Raises an error if the tracking result is empty

Author: TimoK93

ctc_metrics/metrics/validation/valid.py

@@ -170,6 +170,25 @@ def no_empty_frames(
     return int(is_valid)
 
 
+def no_empty_tracking_result(
+        tracks: np.ndarray
+):
+    """
+    Checks if there is at least one detection in th results.
+
+    Args:
+        tracks: The tracks to inspect
+
+    Returns:
+        1 if there are detections, 0 otherwise.
+    """
+    is_valid = 1
+    warnings.warn("No tracks in result.", UserWarning)
+    if len(tracks) == 0:
+        is_valid = 0
+    return is_valid
+
+
 def valid(
         masks: list,
         tracks: np.ndarray,
@@ -195,6 +214,8 @@ def valid(
 
     """
     is_valid = 1
+    # If tracks is empty, the result is invalid
+    is_valid = no_empty_tracking_result(tracks)
     # Get the labels in each frame
     num_frames = max(tracks[:, 2].max() + 1, len(masks))
     frames = [[] for _ in range(num_frames)]

ctc_metrics/scripts/evaluate.py

@@ -151,6 +151,13 @@ def calculate_metrics(
     Returns:
         The results stored in a dictionary.
     """
+    # Check if results are valid
+    results = {x: None for x in metrics}
+    if not is_valid:
+        print("Invalid results!")
+        results["Valid"] = 0
+        return results
+
     # Create merge tracks
     if traj:
         new_tracks, new_labels, new_mapped = merge_tracks(
@@ -175,12 +182,6 @@ def calculate_metrics(
             )
 
     # Calculate metrics
-    results = {x: None for x in metrics}
-    if not is_valid:
-        print("Invalid results!")
-        results["Valid"] = 0
-        return results
-
     if "Valid" in metrics:
         results["Valid"] = is_valid
 

ctc_metrics/utils/filesystem.py

@@ -73,6 +73,8 @@ def read_tracking_file(
         return None
     with open(path, "r", encoding="utf-8") as f:
         lines = f.readlines()
+    if len(lines) == 0:
+        return np.zeros((0, 4))
     seperator = " " if " " in lines[0] else "\t"
     lines = [x.strip().split(seperator) for x in lines]
     lines = [[int(y) for y in x if y != ""] for x in lines]