雙視訊人流計算
與趨勢分析系統

def update(self, objects_rect):
    objects_bbs_ids = []
    for rect in objects_rect:
        x, y, w, h = rect
        cx = (x + x + w) // 2   # 計算質心
        cy = (y + y + h) // 2

        same_object_detected = False
        for object_id, point in self.center_points.items():
            distance = math.hypot(cx - point[0], cy - point[1])
            if distance < self.distance_threshold:
                self.center_points[object_id] = (cx, cy)
                objects_bbs_ids.append([x, y, w, h, object_id])
                same_object_detected = True
                break
        if not same_object_detected:
            self.center_points[self.id_count] = (cx, cy)
            objects_bbs_ids.append([x, y, w, h, self.id_count])
            self.id_count += 1
    return objects_bbs_ids

def classify_trend(history):
    if len(history) < 12:
        return "資料累積中"
    recent   = history[-6:]
    previous = history[-12:-6]
    delta    = mean(recent) - mean(previous)
    if   delta >=  6: return "快速上升"
    elif delta >=  2: return "緩步上升"
    elif delta <= -6: return "快速下降"
    elif delta <= -2: return "緩步下降"
    else:            return "大致穩定"