utils.py

import cv2

# COCO dataset class labels
CLASS_NAMES = [
    "person", "bicycle", "car", "motorcycle", "airplane", "bus", "train", "truck",
    "boat", "traffic light", "fire hydrant", "stop sign", "parking meter", "bench",
    "bird", "cat", "dog", "horse", "sheep", "cow", "elephant", "bear", "zebra",
    "giraffe", "backpack", "umbrella", "handbag", "tie", "suitcase", "frisbee",
    "skis", "snowboard", "sports ball", "kite", "baseball bat", "baseball glove",
    "skateboard", "surfboard", "tennis racket", "bottle", "wine glass", "cup",
    "fork", "knife", "spoon", "bowl", "banana", "apple", "sandwich", "orange",
    "broccoli", "carrot", "hot dog", "pizza", "donut", "cake", "chair", "couch",
    "potted plant", "bed", "dining table", "toilet", "tv", "laptop", "mouse",
    "remote", "keyboard", "cell phone", "microwave", "oven", "toaster", "sink",
    "refrigerator", "book", "clock", "vase", "scissors", "teddy bear", "hair drier",
    "toothbrush"
]

def draw_tracks(frame, tracks, class_names):
    for track in tracks:
        if not track.is_confirmed():
            continue
        track_id = track.track_id
        ltrb = track.to_ltrb()
        x1, y1, x2, y2 = map(int, ltrb)

        class_id = getattr(track, 'det_class', None)
        class_label = class_names[class_id] if class_id is not None and class_id < len(class_names) else "Object"
        label = f"ID {track_id}: {class_label}"

        cv2.rectangle(frame, (x1, y1), (x2, y2), (0, 255, 0), 2)
        cv2.putText(frame, label, (x1, y1 - 10),
                    cv2.FONT_HERSHEY_SIMPLEX, 0.6, (0, 255, 255), 2)
    return frame