TRACK_MATCH_THRESH

CONTROL.md

@@ -0,0 +1,179 @@
+# Runtime Control — Start/Stop Counting
+
+The counter can pause and resume object detection & counting **on the fly**,
+without restarting the process. There are three interchangeable ways to control
+it, and they all converge on a single source of truth: the **control file**.
+
+- **Control file** — a small JSON file the counter polls.
+- **TCP control socket** — line commands over the network that update the file.
+- **Dashboard button** — a COUNTING ON/OFF toggle that writes the file via its API.
+
+When counting is **OFF**, the counter skips inference entirely (no detection, no
+counting, lower CPU/NPU load), the video/live stream keeps running, and a
+`COUNTING PAUSED` badge is drawn on the frame. When **ON**, normal counting
+resumes.
+
+---
+
+## 1. Enable runtime control
+
+Runtime control is opt-in. In your `.env`:
+
+```ini
+# Master switch — required for ALL control methods (file, socket, dashboard).
+CONTROL_ENABLED=true
+
+# Shared control file. MUST be identical for the counter and the dashboard.
+CONTROL_FILE=/opt/bytetrack-counter/control.json
+
+# Counting state on startup / when the control file does not exist yet.
+CONTROL_DEFAULT_COUNTING=true
+
+# How often (seconds) the counter re-reads the control file.
+CONTROL_POLL_SEC=1.0
+```
+
+When `CONTROL_ENABLED=false`, the counter always counts, the control file is
+ignored, and the dashboard hides the toggle button.
+
+> Changes take effect within `CONTROL_POLL_SEC` seconds (default 1s), because the
+> counter re-reads the file on a timer.
+
+---
+
+## 2. Control file
+
+### Format
+
+```json
+{ "counting": true }
+```
+
+- `"counting": true`  → counting **ON**
+- `"counting": false` → counting **OFF** (paused)
+
+The counter creates this file on startup (seeded from `CONTROL_DEFAULT_COUNTING`)
+if it does not exist. All writers (counter, dashboard, socket) write it
+**atomically** (temp file + rename), so readers never see a half-written file.
+
+### Toggle by editing the file
+
+Pause counting:
+
+```bash
+printf '{"counting": false}\n' > /opt/bytetrack-counter/control.json
+```
+
+Resume counting:
+
+```bash
+printf '{"counting": true}\n' > /opt/bytetrack-counter/control.json
+```
+
+Check current state:
+
+```bash
+cat /opt/bytetrack-counter/control.json
+```
+
+> Use the exact path from your `CONTROL_FILE` setting. If you write it by hand,
+> keep it valid JSON — an unreadable file falls back to `CONTROL_DEFAULT_COUNTING`.
+
+---
+
+## 3. TCP control socket
+
+The socket lets you toggle counting over the network. It updates the same control
+file, so changes still apply within `CONTROL_POLL_SEC`.
+
+### Enable
+
+```ini
+# Requires CONTROL_ENABLED=true as well.
+CONTROL_SOCKET_ENABLED=true
+
+# 127.0.0.1 = local only. Use 0.0.0.0 to allow remote clients.
+CONTROL_SOCKET_HOST=127.0.0.1
+
+# TCP port.
+CONTROL_SOCKET_PORT=5090
+```
+
+### Commands
+
+Newline-terminated, case-insensitive. One connection can send multiple commands.
+
+| Command                    | Effect                        | Reply                 |
+|----------------------------|-------------------------------|-----------------------|
+| `START` / `RESUME` / `ON`  | Counting ON                   | `OK counting=on`      |
+| `STOP` / `PAUSE` / `OFF`   | Counting OFF                  | `OK counting=off`     |
+| `TOGGLE`                   | Flip current state            | `OK counting=on/off`  |
+| `STATUS` / `GET`           | Report state (no change)      | `OK counting=on/off`  |
+| *(anything else)*          | —                             | `ERR unknown command` |
+
+### Examples
+
+Using `nc` (netcat):
+
+```bash
+printf 'STOP\n'   | nc 127.0.0.1 5090
+printf 'START\n'  | nc 127.0.0.1 5090
+printf 'TOGGLE\n' | nc 127.0.0.1 5090
+printf 'STATUS\n' | nc 127.0.0.1 5090
+```
+
+Using bash `/dev/tcp` (no netcat needed):
+
+```bash
+exec 3<>/dev/tcp/127.0.0.1/5090
+printf 'STATUS\n' >&3
+head -n1 <&3
+exec 3>&-
+```
+
+Python client:
+
+```python
+import socket
+
+def control(cmd, host="127.0.0.1", port=5090):
+    with socket.create_connection((host, port), timeout=2) as s:
+        s.sendall((cmd + "\n").encode())
+        return s.recv(256).decode().strip()
+
+print(control("STATUS"))  # OK counting=on
+print(control("STOP"))    # OK counting=off
+```
+
+> **Security:** the socket has **no authentication**. Keep `CONTROL_SOCKET_HOST`
+> on `127.0.0.1`, or restrict access with a firewall / trusted network if you
+> bind to `0.0.0.0`.
+
+---
+
+## 4. Dashboard button
+
+When `CONTROL_ENABLED=true`, the dashboard header shows a **COUNTING ON/OFF**
+button (green when on, red when off). Clicking it flips the state immediately.
+
+The dashboard must point at the **same** `CONTROL_FILE` as the counter (set it in
+the dashboard's environment too). The dashboard exposes:
+
+- `GET /api/control` → `{ "enabled": true, "counting": true }`
+- `POST /api/control` with body `{ "counting": false }` → writes the control file
+  (returns `403` if `CONTROL_ENABLED=false`)
+
+---
+
+## Notes & behavior
+
+- **Single source of truth:** the socket and dashboard both write the control
+  file; the counter reacts only to the file. This avoids race conditions between
+  control methods.
+- **Latency:** expect up to `CONTROL_POLL_SEC` (default 1s) between issuing a
+  command and the counter reacting.
+- **Live stream keeps running** while paused, so you still see the camera feed
+  with the `COUNTING PAUSED` overlay.
+- **Shared path requirement:** counter and dashboard must use the same
+  `CONTROL_FILE`. If they run on different machines, use the TCP socket (or a
+  shared network path) instead.

config.env.example

@@ -39,6 +39,11 @@ SCORE_SIGMOID=false
 # --- Detection ---
 # Confidence threshold – detections below this are discarded before NMS
 CONF=0.3
+# NMS IoU threshold (0-1): boxes overlapping the top box by more than this are
+# suppressed. RAISE it (e.g. 0.6-0.7) if two close/overlapping objects are being
+# merged into one and their separate boxes get suppressed. Lower = more aggressive
+# merging. Default 0.45.
+NMS_IOU=0.45
 
 # --- ByteTrack tracking ---
 # Detections with score >= this get priority matching in the first association stage
@@ -138,12 +143,47 @@ CROSS_SNAPSHOT_CLEANUP_SEC=60
 
 # --- Rate / performance ---
 # Enable motion detection pre-filter: skip inference on frames with no movement
-# (true/false, default: false). When enabled, frames below MOTION_THRESHOLD are
-# skipped, saving NPU/CPU load.
+# (true/false, default: false), saving NPU/CPU load. Motion is measured by the
+# fraction of pixels that changed (localized-motion aware), NOT the whole-frame
+# average, so an object entering the edge of the frame is detected immediately.
 MOTION_DETECTION_ENABLED=false
-# Mean absolute pixel difference threshold (0–255) to consider a frame as having
-# motion. Lower = more sensitive. Default 5.0.
+# Per-pixel intensity change (0-255) for a pixel to count as "moved". Lower = more
+# sensitive to subtle movement. Default 25.
+MOTION_PIXEL_DELTA=25
+# Fraction of frame pixels (0-1) that must change to trigger inference. Lower =
+# more sensitive / detects smaller or farther objects sooner. Default 0.002 (0.2%).
+MOTION_MIN_AREA_FRAC=0.002
+# Heartbeat: always run inference at least every N frames even with no detected
+# motion, so a slow or barely-moving object is never missed for long. Default 15.
+MOTION_HEARTBEAT_FRAMES=15
+# (Deprecated) old whole-frame mean-difference threshold; no longer used.
 MOTION_THRESHOLD=5.0
+
+# --- Runtime control (start/stop counting on the fly) ---
+# When true, the counter watches a JSON control file and pauses/resumes object
+# detection & counting based on its "counting" flag. The dashboard shows a
+# COUNTING ON/OFF toggle button that writes this file. When false, the counter
+# always counts and the dashboard hides the toggle. (true/false, default: false)
+CONTROL_ENABLED=false
+# Path to the shared control file. MUST be identical for the counter and the
+# dashboard so the toggle takes effect. Contents: {"counting": true|false}
+CONTROL_FILE=/opt/bytetrack-counter/control.json
+# Counting state to assume on startup / when the control file does not exist yet.
+CONTROL_DEFAULT_COUNTING=true
+# How often (seconds) the counter re-reads the control file. Default 1.0.
+CONTROL_POLL_SEC=1.0
+# Optional TCP control socket (requires CONTROL_ENABLED=true). Lets you toggle
+# counting over the network with line commands. It updates the same control file,
+# so changes apply within CONTROL_POLL_SEC. (true/false, default: false)
+#   Commands (newline-terminated): START|RESUME|ON, STOP|PAUSE|OFF, TOGGLE, STATUS
+#   e.g.  printf 'STOP\n' | nc 127.0.0.1 5090
+CONTROL_SOCKET_ENABLED=false
+# Bind address for the control socket. Use 127.0.0.1 for local-only, 0.0.0.0 to
+# allow remote clients (no auth — protect with firewall / trusted network).
+CONTROL_SOCKET_HOST=127.0.0.1
+# Control socket TCP port.
+CONTROL_SOCKET_PORT=5090
+
 # Sliding window in seconds for computing the crossing rate (objects/minute)
 RATE_WINDOW_SEC=60
 # Number of frames to discard at startup to let the stream buffer stabilise

counter_dashboard.py

@@ -38,6 +38,10 @@ LIVE_STREAM_FRAME_PATH = os.getenv("LIVE_STREAM_FRAME_PATH", "/dev/shm/jetson-co
 CROSS_SNAPSHOT_DIR = os.getenv("CROSS_SNAPSHOT_DIR", f"{_DEFAULT_DIR}/snapshots")
 SAVE_DETECT_SNAPSHOT = os.getenv("SAVE_DETECT_SNAPSHOT", "false").lower() == "true"
 
+CONTROL_ENABLED = os.getenv("CONTROL_ENABLED", "false").lower() == "true"
+CONTROL_FILE = os.getenv("CONTROL_FILE", f"{_DEFAULT_DIR}/control.json")
+CONTROL_DEFAULT_COUNTING = os.getenv("CONTROL_DEFAULT_COUNTING", "true").lower() == "true"
+
 SITE_NAME = os.getenv("SITE_NAME", "LIVE")
 
 DASHBOARD_PORT = int(os.getenv("DASHBOARD_PORT", "5000"))
@@ -56,6 +60,12 @@ def api_live_video():
             try:
                 with open(LIVE_STREAM_FRAME_PATH, "rb") as f:
                     jpeg = f.read()
+                if not jpeg or len(jpeg) < 2 or jpeg[:2] != b"\xff\xd8":
+                    consecutive_fails += 1
+                    if consecutive_fails >= MAX_FAILS:
+                        return
+                    time.sleep(0.05)
+                    continue
                 consecutive_fails = 0
                 yield (b"--frame\r\n"
                        b"Content-Type: image/jpeg\r\n\r\n" + jpeg + b"\r\n")
@@ -201,7 +211,59 @@ def get_counting_date(dt=None, cutoff_str=CUTOFF_TIME):
 
 @app.route("/")
 def index():
-    return render_template("dashboard.html", site_name=SITE_NAME, show_detect=SAVE_DETECT_SNAPSHOT)
+    return render_template(
+        "dashboard.html",
+        site_name=SITE_NAME,
+        show_detect=SAVE_DETECT_SNAPSHOT,
+        control_enabled=CONTROL_ENABLED,
+    )
+
+
+def _read_counting_flag():
+    try:
+        with open(CONTROL_FILE, "r", encoding="utf-8") as f:
+            return bool(json.load(f).get("counting", CONTROL_DEFAULT_COUNTING))
+    except FileNotFoundError:
+        return CONTROL_DEFAULT_COUNTING
+    except Exception:
+        return CONTROL_DEFAULT_COUNTING
+
+
+def _write_counting_flag(counting):
+    os.makedirs(os.path.dirname(CONTROL_FILE) or ".", exist_ok=True)
+    tmp = f"{CONTROL_FILE}.tmp"
+    with open(tmp, "w", encoding="utf-8") as f:
+        json.dump({"counting": bool(counting)}, f)
+    os.replace(tmp, CONTROL_FILE)
+
+
+@app.route("/api/control", methods=["GET"])
+def api_control_get():
+    return jsonify({
+        "success": True,
+        "enabled": CONTROL_ENABLED,
+        "counting": _read_counting_flag(),
+    })
+
+
+@app.route("/api/control", methods=["POST"])
+def api_control_set():
+    if not CONTROL_ENABLED:
+        return jsonify({"success": False, "error": "Runtime control is disabled (set CONTROL_ENABLED=true)"}), 403
+    data = request.get_json(silent=True) or {}
+    if "counting" not in data:
+        return jsonify({"success": False, "error": "Missing 'counting' field"}), 400
+    try:
+        counting = bool(data["counting"])
+        _write_counting_flag(counting)
+        return jsonify({"success": True, "counting": counting})
+    except Exception as e:
+        return jsonify({"success": False, "error": str(e)}), 500
+
+
+@app.route("/snapshots")
+def snapshots_page():
+    return render_template("snapshots.html", site_name=SITE_NAME, show_detect=SAVE_DETECT_SNAPSHOT)
 
 
 @app.route("/api/current-counter")
@@ -455,15 +517,16 @@ def export_daily_xlsx():
     wb = Workbook()
     ws = wb.active
     ws.title = "Daily Counters"
-    _style_header(ws, [("A", "Date"), ("B", "Total"), ("C", "In"), ("D", "Out"), ("E", "First Count"), ("F", "Last Count")])
+    _style_header(ws, [("A", "Date"), ("B", "Total"), ("C", "In"), ("D", "Out"), ("E", "Diff (In-Out)"), ("F", "First Count"), ("G", "Last Count")])
 
     for r_idx, row in enumerate(rows, 2):
         ws.cell(row=r_idx, column=1, value=row["counting_date"])
         ws.cell(row=r_idx, column=2, value=row["total_count"])
         ws.cell(row=r_idx, column=3, value=row["total_in"])
         ws.cell(row=r_idx, column=4, value=row["total_out"])
-        ws.cell(row=r_idx, column=5, value=row["start_time"])
-        ws.cell(row=r_idx, column=6, value=row["end_time"])
+        ws.cell(row=r_idx, column=5, value=(row["total_in"] or 0) - (row["total_out"] or 0))
+        ws.cell(row=r_idx, column=6, value=row["start_time"])
+        ws.cell(row=r_idx, column=7, value=row["end_time"])
 
     _auto_width(ws)
     filename = f"{SITE_NAME}_daily_records_{datetime.now().strftime('%Y%m%d_%H%M%S')}.xlsx"

counter_live_rknn.py

@@ -7,8 +7,11 @@ Uses ByteTrack (Kalman filter + two-stage IoU association) for tracking.
 import numpy as np
 import cv2
 import csv
+import json
 import os
 import signal
+import socket
+import threading
 import time
 from collections import deque
 from datetime import datetime
@@ -39,6 +42,7 @@ LINE_Y2_FRAC = float(os.getenv("LINE_Y2_FRAC", "0.66"))
 IMGSZ = int(os.getenv("IMGSZ", "320"))
 HALF = os.getenv("HALF", "false").lower() == "true"
 CONF = float(os.getenv("CONF", "0.3"))
+NMS_IOU = float(os.getenv("NMS_IOU", "0.45"))
 DEVICE = int(os.getenv("DEVICE", "0"))
 
 # RKNN NPU core mask
@@ -111,6 +115,29 @@ IS_LIVE = SOURCE.lower().startswith(("rtsp://", "http://"))
 
 MOTION_DETECTION_ENABLED = os.getenv("MOTION_DETECTION_ENABLED", "false").lower() == "true"
 MOTION_THRESHOLD = float(os.getenv("MOTION_THRESHOLD", "5.0"))
+# Per-pixel intensity change (0-255) for a pixel to count as "moved".
+MOTION_PIXEL_DELTA = int(os.getenv("MOTION_PIXEL_DELTA", "25"))
+# Fraction of frame pixels that must change (0-1) to trigger inference. Small,
+# so an object entering the edge of the frame is detected immediately.
+MOTION_MIN_AREA_FRAC = float(os.getenv("MOTION_MIN_AREA_FRAC", "0.002"))
+# Always run inference at least every N frames even if no motion (heartbeat), so a
+# slow/stationary object is never missed for long.
+MOTION_HEARTBEAT_FRAMES = int(os.getenv("MOTION_HEARTBEAT_FRAMES", "15"))
+
+# --- Runtime control (toggle counting on/off on the fly) ---
+# When enabled, the process watches a small JSON control file and honors its
+# "counting" flag. Set false to always count (ignore the control file).
+CONTROL_ENABLED = os.getenv("CONTROL_ENABLED", "false").lower() == "true"
+CONTROL_FILE = os.getenv("CONTROL_FILE", f"{OUTPUT_DIR}/control.json")
+# Whether counting is active on startup when no control file exists yet.
+CONTROL_DEFAULT_COUNTING = os.getenv("CONTROL_DEFAULT_COUNTING", "true").lower() == "true"
+# Re-read the control file at most every N seconds.
+CONTROL_POLL_SEC = float(os.getenv("CONTROL_POLL_SEC", "1.0"))
+# Optional TCP control socket. When enabled, the counter listens for line-based
+# commands so counting can be toggled over the network (in addition to the file).
+CONTROL_SOCKET_ENABLED = os.getenv("CONTROL_SOCKET_ENABLED", "false").lower() == "true"
+CONTROL_SOCKET_HOST = os.getenv("CONTROL_SOCKET_HOST", "127.0.0.1")
+CONTROL_SOCKET_PORT = int(os.getenv("CONTROL_SOCKET_PORT", "5090"))
 
 CROSS_FLASH_FRAMES = 12
 POPUP_LIFETIME = 20
@@ -414,6 +441,7 @@ class ByteTracker:
                 cost_mat = 1.0 - iou_mat
                 matches = _greedy_match(cost_mat, threshold=1.0 - self.match_thresh)
 
+                matched_det_idx = set()
                 for di, ti in matches:
                     det_global = int(high_idx[di])
                     orig_idx = int(remain_orig_idx[det_global])
@@ -423,6 +451,30 @@ class ByteTracker:
                     det_to_track[orig_idx] = track_pool[ti].track_id
                     tracked_map[track_pool[ti].track_id] = (track_pool[ti].get_cx(), track_pool[ti].get_cy())
                     match_pairs_high.append((det_global, ti))
+                    matched_det_idx.add(di)
+
+                # --- second pass: any unmatched high-score detection tries to
+                #     pair with ANY track that overlaps above threshold, even one
+                #     that already has a match. This prevents a close/overlapping
+                #     object from spawning a spurious new ID when the greedy 1:1
+                #     match paired its detection elsewhere. ---
+                for di in range(len(high_dets)):
+                    if di in matched_det_idx:
+                        continue
+                    best_ti = None
+                    best_iou = 0.0
+                    for ti in range(num_tracks):
+                        if iou_mat[di, ti] > best_iou and iou_mat[di, ti] >= self.match_thresh:
+                            best_iou = iou_mat[di, ti]
+                            best_ti = ti
+                    if best_ti is not None:
+                        det_global = int(high_idx[di])
+                        orig_idx = int(remain_orig_idx[det_global])
+                        track_pool[best_ti].update(dets[det_global])
+                        track_pool[best_ti].hit_streak = max(1, track_pool[best_ti].hit_streak)
+                        matched_track_idx.add(best_ti)
+                        det_to_track[orig_idx] = track_pool[best_ti].track_id
+                        tracked_map[track_pool[best_ti].track_id] = (track_pool[best_ti].get_cx(), track_pool[best_ti].get_cy())
 
             unmatched_tracks = [
                 t for t in range(num_tracks) if t not in matched_track_idx
@@ -693,6 +745,93 @@ def now_str():
     return datetime.now().strftime("%Y-%m-%d %H:%M:%S")
 
 
+def read_counting_flag(default=True):
+    """Read the 'counting' flag from the control file. Returns default on any error."""
+    try:
+        with open(CONTROL_FILE, "r", encoding="utf-8") as f:
+            data = json.load(f)
+        return bool(data.get("counting", default))
+    except FileNotFoundError:
+        return default
+    except Exception:
+        return default
+
+
+def write_control_file(counting):
+    """Create/update the control file atomically (used to seed defaults)."""
+    try:
+        Path(CONTROL_FILE).parent.mkdir(parents=True, exist_ok=True)
+        tmp = f"{CONTROL_FILE}.tmp"
+        with open(tmp, "w", encoding="utf-8") as f:
+            json.dump({"counting": bool(counting)}, f)
+        os.replace(tmp, CONTROL_FILE)
+    except Exception as exc:
+        print(f"[{now_str()}] Failed to write control file: {exc}")
+
+
+def start_control_socket():
+    """Start a TCP server for runtime control. Commands (newline-terminated):
+        START | RESUME | ON   -> counting on
+        STOP | PAUSE | OFF    -> counting off
+        TOGGLE                -> flip
+        STATUS | GET          -> report current state
+    It writes the shared control file, so the main loop's file-poll applies it.
+    Returns the server socket (call .close() to stop)."""
+    srv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    srv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    srv.bind((CONTROL_SOCKET_HOST, CONTROL_SOCKET_PORT))
+    srv.listen(5)
+
+    def handle(conn, addr):
+        with conn:
+            conn.settimeout(30)
+            try:
+                buf = b""
+                while not shutdown_requested:
+                    try:
+                        chunk = conn.recv(256)
+                    except socket.timeout:
+                        break
+                    if not chunk:
+                        break
+                    buf += chunk
+                    while b"\n" in buf:
+                        line, buf = buf.split(b"\n", 1)
+                        cmd = line.decode("utf-8", "ignore").strip().upper()
+                        if not cmd:
+                            continue
+                        current = read_counting_flag(CONTROL_DEFAULT_COUNTING)
+                        if cmd in ("START", "RESUME", "ON"):
+                            write_control_file(True)
+                            resp = "OK counting=on"
+                        elif cmd in ("STOP", "PAUSE", "OFF"):
+                            write_control_file(False)
+                            resp = "OK counting=off"
+                        elif cmd == "TOGGLE":
+                            write_control_file(not current)
+                            resp = f"OK counting={'off' if current else 'on'}"
+                        elif cmd in ("STATUS", "GET"):
+                            resp = f"OK counting={'on' if current else 'off'}"
+                        else:
+                            resp = "ERR unknown command"
+                        conn.sendall((resp + "\n").encode("utf-8"))
+            except Exception:
+                pass
+
+    def loop():
+        print(f"Control socket listening on {CONTROL_SOCKET_HOST}:{CONTROL_SOCKET_PORT}")
+        while not shutdown_requested:
+            try:
+                conn, addr = srv.accept()
+            except OSError:
+                break
+            t = threading.Thread(target=handle, args=(conn, addr), daemon=True)
+            t.start()
+
+    threading.Thread(target=loop, daemon=True).start()
+    return srv
+
+
 def open_capture(source):
     if source.lower().startswith(("rtsp://", "http://")):
         os.environ["OPENCV_FFMPEG_CAPTURE_OPTIONS"] = RTSP_FFMPEG_OPTIONS
@@ -1047,6 +1186,7 @@ def run():
         core_mask=CORE_MASK,
         imgsz=IMGSZ,
         conf=CONF,
+        iou=NMS_IOU,
         num_classes=NUM_CLASSES,
         score_sigmoid=SCORE_SIGMOID,
     )
@@ -1078,12 +1218,30 @@ def run():
     frame_idx = 0
     inf_ms = 0.0
     prev_gray = None
+    frames_since_infer = 0
     video_writer = None
     crossing_times = deque()
     counter_in = 0
     counter_out = 0
     last_snapshot_cleanup = 0.0
 
+    counting_active = True
+    last_control_poll = 0.0
+    control_socket = None
+    if CONTROL_ENABLED:
+        if not Path(CONTROL_FILE).exists():
+            write_control_file(CONTROL_DEFAULT_COUNTING)
+        counting_active = read_counting_flag(CONTROL_DEFAULT_COUNTING)
+        print(
+            f"Runtime control enabled | file={CONTROL_FILE} | "
+            f"counting={'ON' if counting_active else 'OFF'}"
+        )
+        if CONTROL_SOCKET_ENABLED:
+            try:
+                control_socket = start_control_socket()
+            except Exception as exc:
+                print(f"[{now_str()}] Failed to start control socket: {exc}")
+
     cap, w, h, fps = connect_stream(SOURCE)
     if cap is None:
         store.shutdown()
@@ -1133,20 +1291,35 @@ def run():
         cross_events_frame = []
         detect_events_frame = []
 
+        if CONTROL_ENABLED and (now - last_control_poll) >= CONTROL_POLL_SEC:
+            last_control_poll = now
+            new_flag = read_counting_flag(CONTROL_DEFAULT_COUNTING)
+            if new_flag != counting_active:
+                counting_active = new_flag
+                print(f"[{now_str()}] Counting {'RESUMED' if counting_active else 'PAUSED'} via control file")
+
         skip_inference = False
-        if MOTION_DETECTION_ENABLED:
+        if not counting_active:
+            skip_inference = True
+        elif MOTION_DETECTION_ENABLED:
             gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
             if prev_gray is not None:
                 diff = cv2.absdiff(gray, prev_gray)
-                mean_diff = cv2.mean(diff)[0]
-                skip_inference = mean_diff < MOTION_THRESHOLD
+                moved = int(np.count_nonzero(diff > MOTION_PIXEL_DELTA))
+                moved_frac = moved / diff.size
+                skip_inference = moved_frac < MOTION_MIN_AREA_FRAC
+                if frames_since_infer >= MOTION_HEARTBEAT_FRAMES:
+                    skip_inference = False
             prev_gray = gray
 
         detections = []
         if not skip_inference:
+            frames_since_infer = 0
             inf_start = time.time()
             detections = model(frame)
             inf_ms = inf_ms * 0.9 + (time.time() - inf_start) * 1000 * 0.1
+        else:
+            frames_since_infer += 1
 
         object_boxes_xyxy = []
         object_scores = []
@@ -1350,6 +1523,14 @@ def run():
         )
         popups = draw_popups(frame, popups, frame_idx)
 
+        if CONTROL_ENABLED and not counting_active:
+            badge = "COUNTING PAUSED"
+            (bw, bh), _ = cv2.getTextSize(badge, cv2.FONT_HERSHEY_SIMPLEX, 0.6, 2)
+            bx = w // 2 - bw // 2
+            overlay_rect(frame, bx - 14, 48, bx + bw + 14, 48 + bh + 18, C_PANEL, alpha=0.75)
+            cv2.rectangle(frame, (bx - 14, 48), (bx + bw + 14, 48 + bh + 18), C_ACCENT, 2)
+            cv2.putText(frame, badge, (bx, 48 + bh + 6), cv2.FONT_HERSHEY_SIMPLEX, 0.6, C_ACCENT, 2, cv2.LINE_AA)
+
         for flash_store in (
             object_cross_flash1, object_cross_flash2,
         ):
@@ -1367,11 +1548,14 @@ def run():
         if LIVE_STREAM_ENABLED and frame_idx % LIVE_STREAM_EVERY_N == 0:
             try:
                 Path(LIVE_STREAM_FRAME_PATH).parent.mkdir(parents=True, exist_ok=True)
-                _, jpeg = cv2.imencode(
+                ok, jpeg = cv2.imencode(
                     ".jpg", frame, [cv2.IMWRITE_JPEG_QUALITY, LIVE_STREAM_QUALITY]
                 )
-                with open(LIVE_STREAM_FRAME_PATH, "wb") as f:
-                    f.write(jpeg.tobytes())
+                if ok:
+                    tmp_path = f"{LIVE_STREAM_FRAME_PATH}.tmp"
+                    with open(tmp_path, "wb") as f:
+                        f.write(jpeg.tobytes())
+                    os.replace(tmp_path, LIVE_STREAM_FRAME_PATH)
             except Exception:
                 pass
 
@@ -1418,6 +1602,11 @@ def run():
         video_writer.release()
     if cross_logger:
         cross_logger.close()
+    if control_socket is not None:
+        try:
+            control_socket.close()
+        except Exception:
+            pass
     model.release()
     store.shutdown()
 

debug.txt

@@ -0,0 +1 @@
+Jul 14 22:15:51 frigate-karung-masuk-tuang-dev python[2390681]: , 5806, 5808, 5809, 5810, 5811, 5812, 5813, 5814, 5815, 5816, 5817, 5818, 5819, 5820, 5821, 5822, 5824, 5825, 5826, 5827, 5828, 5829, 5830, 5831, 5832, 5833, 5834, 5835, 5837, 5838, 5839, 5840, 5843, 5844, 5845, 5846, 5847, 5848, 5849, 5854, 5855, 5856, 5857, 5858, 5860, 5861, 5862, 5863, 5864, 5865, 5866, 5867, 5868, 5870, 5871, 5872, 5873, 5874, 5876, 5877, 5878, 5879, 5880, 5881, 5882, 5883, 5884, 5885, 5886, 5887, 5888, 5889, 5892, 5893, 5894, 5895, 5896, 5897, 5899, 5900, 5901, 5902, 5903, 5904, 5907, 5908, 5909, 5910, 5911, 5912, 5913, 5914, 5915, 5916, 5917, 5918, 5919, 5920, 5921, 5922, 5923, 5925, 5926, 5927, 5928, 5929, 5930, 5931, 5932, 5935, 5936, 5937, 5938, 5939, 5942, 5943, 5944, 5945, 5946, 5947, 5948, 5949, 5950, 5951, 5953, 5954, 5955, 5956, 5957, 5958, 5959, 5961, 5962, 5963, 5964, 5965, 5966, 5967, 5968, 5969, 5970, 5971, 5972, 5974, 5975, 5976, 5977, 5978, 5979, 5980, 5982, 5983, 5985, 5986, 5987, 5988, 5989, 5990, 5991, 5992, 5993, 5995, 5996, 5997, 5998, 5999, 6000, 6001, 6002, 6003, 6004, 6005, 6007, 6008, 6009, 6010, 6011, 6012, 6013, 6014, 6015, 6020, 6021, 6022, 6023, 6024, 6025, 6026, 6030, 6031, 6032, 6033, 6034, 6035, 6036, 6037, 6038, 6042, 6043, 6044, 6045, 6046, 6047, 6048, 6050, 6051, 6052, 6056, 6057, 6058, 6059, 6060, 6061, 6062, 6063, 6064, 6065, 6068, 6069, 6070, 6071, 6072, 6073, 6074, 6075, 6076, 6080, 6081, 6082, 6083, 6084, 6085, 6087, 6088, 6089, 6090, 6091, 6092, 6093, 6094, 6095, 6096, 6097, 6098, 6099, 6100, 6102, 6103, 6104, 6105, 6106, 6107, 6108, 6115, 6116, 6117, 6118, 6119, 6120, 6121, 6122, 6123, 6124, 6131, 6132, 6133, 6134, 6135, 6136, 6137, 6138, 6139, 6140, 6141, 6142, 6143, 6144, 6145, 6146, 6147, 6148, 6149, 6150, 6151, 6152, 6154, 6155, 6156, 6157, 6158, 6159, 6160, 6161, 6162, 6163, 6164, 6165, 6166, 6168, 6169, 6170, 6171, 6172, 6173, 6175, 6176, 6177, 6178, 6179, 6180, 6181, 6183, 6184, 6185, 6186, 6190, 6191, 6192, 6193, 6194, 6195, 6196, 6197, 6198, 6199, 6200, 6201, 6202, 6203, 6204, 6205, 6206, 6207, 6208, 6209, 6210, 6212, 6213, 6214, 6215, 6216, 6217, 6218, 6219, 6220, 6227, 6228, 6229, 6230, 6231, 6232, 6233, 6234, 6235, 6236, 6237, 6239, 6240, 6241, 6242, 6243, 6244, 6245, 6246, 6247, 6250, 6251, 6252, 6253, 6254, 6255, 6256, 6257, 6258, 6259, 6260, 6261, 6267, 6268, 6269, 6270, 6271, 6272, 6273, 6274, 6275, 6276, 6277, 6278, 6280, 6281, 6282, 6283, 6284, 6285, 6286, 6287, 6288, 6290, 6291, 6292, 6293, 6294, 6295, 6296, 6297, 6298, 6303, 6304, 6305, 6306, 6307, 6308, 6309, 6310, 6311, 6312, 6313, 6314, 6315, 6316, 6317, 6318, 6319, 6320, 6321, 6322, 6323, 6324, 6325, 6327, 6328, 6329, 6330, 6331, 6332, 6333, 6334, 6335, 6336, 6338, 6339, 6340, 6341, 6342, 6344, 6345, 6346, 6347, 6348, 6349, 6350, 6351, 6352, 6353, 6355, 6356, 6357, 6358, 6359, 6360, 6361, 6366, 6367, 6368, 6369, 6370, 6371, 6372, 6373, 6374, 6375, 6376, 6377, 6378, 6379, 6380, 6381, 6382, 6383, 6384, 6385, 6386, 6387, 6388, 6389, 6390, 6391, 6392, 6393, 6394, 6395, 6396, 6397, 6398, 6401, 6402, 6403, 6404, 6405, 6406, 6407, 6408, 6409, 6410, 6411, 6412, 6415, 6416, 6417, 6418, 6419, 6420, 6421, 6422, 6428, 6429, 6430, 6431, 6440, 6441, 6442, 6443, 6444, 6445, 6446, 6447, 6450, 6451, 6452, 6453, 6454, 6455, 6456, 6457, 6458, 6459, 6460, 6461, 6464, 6465, 6466, 6467, 6468, 6469, 6470, 6471, 6472, 6475, 6476, 6477, 6478, 6479, 6480, 6481, 6482, 6483, 6484, 6485, 6486, 6487, 6488, 6489, 6490, 6491, 6492, 6493, 6494, 6495, 6496, 6498, 6499, 6500, 6502, 6503, 6504, 6505, 6506, 6507, 6508, 6509, 6510, 6511, 6512, 6513, 6514, 6515, 6516, 6517, 6518, 6519, 6520, 6521, 6522, 6523, 6528, 6529, 6530, 6531, 6532, 6533, 6534, 6535, 6538, 6539, 6540, 6541, 6542, 6546, 6547, 6548, 6549, 6550, 6551, 6552, 6553, 6554, 6555, 6556, 6557, 6558, 6559, 6560, 6561, 6562, 6563, 6564, 6565, 6566, 6567, 6568, 6569, 6570, 6571, 6572, 6573, 6574, 6575, 6576, 6577, 6580, 6581, 6582, 6583, 6584, 6585, 6586, 6587, 6588, 6589, 6590, 6591, 6592, 6593, 6594, 6595, 6596, 6597, 6598, 6599, 6600, 6601, 6602, 6603, 6605, 6606, 6607, 6608, 6609, 6610, 6611, 6614, 6615, 6616, 6617, 6619, 6620, 6621, 6622, 6623, 6624, 6625, 6626, 6627, 6628, 6630, 6631, 6632, 6633, 6634, 6636, 6642, 6643, 6644, 6645, 6646, 6647, 6648, 6649, 6650, 6652, 6653, 6654, 6655, 6656, 6657, 6658, 6659, 6660, 6661, 6662, 6663, 6664, 6668, 6669, 6670, 6671, 6672, 6673, 6674, 6676, 6677, 6678, 6679, 6680, 6681, 6682, 6683, 6684, 6685, 6686, 6687, 6688, 6694, 6695, 6696, 6697, 6698, 6699, 6700, 6701, 6702, 6703, 6704, 6705, 6706, 6707, 6708, 6709, 6710, 6711, 6712, 6713, 6714, 6722, 6723, 6724, 6725, 6726, 6727, 6728, 6729, 6730, 6731, 6732, 6733, 6738, 6739, 6740, 6741, 6742, 6743, 6744, 6745, 6746, 6747, 6748, 6749, 6750, 6754, 6755, 6756, 6757, 6758, 6759, 6760, 6761, 6762, 6763, 6764, 6765, 6766, 6767, 6768, 6769, 6772, 6773, 6774, 6777, 6778, 6779, 6780, 6781, 6782, 6788, 6789, 6790, 6791, 6792, 6793, 6794, 6795, 6797, 6798, 6799, 6800, 6801, 6802, 6803, 6804, 6805, 6806, 6Line truncated

env.example

@@ -27,7 +27,7 @@ IMGSZ=320
 # Use FP16 inference on NPU (true/false); currently unused in ByteTrack variant
 HALF=false
 # NPU core mask: 1=core0, 2=core1, 3=core0+core1, 7=all three
-CORE_MASK=7
+CORE_MASK=1
 # Compute device index (reserved; not used at runtime)
 DEVICE=0
 
@@ -97,7 +97,7 @@ CROSS_CSV=/tmp/crossings.csv
 # Enable motion detection pre-filter: skip inference on frames with no movement
 # (true/false, default: false). When enabled, frames below MOTION_THRESHOLD are
 # skipped, saving NPU/CPU load.
-MOTION_DETECTION_ENABLED=false
+MOTION_DETECTION_ENABLED=true
 # Mean absolute pixel difference threshold (0–255) to consider a frame as having
 # motion. Lower = more sensitive. Default 5.0.
 MOTION_THRESHOLD=5.0
@@ -145,3 +145,6 @@ CURRENT_COUNTER_PATH=/tmp/bytetrack_current_counter.json
 SAVE_CROSS_SNAPSHOT=true
 CROSS_SNAPSHOT_DIR=/opt/zenai-kpc-snaps/snapshots
 CROSS_SNAPSHOT_CLEANUP_SEC=3600
+CROSS_SNAPSHOT_MAX_AGE_DAYS=3
+
+DEDUP_PX=-1

templates/dashboard.html

@@ -149,6 +149,19 @@
   }
   .theme-toggle:hover { border-color: var(--accent); background: var(--cell-bg); }
 
+  .nav-link {
+    display: inline-flex; align-items: center; gap: 6px;
+    background: none; border: 1px solid var(--cell-border);
+    border-radius: 8px; padding: 7px 12px; cursor: pointer;
+    font-family: 'JetBrains Mono', monospace; font-size: 10px; letter-spacing: 1px;
+    color: var(--text-secondary); text-decoration: none;
+    transition: border-color 0.3s, color 0.3s, background 0.3s;
+  }
+  .nav-link:hover { border-color: var(--accent); color: var(--text-primary); background: var(--cell-bg); }
+  .nav-link.active { border-color: var(--accent); color: var(--accent); }
+  .nav-link.counting-on { border-color: rgba(0,255,136,0.5); color: var(--accent4); }
+  .nav-link.counting-off { border-color: rgba(255,45,120,0.5); color: var(--accent3); }
+
   /* Section title */
   .section-title {
     font-family: 'Orbitron', sans-serif; font-size: 13px; font-weight: 600; letter-spacing: 2px;
@@ -406,55 +419,6 @@
   }
   .table-toolbar .toolbar-group { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
 
-  /* Snapshot gallery */
-  .snapshot-grid {
-    display: grid;
-    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
-    gap: 14px;
-  }
-  .snap-card {
-    background: var(--cell-bg);
-    border: 1px solid var(--cell-border); border-radius: 12px;
-    overflow: hidden; cursor: pointer;
-    transition: border-color 0.2s, transform 0.15s;
-  }
-  .snap-card:hover { border-color: var(--accent); transform: translateY(-2px); }
-  .snap-thumb {
-    width: 100%; aspect-ratio: 4 / 3; object-fit: cover; display: block;
-    background: #000;
-  }
-  .snap-info { padding: 8px 10px; }
-  .snap-info .si-top {
-    display: flex; align-items: center; justify-content: space-between; margin-bottom: 4px;
-  }
-  .snap-kind {
-    font-size: 8px; font-weight: 700; letter-spacing: 1px; text-transform: uppercase;
-    padding: 2px 8px; border-radius: 8px;
-  }
-  .snap-kind.in { background: rgba(0,255,136,0.12); color: var(--accent4); }
-  .snap-kind.out { background: rgba(255,45,120,0.12); color: var(--accent3); }
-  .snap-kind.detect { background: rgba(0,240,255,0.10); color: var(--accent); }
-  .snap-tid {
-    font-family: 'Orbitron', sans-serif; font-size: 11px; font-weight: 700;
-    color: var(--text-primary);
-  }
-  .snap-time { font-size: 9px; color: var(--text-secondary); }
-
-  .snap-lightbox {
-    position: relative;
-    background: var(--bg-surface);
-    border: 1px solid var(--border-glow); border-radius: var(--radius);
-    padding: 14px; max-width: 92vw; max-height: 90vh;
-    display: flex; flex-direction: column; align-items: center;
-  }
-  .snap-lightbox img {
-    max-width: 88vw; max-height: 78vh; border-radius: 10px; display: block;
-  }
-  .snap-modal-meta {
-    margin-top: 10px; font-size: 11px; color: var(--text-secondary); letter-spacing: 1px;
-    text-align: center;
-  }
-
   .table-toolbar input[type="date"] {
     font-family: 'JetBrains Mono', monospace; font-size: 11px;
     background: var(--input-bg); color: var(--text-primary);
@@ -645,6 +609,8 @@
         <span class="dot"></span>
         <span>{{ site_name }}</span>
       </div>
+      <a class="nav-link" href="/snapshots" title="Snapshots"><i class="fas fa-images"></i> SNAPSHOTS</a>
+      {% if control_enabled %}<button class="nav-link" id="countingToggle" onclick="toggleCounting()" title="Start/stop counting"><i class="fas fa-power-off"></i> <span id="counting-label">--</span></button>{% endif %}
       <button class="theme-toggle" id="themeToggle" onclick="toggleTheme()" title="Toggle theme">☀️</button>
     </div>
   </div>
@@ -655,7 +621,7 @@
       <span class="s-chip live-chip-tag"><span class="ldot"></span>LIVE</span>
       <div class="s-icon primary"><i class="fas fa-calendar-day"></i></div>
       <div class="s-val" id="today-count">--</div>
-      <div class="s-label">Total Count Today</div>
+      <div class="s-label">Diff Today (In &minus; Out)</div>
       <div class="sub-cards">
         <div class="sub-card in">
           <div class="sc-head"><i class="fas fa-arrow-right-to-bracket"></i> In</div>
@@ -671,7 +637,7 @@
       <span class="s-chip info">Yesterday</span>
       <div class="s-icon warm"><i class="fas fa-history"></i></div>
       <div class="s-val" id="yesterday-count">--</div>
-      <div class="s-label">Total Count Yesterday</div>
+      <div class="s-label">Diff Yesterday (In &minus; Out)</div>
       <div class="sub-cards">
         <div class="sub-card in">
           <div class="sc-head"><i class="fas fa-arrow-right-to-bracket"></i> In</div>
@@ -749,8 +715,8 @@
           <div class="qs-left">
             <div class="qs-icon primary"><i class="fas fa-layer-group"></i></div>
             <div>
-              <div class="qs-label">Grand Total</div>
-              <div class="qs-sub">All time</div>
+              <div class="qs-label">Grand Diff</div>
+              <div class="qs-sub">All time (In &minus; Out)</div>
             </div>
           </div>
           <span class="qs-val" id="grand-total">--</span>
@@ -805,7 +771,7 @@
         <thead>
           <tr>
             <th style="padding-left:4px;">Date</th>
-            <th>Total Count</th>
+            <th>Diff (In &minus; Out)</th>
             <th>In</th>
             <th>Out</th>
             <th style="padding-right:4px;">Status</th>
@@ -818,47 +784,9 @@
     </div>
   </div>
 
-  <!-- Snapshots -->
-  <div class="table-panel">
-    <div class="table-toolbar">
-      <div>
-        <span class="section-title" style="margin-bottom:0;">&#9673; Crossing Snapshots</span>
-        <div style="font-size:10px;color:var(--text-secondary);letter-spacing:1px;">Detected & counted frames — correlate by track ID</div>
-      </div>
-      <div class="toolbar-group">
-        <div class="chart-filters" id="snap-filters">
-          <button class="active" data-kind="all" onclick="loadSnapshots('all')">ALL</button>
-          <button data-kind="in" onclick="loadSnapshots('in')">IN</button>
-          <button data-kind="out" onclick="loadSnapshots('out')">OUT</button>
-          {% if show_detect %}<button data-kind="detect" onclick="loadSnapshots('detect')">DETECT</button>{% endif %}
-        </div>
-        <input type="date" id="snap-date-filter">
-        <button class="btn btn-primary" onclick="applySnapFilter()">FILTER</button>
-        <button class="btn btn-ghost" onclick="resetSnapFilter()">RESET</button>
-      </div>
-    </div>
-    <div id="snapshot-grid" class="snapshot-grid">
-      <!-- Populated by JS -->
-    </div>
-    <div id="snapshot-empty" style="display:none;text-align:center;padding:32px;color:var(--text-secondary);">
-      <div style="font-size:32px;opacity:0.2;margin-bottom:8px;">&#9635;</div>
-      <div style="font-size:10px;letter-spacing:1px;">NO SNAPSHOTS AVAILABLE</div>
-      <div style="font-size:9px;margin-top:6px;opacity:0.7;">Enable SAVE_CROSS_SNAPSHOT{% if show_detect %} / SAVE_DETECT_SNAPSHOT{% endif %} in counter .env</div>
-    </div>
-  </div>
-
   <div class="footer">Edge Nano Counter by ZenAi</div>
 </div>
 
-<!-- Snapshot lightbox -->
-<div class="modal-overlay hidden" id="snap-modal" onclick="closeSnapModal(event)">
-  <div class="snap-lightbox" id="snap-lightbox">
-    <button class="close-btn" onclick="closeSnapModal()" style="position:absolute;top:12px;right:12px;z-index:2;">&times;</button>
-    <img id="snap-modal-img" alt="Snapshot" />
-    <div class="snap-modal-meta" id="snap-modal-meta">--</div>
-  </div>
-</div>
-
 <script>
 // --- Theme ---
 (function() {
@@ -893,7 +821,6 @@ document.addEventListener('DOMContentLoaded', () => {
   loadChartData(7);
   loadRecentDays();
   resetFilter();
-  loadSnapshots('all');
 
   setInterval(() => {
     loadSummary();
@@ -904,20 +831,69 @@ document.addEventListener('DOMContentLoaded', () => {
     loadCurrentCounter();
   }, 2000);
 
-  setInterval(() => {
-    if (snapCurrentKind && !snapDateFilter) loadSnapshots(snapCurrentKind, true);
-  }, 15000);
+  if (document.getElementById('countingToggle')) {
+    loadControlState();
+    setInterval(loadControlState, 5000);
+  }
 });
 
+let countingActive = null;
+
+async function loadControlState() {
+  try {
+    const res = await fetch('/api/control');
+    const data = await res.json();
+    countingActive = !!data.counting;
+    renderCountingToggle();
+  } catch (err) { /* ignore */ }
+}
+
+function renderCountingToggle() {
+  const btn = document.getElementById('countingToggle');
+  const label = document.getElementById('counting-label');
+  if (!btn || !label) return;
+  if (countingActive) {
+    label.textContent = 'COUNTING ON';
+    btn.classList.add('counting-on');
+    btn.classList.remove('counting-off');
+  } else {
+    label.textContent = 'COUNTING OFF';
+    btn.classList.add('counting-off');
+    btn.classList.remove('counting-on');
+  }
+}
+
+async function toggleCounting() {
+  const next = !countingActive;
+  try {
+    const res = await fetch('/api/control', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ counting: next }),
+    });
+    const data = await res.json();
+    if (data.success) {
+      countingActive = !!data.counting;
+      renderCountingToggle();
+    } else {
+      alert('Control error: ' + (data.error || 'unknown'));
+    }
+  } catch (err) {
+    alert('Control request failed: ' + err.message);
+  }
+}
+
 async function loadCurrentCounter() {
   try {
     const res = await fetch('/api/current-counter');
     if (!res.ok) throw new Error('No active counter');
     const data = await res.json();
 
-    document.getElementById('today-count').textContent = (data.count || 0).toLocaleString();
-    document.getElementById('today-in').textContent = (data.count_in || 0).toLocaleString();
-    document.getElementById('today-out').textContent = (data.count_out || 0).toLocaleString();
+    const tin = data.count_in || 0;
+    const tout = data.count_out || 0;
+    document.getElementById('today-count').textContent = (tin - tout).toLocaleString();
+    document.getElementById('today-in').textContent = tin.toLocaleString();
+    document.getElementById('today-out').textContent = tout.toLocaleString();
   } catch (err) {
     document.getElementById('today-count').textContent = '0';
     document.getElementById('today-in').textContent = '0';
@@ -932,7 +908,7 @@ async function loadSummary() {
 
     document.getElementById('current-date').textContent = data.today.date;
 
-    document.getElementById('yesterday-count').textContent = data.yesterday.total_count.toLocaleString();
+    document.getElementById('yesterday-count').textContent = (data.yesterday.total_in - data.yesterday.total_out).toLocaleString();
     document.getElementById('yesterday-in').textContent = data.yesterday.total_in.toLocaleString();
     document.getElementById('yesterday-out').textContent = data.yesterday.total_out.toLocaleString();
 
@@ -942,7 +918,7 @@ async function loadSummary() {
     document.getElementById('best-count').textContent = data.best_day.count.toLocaleString();
     document.getElementById('best-date').textContent = data.best_day.date || '--';
 
-    document.getElementById('grand-total').textContent = data.all_time.grand_total.toLocaleString();
+    document.getElementById('grand-total').textContent = (data.all_time.grand_in - data.all_time.grand_out).toLocaleString();
     document.getElementById('grand-in').textContent = data.all_time.grand_in.toLocaleString();
     document.getElementById('grand-out').textContent = data.all_time.grand_out.toLocaleString();
 
@@ -965,7 +941,7 @@ async function loadChartData(days) {
       const date = new Date(d.date);
       return date.toLocaleDateString('en-US', { weekday: 'short', day: 'numeric', month: 'short' });
     });
-    const counts = data.map(d => d.total_count);
+    const counts = data.map(d => d.total_in - d.total_out);
     const ins = data.map(d => d.total_in);
     const outs = data.map(d => d.total_out);
 
@@ -1001,7 +977,7 @@ async function loadChartData(days) {
             yAxisID: 'y'
           },
           {
-            label: 'Total',
+            label: 'Diff',
             data: counts,
             type: 'line',
             borderColor: 'rgba(0, 240, 255, 1)',
@@ -1072,7 +1048,7 @@ async function loadRecentDays() {
           </div>
         </div>
         <div style="text-align:right;">
-          <div class="ri-count">${d.total_count.toLocaleString()}</div>
+          <div class="ri-count">${(d.total_in - d.total_out).toLocaleString()}</div>
         </div>
       </div>
     `).join('');
@@ -1125,7 +1101,7 @@ function renderDailyTable(dates) {
             </div>
           </div>
         </td>
-        <td><span style="font-family:'Orbitron',sans-serif;font-size:15px;font-weight:700;">${d.total_count.toLocaleString()}</span></td>
+        <td><span style="font-family:'Orbitron',sans-serif;font-size:15px;font-weight:700;">${(d.total_in - d.total_out).toLocaleString()}</span></td>
         <td><span class="badge badge-green">${d.total_in.toLocaleString()}</span></td>
         <td><span class="badge badge-gray">${d.total_out.toLocaleString()}</span></td>
         <td style="padding-right:4px;">
@@ -1156,81 +1132,9 @@ function formatTime(isoString) {
 }
 
 document.addEventListener('keydown', (e) => {
-  if (e.key === 'Escape') { hideVideoError(); closeSnapModal(); }
+  if (e.key === 'Escape') { hideVideoError(); }
 });
 
-// --- Crossing Snapshots ---
-let snapCurrentKind = 'all';
-let snapDateFilter = '';
-
-async function loadSnapshots(kind, silent) {
-  if (kind !== undefined) snapCurrentKind = kind;
-  document.querySelectorAll('#snap-filters button').forEach(b => {
-    b.classList.toggle('active', b.dataset.kind === snapCurrentKind);
-  });
-
-  try {
-    let url = `/api/snapshots?kind=${snapCurrentKind}&limit=120`;
-    if (snapDateFilter) url += `&date=${snapDateFilter}`;
-    const res = await fetch(url);
-    const data = await res.json();
-    const grid = document.getElementById('snapshot-grid');
-    const empty = document.getElementById('snapshot-empty');
-    const items = (data && data.snapshots) || [];
-
-    if (items.length === 0) {
-      grid.innerHTML = '';
-      empty.style.display = 'block';
-      return;
-    }
-    empty.style.display = 'none';
-    grid.innerHTML = items.map(s => {
-      const url = `/api/snapshot-image/${s.file}`;
-      const t = new Date(s.timestamp);
-      const timeStr = t.toLocaleString('en-US', { hour12: false, month: 'short', day: 'numeric', hour: '2-digit', minute: '2-digit', second: '2-digit' });
-      const kindLabel = s.kind.toUpperCase();
-      return `
-        <div class="snap-card" onclick="openSnapModal('${url}','${kindLabel}',${s.track_id},'${timeStr}',${s.frame})">
-          <img class="snap-thumb" src="${url}" loading="lazy" alt="snapshot" />
-          <div class="snap-info">
-            <div class="si-top">
-              <span class="snap-kind ${s.kind}">${kindLabel}</span>
-              <span class="snap-tid">ID ${s.track_id}</span>
-            </div>
-            <div class="snap-time">${timeStr}</div>
-          </div>
-        </div>`;
-    }).join('');
-  } catch (err) {
-    if (!silent) console.error('Failed to load snapshots:', err);
-  }
-}
-
-function applySnapFilter() {
-  snapDateFilter = document.getElementById('snap-date-filter').value || '';
-  loadSnapshots(snapCurrentKind);
-}
-
-function resetSnapFilter() {
-  snapDateFilter = '';
-  document.getElementById('snap-date-filter').value = '';
-  snapCurrentKind = 'all';
-  loadSnapshots('all');
-}
-
-function openSnapModal(url, kind, tid, timeStr, frame) {
-  document.getElementById('snap-modal-img').src = url;
-  document.getElementById('snap-modal-meta').textContent =
-    `${kind} \u00b7 Track ID ${tid} \u00b7 Frame ${frame} \u00b7 ${timeStr}`;
-  document.getElementById('snap-modal').classList.remove('hidden');
-}
-
-function closeSnapModal(event) {
-  if (event && event.target && event.target.id !== 'snap-modal' && event.type === 'click') return;
-  document.getElementById('snap-modal').classList.add('hidden');
-  document.getElementById('snap-modal-img').src = '';
-}
-
 // --- Live Video Feed ---
 
 function toggleVideo() {

templates/snapshots.html

@@ -0,0 +1,489 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<title>ZenAI KPC Snapshots</title>
+<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css">
+<style>
+  @import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@300;400;500;700&family=Orbitron:wght@400;500;700;900&display=swap');
+
+  * { margin: 0; padding: 0; box-sizing: border-box; }
+
+  :root {
+    --bg-deep: #06080e;
+    --bg-surface: rgba(12, 16, 28, 0.9);
+    --border-glow: rgba(0, 240, 255, 0.12);
+    --accent: #00f0ff;
+    --accent2: #7b2fff;
+    --accent3: #ff2d78;
+    --accent4: #00ff88;
+    --text-primary: #dce2f0;
+    --text-secondary: #6b7394;
+    --glass: rgba(12, 16, 32, 0.7);
+    --cell-bg: rgba(255, 255, 255, 0.02);
+    --cell-border: rgba(255, 255, 255, 0.05);
+    --divider: rgba(255, 255, 255, 0.05);
+    --input-bg: rgba(0, 0, 0, 0.4);
+    --radius: 18px;
+  }
+
+  [data-theme="light"] {
+    --bg-deep: #eef1f5;
+    --bg-surface: rgba(255, 255, 255, 0.9);
+    --border-glow: rgba(0, 160, 200, 0.15);
+    --accent: #0090c0;
+    --accent2: #6a20e0;
+    --accent3: #d02060;
+    --accent4: #00a060;
+    --text-primary: #1a1d30;
+    --text-secondary: #5a6088;
+    --glass: rgba(255, 255, 255, 0.8);
+    --cell-bg: rgba(0, 0, 0, 0.03);
+    --cell-border: rgba(0, 0, 0, 0.06);
+    --divider: rgba(0, 0, 0, 0.06);
+    --input-bg: rgba(0, 0, 0, 0.05);
+  }
+
+  body {
+    font-family: 'JetBrains Mono', monospace;
+    background: var(--bg-deep);
+    color: var(--text-primary);
+    min-height: 100vh;
+    overflow-x: hidden;
+  }
+
+  .bg-grid {
+    position: fixed; inset: 0; z-index: 0;
+    background-image:
+      linear-gradient(rgba(0, 240, 255, 0.025) 1px, transparent 1px),
+      linear-gradient(90deg, rgba(0, 240, 255, 0.025) 1px, transparent 1px);
+    background-size: 64px 64px;
+    pointer-events: none;
+  }
+
+  .orb {
+    position: fixed; border-radius: 50%; filter: blur(140px); pointer-events: none;
+  }
+  .orb-1 { width: 600px; height: 600px; background: rgba(0, 240, 255, 0.04); top: -250px; left: -150px; }
+  .orb-2 { width: 500px; height: 500px; background: rgba(123, 47, 255, 0.04); bottom: -200px; right: -100px; }
+
+  .container {
+    position: relative; z-index: 1;
+    max-width: 1600px; margin: 0 auto; padding: 24px 20px;
+  }
+
+  .header {
+    display: flex; align-items: center; justify-content: space-between;
+    padding: 18px 28px; margin-bottom: 24px;
+    background: var(--glass);
+    backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px);
+    border: 1px solid var(--border-glow); border-radius: var(--radius);
+  }
+  .header-left { display: flex; align-items: center; gap: 14px; }
+  .logo-icon {
+    width: 44px; height: 44px;
+    background: linear-gradient(135deg, var(--accent), var(--accent2));
+    border-radius: 11px; font-size: 22px;
+    display: flex; align-items: center; justify-content: center;
+    box-shadow: 0 0 28px rgba(0, 240, 255, 0.35);
+  }
+  .header h1 {
+    font-family: 'Orbitron', sans-serif; font-size: 20px; font-weight: 700; letter-spacing: 3px;
+    background: linear-gradient(90deg, var(--accent), var(--accent2));
+    -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
+  }
+  .header-sub { font-size: 10px; color: var(--text-secondary); letter-spacing: 2px; text-transform: uppercase; }
+  .header-right { display: flex; align-items: center; gap: 14px; }
+  .live-chip {
+    display: flex; align-items: center; gap: 8px;
+    font-size: 9px; letter-spacing: 1.5px; padding: 5px 12px; border-radius: 12px;
+    font-weight: 600; text-transform: uppercase;
+    background: rgba(0, 255, 136, 0.1); color: var(--accent4);
+    border: 1px solid rgba(0, 255, 136, 0.2);
+  }
+  .live-chip .dot {
+    width: 7px; height: 7px; border-radius: 50%;
+    background: var(--accent4); box-shadow: 0 0 8px var(--accent4);
+    animation: blink 1.5s ease-in-out infinite;
+  }
+  @keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0.25; } }
+
+  .nav-link {
+    display: inline-flex; align-items: center; gap: 6px;
+    background: none; border: 1px solid var(--cell-border);
+    border-radius: 8px; padding: 7px 12px; cursor: pointer;
+    font-family: 'JetBrains Mono', monospace; font-size: 10px; letter-spacing: 1px;
+    color: var(--text-secondary); text-decoration: none;
+    transition: border-color 0.3s, color 0.3s, background 0.3s;
+  }
+  .nav-link:hover { border-color: var(--accent); color: var(--text-primary); background: var(--cell-bg); }
+  .nav-link.active { border-color: var(--accent); color: var(--accent); }
+
+  .theme-toggle {
+    background: none; border: 1px solid var(--cell-border);
+    border-radius: 8px; padding: 6px 10px; cursor: pointer;
+    font-size: 16px; line-height: 1;
+    transition: border-color 0.3s, background 0.3s;
+  }
+  .theme-toggle:hover { border-color: var(--accent); background: var(--cell-bg); }
+
+  .section-title {
+    font-family: 'Orbitron', sans-serif; font-size: 13px; font-weight: 600; letter-spacing: 2px;
+    background: linear-gradient(90deg, var(--accent), var(--accent2));
+    -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
+    display: inline-block;
+  }
+
+  .panel {
+    background: var(--glass);
+    backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px);
+    border: 1px solid var(--border-glow); border-radius: var(--radius);
+    padding: 24px 26px; margin-bottom: 24px;
+  }
+  .toolbar {
+    display: flex; align-items: center; justify-content: space-between;
+    margin-bottom: 20px; flex-wrap: wrap; gap: 12px;
+  }
+  .toolbar-group { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
+
+  .filters { display: flex; gap: 6px; }
+  .filters button {
+    font-family: 'JetBrains Mono', monospace; font-size: 10px;
+    letter-spacing: 1px; padding: 6px 14px; border-radius: 7px;
+    border: 1px solid var(--cell-border);
+    background: var(--cell-bg); color: var(--text-secondary);
+    cursor: pointer; transition: all 0.3s;
+  }
+  .filters button:hover { border-color: var(--accent); color: var(--text-primary); }
+  .filters button.active {
+    background: linear-gradient(135deg, var(--accent), var(--accent2));
+    color: #000; border-color: transparent; font-weight: 600;
+  }
+
+  input[type="date"] {
+    font-family: 'JetBrains Mono', monospace; font-size: 11px;
+    background: var(--input-bg); color: var(--text-primary);
+    border: 1px solid var(--cell-border); border-radius: 7px;
+    padding: 7px 12px; outline: none; transition: border-color 0.3s;
+  }
+  input[type="date"]:focus { border-color: var(--accent); }
+
+  .btn {
+    font-family: 'Orbitron', sans-serif; font-size: 10px; letter-spacing: 2px;
+    padding: 8px 16px; border-radius: 7px; cursor: pointer; font-weight: 600;
+    border: none; transition: opacity 0.3s, box-shadow 0.3s;
+  }
+  .btn-primary { background: linear-gradient(135deg, var(--accent), var(--accent2)); color: #000; }
+  .btn-primary:hover { opacity: 0.85; box-shadow: 0 0 20px rgba(0, 240, 255, 0.3); }
+  .btn-ghost {
+    background: var(--cell-bg); color: var(--text-secondary);
+    border: 1px solid var(--cell-border);
+  }
+  .btn-ghost:hover { border-color: var(--accent); color: var(--text-primary); }
+
+  .snapshot-grid {
+    display: grid;
+    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
+    gap: 14px;
+  }
+  .snap-card {
+    background: var(--cell-bg);
+    border: 1px solid var(--cell-border); border-radius: 12px;
+    overflow: hidden; cursor: pointer;
+    transition: border-color 0.2s, transform 0.15s;
+  }
+  .snap-card:hover { border-color: var(--accent); transform: translateY(-2px); }
+  .snap-thumb {
+    width: 100%; aspect-ratio: 4 / 3; object-fit: cover; display: block; background: #000;
+  }
+  .snap-info { padding: 8px 10px; }
+  .snap-info .si-top {
+    display: flex; align-items: center; justify-content: space-between; margin-bottom: 4px;
+  }
+  .snap-kind {
+    font-size: 8px; font-weight: 700; letter-spacing: 1px; text-transform: uppercase;
+    padding: 2px 8px; border-radius: 8px;
+  }
+  .snap-kind.in { background: rgba(0,255,136,0.12); color: var(--accent4); }
+  .snap-kind.out { background: rgba(255,45,120,0.12); color: var(--accent3); }
+  .snap-kind.detect { background: rgba(0,240,255,0.10); color: var(--accent); }
+  .snap-tid {
+    font-family: 'Orbitron', sans-serif; font-size: 11px; font-weight: 700; color: var(--text-primary);
+  }
+  .snap-time { font-size: 9px; color: var(--text-secondary); }
+
+  .empty {
+    text-align: center; padding: 48px; color: var(--text-secondary);
+  }
+  .empty .e-icon { font-size: 42px; opacity: 0.2; margin-bottom: 12px; }
+
+  .count-note { font-size: 10px; color: var(--text-secondary); letter-spacing: 1px; }
+
+  .modal-overlay {
+    position: fixed; inset: 0; z-index: 100;
+    background: rgba(0, 0, 0, 0.7);
+    backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
+    display: flex; align-items: center; justify-content: center; padding: 20px;
+  }
+  .modal-overlay.hidden { display: none; }
+  .close-btn {
+    background: none; border: 1px solid var(--cell-border); color: var(--text-secondary);
+    width: 32px; height: 32px; border-radius: 8px; cursor: pointer;
+    font-size: 16px; display: flex; align-items: center; justify-content: center;
+    transition: border-color 0.3s, color 0.3s;
+  }
+  .close-btn:hover { border-color: var(--accent3); color: var(--accent3); }
+  .snap-lightbox {
+    position: relative;
+    background: var(--bg-surface);
+    border: 1px solid var(--border-glow); border-radius: var(--radius);
+    padding: 14px; max-width: 92vw; max-height: 90vh;
+    display: flex; flex-direction: column; align-items: center;
+  }
+  .snap-lightbox img { max-width: 88vw; max-height: 78vh; border-radius: 10px; display: block; }
+  .snap-modal-meta {
+    margin-top: 10px; font-size: 11px; color: var(--text-secondary); letter-spacing: 1px; text-align: center;
+  }
+
+  ::-webkit-scrollbar { width: 6px; }
+  ::-webkit-scrollbar-track { background: transparent; }
+  ::-webkit-scrollbar-thumb { background: var(--text-secondary); border-radius: 3px; }
+
+  .footer {
+    margin-top: 24px; text-align: center;
+    font-size: 9px; letter-spacing: 2px; color: var(--text-secondary); text-transform: uppercase;
+  }
+
+  @media (max-width: 768px) {
+    .container { padding: 16px 12px; }
+    .header { flex-direction: column; gap: 10px; padding: 14px 20px; }
+    .header-right { flex-wrap: wrap; justify-content: center; }
+    .toolbar { flex-direction: column; align-items: flex-start; }
+  }
+</style>
+</head>
+<body>
+
+<div class="bg-grid"></div>
+<div class="orb orb-1"></div>
+<div class="orb orb-2"></div>
+
+<div class="container">
+  <!-- Header -->
+  <div class="header">
+    <div class="header-left">
+      <div class="logo-icon">&#9670;</div>
+      <div>
+        <h1>ZenAI KPC Snapshots</h1>
+        <div class="header-sub">Detected &amp; counted frames — correlate by track ID</div>
+      </div>
+    </div>
+    <div class="header-right">
+      <div class="live-chip">
+        <span class="dot"></span>
+        <span>{{ site_name }}</span>
+      </div>
+      <a class="nav-link" href="/"><i class="fas fa-gauge-high"></i> DASHBOARD</a>
+      <a class="nav-link active" href="/snapshots"><i class="fas fa-images"></i> SNAPSHOTS</a>
+      <button class="theme-toggle" id="themeToggle" onclick="toggleTheme()" title="Toggle theme">☀️</button>
+    </div>
+  </div>
+
+  <!-- Snapshots -->
+  <div class="panel">
+    <div class="toolbar">
+      <div>
+        <span class="section-title">&#9673; Crossing Snapshots</span>
+        <div class="count-note" id="snap-count-note">--</div>
+      </div>
+      <div class="toolbar-group">
+        <div class="filters" id="snap-filters">
+          <button class="active" data-kind="all" onclick="loadSnapshots('all')">ALL</button>
+          <button data-kind="in" onclick="loadSnapshots('in')">IN</button>
+          <button data-kind="out" onclick="loadSnapshots('out')">OUT</button>
+          {% if show_detect %}<button data-kind="detect" onclick="loadSnapshots('detect')">DETECT</button>{% endif %}
+        </div>
+        <input type="number" id="snap-tid-filter" placeholder="Track ID" min="0"
+               style="width:110px;font-family:'JetBrains Mono',monospace;font-size:11px;background:var(--input-bg);color:var(--text-primary);border:1px solid var(--cell-border);border-radius:7px;padding:7px 12px;outline:none;">
+        <input type="date" id="snap-date-filter">
+        <button class="btn btn-primary" onclick="applySnapFilter()">FILTER</button>
+        <button class="btn btn-ghost" onclick="resetSnapFilter()">RESET</button>
+      </div>
+    </div>
+    <div id="snapshot-grid" class="snapshot-grid">
+      <!-- Populated by JS -->
+    </div>
+    <div id="snap-sentinel" style="height:1px;"></div>
+    <div id="snapshot-empty" class="empty" style="display:none;">
+      <div class="e-icon">&#9635;</div>
+      <div style="font-size:10px;letter-spacing:1px;">NO SNAPSHOTS AVAILABLE</div>
+      <div style="font-size:9px;margin-top:6px;opacity:0.7;">Enable SAVE_CROSS_SNAPSHOT{% if show_detect %} / SAVE_DETECT_SNAPSHOT{% endif %} in counter .env</div>
+    </div>
+  </div>
+
+  <div class="footer">Edge Nano Counter by ZenAi</div>
+</div>
+
+<!-- Snapshot lightbox -->
+<div class="modal-overlay hidden" id="snap-modal" onclick="closeSnapModal(event)">
+  <div class="snap-lightbox" id="snap-lightbox">
+    <button class="close-btn" onclick="closeSnapModal()" style="position:absolute;top:12px;right:12px;z-index:2;">&times;</button>
+    <img id="snap-modal-img" alt="Snapshot" />
+    <div class="snap-modal-meta" id="snap-modal-meta">--</div>
+  </div>
+</div>
+
+<script>
+// --- Theme ---
+(function() {
+  const saved = localStorage.getItem('theme');
+  if (saved) document.documentElement.setAttribute('data-theme', saved);
+  updateToggleIcon();
+})();
+
+function toggleTheme() {
+  const el = document.documentElement;
+  const current = el.getAttribute('data-theme');
+  const next = current === 'light' ? '' : 'light';
+  if (next) el.setAttribute('data-theme', next);
+  else el.removeAttribute('data-theme');
+  localStorage.setItem('theme', next || 'dark');
+  updateToggleIcon();
+}
+
+function updateToggleIcon() {
+  const btn = document.getElementById('themeToggle');
+  if (!btn) return;
+  btn.textContent = document.documentElement.getAttribute('data-theme') === 'light' ? '🌙' : '☀️';
+}
+
+// --- Snapshots ---
+let snapCurrentKind = 'all';
+let snapDateFilter = '';
+let snapTidFilter = '';
+
+let snapItems = [];       // all fetched metadata
+let snapRendered = 0;     // how many cards are in the DOM
+const SNAP_BATCH = 60;    // cards added per chunk
+let snapObserver = null;
+
+document.addEventListener('DOMContentLoaded', () => {
+  const sentinel = document.getElementById('snap-sentinel');
+  snapObserver = new IntersectionObserver((entries) => {
+    if (entries.some(e => e.isIntersecting)) renderNextBatch();
+  }, { rootMargin: '600px' });
+  if (sentinel) snapObserver.observe(sentinel);
+
+  // Filter immediately when date changes or track ID is typed.
+  document.getElementById('snap-date-filter').addEventListener('change', applySnapFilter);
+  let tidDebounce = null;
+  document.getElementById('snap-tid-filter').addEventListener('input', () => {
+    clearTimeout(tidDebounce);
+    tidDebounce = setTimeout(applySnapFilter, 350);
+  });
+
+  loadSnapshots('all');
+  setInterval(() => {
+    if (snapCurrentKind && !snapDateFilter && !snapTidFilter) loadSnapshots(snapCurrentKind, true);
+  }, 15000);
+});
+
+function snapCardHtml(s) {
+  const imgUrl = `/api/snapshot-image/${s.file}`;
+  const t = new Date(s.timestamp);
+  const timeStr = t.toLocaleString('en-US', { hour12: false, month: 'short', day: 'numeric', hour: '2-digit', minute: '2-digit', second: '2-digit' });
+  const kindLabel = s.kind.toUpperCase();
+  return `
+    <div class="snap-card" onclick="openSnapModal('${imgUrl}','${kindLabel}',${s.track_id},'${timeStr}',${s.frame})">
+      <img class="snap-thumb" src="${imgUrl}" loading="lazy" decoding="async" alt="snapshot" />
+      <div class="snap-info">
+        <div class="si-top">
+          <span class="snap-kind ${s.kind}">${kindLabel}</span>
+          <span class="snap-tid">ID ${s.track_id}</span>
+        </div>
+        <div class="snap-time">${timeStr}</div>
+      </div>
+    </div>`;
+}
+
+function renderNextBatch() {
+  if (snapRendered >= snapItems.length) return;
+  const grid = document.getElementById('snapshot-grid');
+  const next = snapItems.slice(snapRendered, snapRendered + SNAP_BATCH);
+  grid.insertAdjacentHTML('beforeend', next.map(snapCardHtml).join(''));
+  snapRendered += next.length;
+  updateSnapNote();
+}
+
+function updateSnapNote() {
+  const note = document.getElementById('snap-count-note');
+  note.textContent = `Showing ${snapRendered} of ${snapItems.length}`;
+}
+
+async function loadSnapshots(kind, silent) {
+  if (kind !== undefined) snapCurrentKind = kind;
+  document.querySelectorAll('#snap-filters button').forEach(b => {
+    b.classList.toggle('active', b.dataset.kind === snapCurrentKind);
+  });
+
+  try {
+    let url = `/api/snapshots?kind=${snapCurrentKind}&limit=5000`;
+    if (snapDateFilter) url += `&date=${snapDateFilter}`;
+    if (snapTidFilter) url += `&track_id=${snapTidFilter}`;
+    const res = await fetch(url);
+    const data = await res.json();
+    const grid = document.getElementById('snapshot-grid');
+    const empty = document.getElementById('snapshot-empty');
+
+    snapItems = (data && data.snapshots) || [];
+    snapRendered = 0;
+    grid.innerHTML = '';
+
+    if (snapItems.length === 0) {
+      empty.style.display = 'block';
+      document.getElementById('snap-count-note').textContent = '';
+      return;
+    }
+    empty.style.display = 'none';
+    renderNextBatch();
+  } catch (err) {
+    if (!silent) console.error('Failed to load snapshots:', err);
+  }
+}
+
+function applySnapFilter() {
+  snapDateFilter = document.getElementById('snap-date-filter').value || '';
+  snapTidFilter = document.getElementById('snap-tid-filter').value || '';
+  loadSnapshots(snapCurrentKind);
+}
+
+function resetSnapFilter() {
+  snapDateFilter = '';
+  snapTidFilter = '';
+  document.getElementById('snap-date-filter').value = '';
+  document.getElementById('snap-tid-filter').value = '';
+  snapCurrentKind = 'all';
+  loadSnapshots('all');
+}
+
+function openSnapModal(url, kind, tid, timeStr, frame) {
+  document.getElementById('snap-modal-img').src = url;
+  document.getElementById('snap-modal-meta').textContent =
+    `${kind} \u00b7 Track ID ${tid} \u00b7 Frame ${frame} \u00b7 ${timeStr}`;
+  document.getElementById('snap-modal').classList.remove('hidden');
+}
+
+function closeSnapModal(event) {
+  if (event && event.target && event.target.id !== 'snap-modal' && event.type === 'click') return;
+  document.getElementById('snap-modal').classList.add('hidden');
+  document.getElementById('snap-modal-img').src = '';
+}
+
+document.addEventListener('keydown', (e) => {
+  if (e.key === 'Escape') closeSnapModal();
+});
+</script>
+
+</body>
+</html>