Additional ghost train found

Author: MrEricSir

lib/train_detector.py

@@ -862,7 +862,8 @@ def _detect_symbols(self, hsv, h, w, gray):
         candidate_mask = cv2.bitwise_and(candidate_mask, cv2.bitwise_not(cyan_mask))
         candidate_mask = cv2.bitwise_and(candidate_mask, cv2.bitwise_not(red_mask))
 
-        # Morphology
+        # Morphology — keep pre-close mask to verify symbol solidity
+        pre_close_mask = candidate_mask.copy()
         kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (3, 3))
         candidate_mask = cv2.morphologyEx(candidate_mask, cv2.MORPH_CLOSE, kernel)
 
@@ -887,6 +888,14 @@ def _detect_symbols(self, hsv, h, w, gray):
             if aspect < 1.5 or aspect > 3.5:
                 continue
 
+            # Reject noise connected by morphological closing: real train symbols
+            # are solidly colored (fill ≥ 0.7 before closing), while noise from
+            # scattered pixels has much lower fill (~0.3-0.4).
+            pre_pixels = cv2.countNonZero(pre_close_mask[y:y+ch, x:x+cw])
+            fill_ratio = pre_pixels / max(cw * ch, 1)
+            if fill_ratio < 0.7:
+                continue
+
             cx, cy = x + cw // 2, y + ch // 2
             track = 'upper' if cy < upper_track_y else 'lower'
 

scripts/review-archive.py

@@ -504,8 +504,7 @@ def main():
         print(f'No images directory found at {image_dir}')
         sys.exit(1)
 
-    filter_reason = effective_reason if args.skip_download else None
-    entries = collect_images(image_dir, reason_filter=filter_reason)
+    entries = collect_images(image_dir, reason_filter=effective_reason)
     if not entries:
         print('No archive images found.')
         sys.exit(0)

tests/baseline_delay_summaries.json

@@ -121,6 +121,10 @@
         "Eastbound service not running between Montgomery and Embarcadero",
         "Eastbound backup at Civic Center (4 trains)"
       ]
+    },
+    "muni_snapshot_20260224_082751.jpg": {
+      "status": "red",
+      "delay_summaries": []
     }
   }
 }

tests/baseline_trains.json

@@ -217,6 +217,7 @@
   "train_free_images": {
     "muni_snapshot_20260124_015604.jpg": {"max_false_positives": 10},
     "muni_snapshot_20260124_041839.jpg": {"max_false_positives": 20},
-    "muni_snapshot_20260219_closed.jpg": {"max_false_positives": 1}
+    "muni_snapshot_20260219_closed.jpg": {"max_false_positives": 1},
+    "muni_snapshot_20260224_082751.jpg": {"max_false_positives": 0}
   }
 }

tests/images/muni_snapshot_20260224_082751.jpg

@@ -50,6 +50,7 @@
     ("muni_snapshot_20251212_002351.jpg", "red", "Maintenance display - only non-revenue trains detected"),
     ("muni_snapshot_20260124_020104.jpg", "red", "Not operating - overnight"),
     ("muni_snapshot_20260218_013611.jpg", "red", "Overnight - non-revenue train 2206X, red track segments"),
+    ("muni_snapshot_20260224_082751.jpg", "red", "Overnight 12:27am - no revenue trains, false positive at YBR area"),
 ]