Hello. I’m trying to build a dataloader for the object detection task. I have the following class:
class TrafficLightsDataset(Dataset):
def __init__(self, df, transforms=None):
super().__init__()
# Image_ids will be the "Filename" here
self.image_ids = df.image_id.unique()
self.df = df
self.transforms = transforms
def __len__(self):
return self.image_ids.shape[0]
def __getitem__(self, index):
image_id = self.image_ids[index]
records = self.df[self.df.image_id == image_id]
# Reading Image
image = cv2.imread(image_id)
image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB).astype(np.float32)
image /= 255.0
# Bounding Boxes
boxes = records[['xmin','ymin','xmax','ymax']].values
boxes = torch.as_tensor(boxes.astype(int),dtype=torch.float32)
# Area of the bounding boxes
area = (boxes[:, 3] - boxes[:, 1]) * (boxes[:, 2] - boxes[:, 0])
area = torch.as_tensor(area, dtype=torch.float32)
# Labels of the object detected
labels = torch.as_tensor(records.label.values.astype(int), dtype=torch.int64)
iscrowd = torch.zeros_like(labels, dtype=torch.int64)
target = {}
target['boxes'] = boxes
target['labels'] = labels
target['image_id'] = torch.tensor([index])
target['area'] = area
target['iscrowd'] = iscrowd
if self.transforms:
sample = {
'image': image,
'bboxes': target['boxes'],
'labels': labels
}
sample = self.transforms(**sample)
image = sample['image']
target['boxes'] = torch.as_tensor(sample['bboxes'],dtype=torch.float32)
target['labels'] = torch.as_tensor(sample['labels'])
print(f'TARGET: {target}')
print(f'IMAGE: {image}')
return image, target
And initialize the dataloader as follows:
train_dataset = TrafficLightsDataset(train_df, transform)
train_dataLoader = DataLoader(
train_dataset,
batch_size=BATCH_SIZE,
shuffle=True,
num_workers=NUM_WORKERS,
collate_fn=utils.collate_fn
)
when I try to get a batch:
images, targets = next(iter(train_dataLoader))
I get the following error without explanation:
TypeError Traceback (most recent call last)
in <cell line: 1>()
----> 1 images, targets = next(iter(train_dataLoader))
TypeError: ‘bool’ object is not callable
I think it’s not about the class because I can print the result of the function “getitem”
print(f'TARGET: {target}')
print(f'IMAGE: {image}')
and I get the following (batch=2):
images, targets = next(iter(train_dataLoader))
The function result looks correct and I don’t understand where the error is. I ask for your help in finding the error.
