def METHOD_NAME(self, bag, output, load):
    self.rects = {}
    self.sel_rect = None
    bc = BagCrawler(bag)
    self.rclk = False
    self.lclk = False
    topic = bc.image_topics[0]
    self.crawl_bu = bc.crawl(topic=topic)
    image = self.crawl_bu.next()
    self.image = self.bridge.imgmsg_to_cv2(image, "bgr8")
    self.crawl = bc.crawl(topic=topic)
    self.x, self.y = 0, 0
    self.rsel = True
    self.output = output
    w, h, r = self.image.shape
    self.button_pressed = False
    if load:
        self.collection = pickle.load(open(self.folder + "/" + output, "rb"))
    else:
        self.collection = ROI_Collection_Slow()
    self.collection.bag_to_rois[bag] = []
    self.mycoll = self.collection.bag_to_rois[bag]
    self.window_name = "segment"
    cv2.namedWindow(self.window_name)
    cv2.setMouseCallback(self.window_name, self.mouse_roi)
    self.last_rec = None
    def setw(x):
        if self.sel_rect is not None:
            r = self.rects[self.sel_rect]
            r[2] = x
    def seth(x):
        if self.sel_rect is not None:
            r = self.rects[self.sel_rect]
            r[3] = x
    cv2.createTrackbar("width", self.window_name, 0, w, setw)
    cv2.createTrackbar("height", self.window_name, 0, h, seth)