import random import torch.utils.data from lib.utils import TensorDict import numpy as np def no_processing(data): return data class TrackingSampler(torch.utils.data.Dataset): """ Class responsible for sampling frames from training sequences to form batches. The sampling is done in the following ways. First a dataset is selected at random. Next, a sequence is selected from that dataset. A base frame is then sampled randomly from the sequence. Next, a set of 'train frames' and 'test frames' are sampled from the sequence from the range [base_frame_id - max_gap, base_frame_id] and (base_frame_id, base_frame_id + max_gap] respectively. Only the frames in which the target is visible are sampled. If enough visible frames are not found, the 'max_gap' is increased gradually till enough frames are found. The sampled frames are then passed through the input 'processing' function for the necessary processing- """ def __init__(self, datasets, p_datasets, samples_per_epoch, max_gap, num_search_frames, num_template_frames=1, processing=no_processing, frame_sample_mode='causal', train_cls=False, pos_prob=0.5): """ args: datasets - List of datasets to be used for training p_datasets - List containing the probabilities by which each dataset will be sampled samples_per_epoch - Number of training samples per epoch max_gap - Maximum gap, in frame numbers, between the train frames and the test frames. num_search_frames - Number of search frames to sample. num_template_frames - Number of template frames to sample. processing - An instance of Processing class which performs the necessary processing of the data. frame_sample_mode - Either 'causal' or 'interval'. If 'causal', then the test frames are sampled in a causally, otherwise randomly within the interval. """ self.datasets = datasets self.train_cls = train_cls # whether we are training classification self.pos_prob = pos_prob # probability of sampling positive class when making classification # If p not provided, sample uniformly from all videos if p_datasets is None: p_datasets = [len(d) for d in self.datasets] # Normalize p_total = sum(p_datasets) self.p_datasets = [x / p_total for x in p_datasets] self.samples_per_epoch = samples_per_epoch self.max_gap = max_gap self.num_search_frames = num_search_frames self.num_template_frames = num_template_frames self.processing = processing self.frame_sample_mode = frame_sample_mode def __len__(self): return self.samples_per_epoch def _sample_visible_ids(self, visible, num_ids=1, min_id=None, max_id=None, allow_invisible=False, force_invisible=False): """ Samples num_ids frames between min_id and max_id for which target is visible args: visible - 1d Tensor indicating whether target is visible for each frame num_ids - number of frames to be samples min_id - Minimum allowed frame number max_id - Maximum allowed frame number returns: list - List of sampled frame numbers. None if not sufficient visible frames could be found. """ if num_ids == 0: return [] if min_id is None or min_id < 0: min_id = 0 if max_id is None or max_id > len(visible): max_id = len(visible) # get valid ids if force_invisible: valid_ids = [i for i in range(min_id, max_id) if not visible[i]] else: if allow_invisible: valid_ids = [i for i in range(min_id, max_id)] else: valid_ids = [i for i in range(min_id, max_id) if visible[i]] # No visible ids if len(valid_ids) == 0: return None return random.choices(valid_ids, k=num_ids) def __getitem__(self, index): if self.train_cls: return self.getitem_cls() else: return self.getitem() def getitem(self): """ returns: TensorDict - dict containing all the data blocks """ valid = False while not valid: # Select a dataset dataset = random.choices(self.datasets, self.p_datasets)[0] is_video_dataset = dataset.is_video_sequence() # sample a sequence from the given dataset seq_id, visible, seq_info_dict = self.sample_seq_from_dataset(dataset, is_video_dataset) if is_video_dataset: template_frame_ids = None search_frame_ids = None gap_increase = 0 if self.frame_sample_mode == 'causal': # Sample test and train frames in a causal manner, i.e. search_frame_ids > template_frame_ids while search_frame_ids is None: base_frame_id = self._sample_visible_ids(visible, num_ids=1, min_id=self.num_template_frames - 1, max_id=len(visible) - self.num_search_frames) prev_frame_ids = self._sample_visible_ids(visible, num_ids=self.num_template_frames - 1, min_id=base_frame_id[0] - self.max_gap - gap_increase, max_id=base_frame_id[0]) if prev_frame_ids is None: gap_increase += 5 continue template_frame_ids = base_frame_id + prev_frame_ids search_frame_ids = self._sample_visible_ids(visible, min_id=template_frame_ids[0] + 1, max_id=template_frame_ids[0] + self.max_gap + gap_increase, num_ids=self.num_search_frames) # Increase gap until a frame is found gap_increase += 5 elif self.frame_sample_mode == "trident" or self.frame_sample_mode == "trident_pro": template_frame_ids, search_frame_ids = self.get_frame_ids_trident(visible) elif self.frame_sample_mode == "stark": template_frame_ids, search_frame_ids = self.get_frame_ids_stark(visible, seq_info_dict["valid"]) else: raise ValueError("Illegal frame sample mode") else: # In case of image dataset, just repeat the image to generate synthetic video template_frame_ids = [1] * self.num_template_frames search_frame_ids = [1] * self.num_search_frames try: template_frames, template_anno, meta_obj_train = dataset.get_frames(seq_id, template_frame_ids, seq_info_dict) search_frames, search_anno, meta_obj_test = dataset.get_frames(seq_id, search_frame_ids, seq_info_dict) H, W, _ = template_frames[0].shape template_masks = template_anno['mask'] if 'mask' in template_anno else [torch.zeros((H, W))] * self.num_template_frames search_masks = search_anno['mask'] if 'mask' in search_anno else [torch.zeros((H, W))] * self.num_search_frames data = TensorDict({'template_images': template_frames, 'template_anno': template_anno['bbox'], 'template_masks': template_masks, 'search_images': search_frames, 'search_anno': search_anno['bbox'], 'search_masks': search_masks, 'dataset': dataset.get_name(), 'test_class': meta_obj_test.get('object_class_name')}) # make data augmentation data = self.processing(data) # check whether data is valid valid = data['valid'] except: valid = False return data def getitem_cls(self): # get data for classification """ args: index (int): Index (Ignored since we sample randomly) aux (bool): whether the current data is for auxiliary use (e.g. copy-and-paste) returns: TensorDict - dict containing all the data blocks """ valid = False label = None while not valid: # Select a dataset dataset = random.choices(self.datasets, self.p_datasets)[0] is_video_dataset = dataset.is_video_sequence() # sample a sequence from the given dataset seq_id, visible, seq_info_dict = self.sample_seq_from_dataset(dataset, is_video_dataset) # sample template and search frame ids if is_video_dataset: if self.frame_sample_mode in ["trident", "trident_pro"]: template_frame_ids, search_frame_ids = self.get_frame_ids_trident(visible) elif self.frame_sample_mode == "stark": template_frame_ids, search_frame_ids = self.get_frame_ids_stark(visible, seq_info_dict["valid"]) else: raise ValueError("illegal frame sample mode") else: # In case of image dataset, just repeat the image to generate synthetic video template_frame_ids = [1] * self.num_template_frames search_frame_ids = [1] * self.num_search_frames try: # "try" is used to handle trackingnet data failure # get images and bounding boxes (for templates) template_frames, template_anno, meta_obj_train = dataset.get_frames(seq_id, template_frame_ids, seq_info_dict) H, W, _ = template_frames[0].shape template_masks = template_anno['mask'] if 'mask' in template_anno else [torch.zeros( (H, W))] * self.num_template_frames # get images and bounding boxes (for searches) # positive samples if random.random() < self.pos_prob: label = torch.ones(1,) search_frames, search_anno, meta_obj_test = dataset.get_frames(seq_id, search_frame_ids, seq_info_dict) search_masks = search_anno['mask'] if 'mask' in search_anno else [torch.zeros( (H, W))] * self.num_search_frames # negative samples else: label = torch.zeros(1,) if is_video_dataset: search_frame_ids = self._sample_visible_ids(visible, num_ids=1, force_invisible=True) if search_frame_ids is None: search_frames, search_anno, meta_obj_test = self.get_one_search() else: search_frames, search_anno, meta_obj_test = dataset.get_frames(seq_id, search_frame_ids, seq_info_dict) search_anno["bbox"] = [self.get_center_box(H, W)] else: search_frames, search_anno, meta_obj_test = self.get_one_search() H, W, _ = search_frames[0].shape search_masks = search_anno['mask'] if 'mask' in search_anno else [torch.zeros( (H, W))] * self.num_search_frames data = TensorDict({'template_images': template_frames, 'template_anno': template_anno['bbox'], 'template_masks': template_masks, 'search_images': search_frames, 'search_anno': search_anno['bbox'], 'search_masks': search_masks, 'dataset': dataset.get_name(), 'test_class': meta_obj_test.get('object_class_name')}) # make data augmentation data = self.processing(data) # add classification label data["label"] = label # check whether data is valid valid = data['valid'] except: valid = False return data def get_center_box(self, H, W, ratio=1/8): cx, cy, w, h = W/2, H/2, W * ratio, H * ratio return torch.tensor([int(cx-w/2), int(cy-h/2), int(w), int(h)]) def sample_seq_from_dataset(self, dataset, is_video_dataset): # Sample a sequence with enough visible frames enough_visible_frames = False while not enough_visible_frames: # Sample a sequence seq_id = random.randint(0, dataset.get_num_sequences() - 1) # Sample frames seq_info_dict = dataset.get_sequence_info(seq_id) visible = seq_info_dict['visible'] enough_visible_frames = visible.type(torch.int64).sum().item() > 2 * ( self.num_search_frames + self.num_template_frames) and len(visible) >= 20 enough_visible_frames = enough_visible_frames or not is_video_dataset return seq_id, visible, seq_info_dict def get_one_search(self): # Select a dataset dataset = random.choices(self.datasets, self.p_datasets)[0] is_video_dataset = dataset.is_video_sequence() # sample a sequence seq_id, visible, seq_info_dict = self.sample_seq_from_dataset(dataset, is_video_dataset) # sample a frame if is_video_dataset: if self.frame_sample_mode == "stark": search_frame_ids = self._sample_visible_ids(seq_info_dict["valid"], num_ids=1) else: search_frame_ids = self._sample_visible_ids(visible, num_ids=1, allow_invisible=True) else: search_frame_ids = [1] # get the image, bounding box and other info search_frames, search_anno, meta_obj_test = dataset.get_frames(seq_id, search_frame_ids, seq_info_dict) return search_frames, search_anno, meta_obj_test def get_frame_ids_trident(self, visible): # get template and search ids in a 'trident' manner template_frame_ids_extra = [] while None in template_frame_ids_extra or len(template_frame_ids_extra) == 0: template_frame_ids_extra = [] # first randomly sample two frames from a video template_frame_id1 = self._sample_visible_ids(visible, num_ids=1) # the initial template id search_frame_ids = self._sample_visible_ids(visible, num_ids=1) # the search region id # get the dynamic template id for max_gap in self.max_gap: if template_frame_id1[0] >= search_frame_ids[0]: min_id, max_id = search_frame_ids[0], search_frame_ids[0] + max_gap else: min_id, max_id = search_frame_ids[0] - max_gap, search_frame_ids[0] if self.frame_sample_mode == "trident_pro": f_id = self._sample_visible_ids(visible, num_ids=1, min_id=min_id, max_id=max_id, allow_invisible=True) else: f_id = self._sample_visible_ids(visible, num_ids=1, min_id=min_id, max_id=max_id) if f_id is None: template_frame_ids_extra += [None] else: template_frame_ids_extra += f_id template_frame_ids = template_frame_id1 + template_frame_ids_extra return template_frame_ids, search_frame_ids def get_frame_ids_stark(self, visible, valid): # get template and search ids in a 'stark' manner template_frame_ids_extra = [] while None in template_frame_ids_extra or len(template_frame_ids_extra) == 0: template_frame_ids_extra = [] # first randomly sample two frames from a video template_frame_id1 = self._sample_visible_ids(visible, num_ids=1) # the initial template id search_frame_ids = self._sample_visible_ids(visible, num_ids=1) # the search region id # get the dynamic template id for max_gap in self.max_gap: if template_frame_id1[0] >= search_frame_ids[0]: min_id, max_id = search_frame_ids[0], search_frame_ids[0] + max_gap else: min_id, max_id = search_frame_ids[0] - max_gap, search_frame_ids[0] """we require the frame to be valid but not necessary visible""" f_id = self._sample_visible_ids(valid, num_ids=1, min_id=min_id, max_id=max_id) if f_id is None: template_frame_ids_extra += [None] else: template_frame_ids_extra += f_id template_frame_ids = template_frame_id1 + template_frame_ids_extra return template_frame_ids, search_frame_ids