voc0712.py 文件源码

def detection_collate(batch):
    """Custom collate fn for dealing with batches of images that have a different
    number of associated object annotations (bounding boxes).

    Arguments:
        batch: (tuple) A tuple of tensor images and lists of annotations

    Return:
        A tuple containing:
            1) (tensor) batch of images stacked on their 0 dim
            2) (list of tensors) annotations for a given image are stacked on 0 dim
    """
    targets = []
    imgs = []
    for _, sample in enumerate(batch):
        for _, tup in enumerate(sample):
            #pdb.set_trace()
            if torch.is_tensor(tup):
                imgs.append(tup)
            elif isinstance(tup, type([])):
                annos = [torch.Tensor(a) for a in tup]
                #pdb.set_trace()
                targets.append(torch.stack(annos, 0))

    return (torch.stack(imgs, 0), targets)