Function dense_patch_slices

monai/data/utils.py:164–204

Enumerate all slices defining ND patches of size `patch_size` from an `image_size` input image. Args: image_size: dimensions of image to iterate over patch_size: size of patches to generate slices scan_interval: dense patch sampling interval return_slice: wh

(
    image_size: Sequence[int], patch_size: Sequence[int], scan_interval: Sequence[int], return_slice: bool = True
)

def dense_patch_slices(
    image_size: Sequence[int], patch_size: Sequence[int], scan_interval: Sequence[int], return_slice: bool = True
) -> list[tuple[slice, ...]]:
    """
    Enumerate all slices defining ND patches of size `patch_size` from an `image_size` input image.

    Args:
        image_size: dimensions of image to iterate over
        patch_size: size of patches to generate slices
        scan_interval: dense patch sampling interval
        return_slice: whether to return a list of slices (or tuples of indices), defaults to True

    Returns:
        a list of slice objects defining each patch

    """
    num_spatial_dims = len(image_size)
    patch_size = get_valid_patch_size(image_size, patch_size)
    scan_interval = ensure_tuple_size(scan_interval, num_spatial_dims)

    scan_num = []
    for i in range(num_spatial_dims):
        if scan_interval[i] == 0:
            scan_num.append(1)
        else:
            num = int(math.ceil(float(image_size[i]) / scan_interval[i]))
            scan_dim = first(d for d in range(num) if d * scan_interval[i] + patch_size[i] >= image_size[i])
            scan_num.append(scan_dim + 1 if scan_dim is not None else 1)

    starts = []
    for dim in range(num_spatial_dims):
        dim_starts = []
        for idx in range(scan_num[dim]):
            start_idx = idx * scan_interval[dim]
            start_idx -= max(start_idx + patch_size[dim] - image_size[dim], 0)
            dim_starts.append(start_idx)
        starts.append(dim_starts)
    out = np.asarray([x.flatten() for x in np.meshgrid(*starts, indexing="ij")]).T
    if return_slice:
        return [tuple(slice(s, s + patch_size[d]) for d, s in enumerate(x)) for x in out]
    return [tuple((s, s + patch_size[d]) for d, s in enumerate(x)) for x in out]  # type: ignore


def iter_patch_position(