
             self.slope_error_list, self.midpoint_error_list,
-            self.slope_threshold, self.midpoint_threshold)
+            self.slope_threshold, self.midpoint_threshold,
+            self.vertical_fov_degrees, self.height)
+
+        # calulcate detection rate
+        detected_horizon_count = len(
+            self.predictions) - self.predictions.count(None)
+        detected_gt_count = len(
+            self.ground_truth_det) - self.ground_truth_det.count(None)
+
+        detection_rate = detected_horizon_count / detected_gt_count
+        result['detection_rate'] = detection_rate
+
+        return result