def uniform_crop()

in datasets/video_transforms.py [0:0]


def uniform_crop(images, size, spatial_idx, boxes=None):
    """
    Perform uniform spatial sampling on the images and corresponding boxes.
    Args:
        images (tensor): images to perform uniform crop. The dimension is
            `num frames` x `channel` x `height` x `width`.
        size (int): size of height and weight to crop the images.
        spatial_idx (int): 0, 1, or 2 for left, center, and right crop if width
            is larger than height. Or 0, 1, or 2 for top, center, and bottom
            crop if height is larger than width.
        boxes (ndarray or None): optional. Corresponding boxes to images.
            Dimension is `num boxes` x 4.
    Returns:
        cropped (tensor): images with dimension of
            `num frames` x `channel` x `size` x `size`.
        cropped_boxes (ndarray or None): the cropped boxes with dimension of
            `num boxes` x 4.
    """
    assert spatial_idx in [0, 1, 2]
    height = images.shape[2]
    width = images.shape[3]

    y_offset = int(math.ceil((height - size) / 2))
    x_offset = int(math.ceil((width - size) / 2))

    if height > width:
        if spatial_idx == 0:
            y_offset = 0
        elif spatial_idx == 2:
            y_offset = height - size
    else:
        if spatial_idx == 0:
            x_offset = 0
        elif spatial_idx == 2:
            x_offset = width - size
    cropped = images[
        :, :, y_offset : y_offset + size, x_offset : x_offset + size
    ]

    cropped_boxes = (
        crop_boxes(boxes, x_offset, y_offset) if boxes is not None else None
    )

    return cropped, cropped_boxes