import mmcv
[docs]def split_combined_polys(polys, poly_lens, polys_per_mask):
"""Split the combined 1-D polys into masks.
A mask is represented as a list of polys, and a poly is represented as
a 1-D array. In dataset, all masks are concatenated into a single 1-D
tensor. Here we need to split the tensor into original representations.
Args:
polys (list): a list (length = image num) of 1-D tensors
poly_lens (list): a list (length = image num) of poly length
polys_per_mask (list): a list (length = image num) of poly number
of each mask
Returns:
list: a list (length = image num) of list (length = mask num) of
list (length = poly num) of numpy array
"""
mask_polys_list = []
for img_id in range(len(polys)):
polys_single = polys[img_id]
polys_lens_single = poly_lens[img_id].tolist()
polys_per_mask_single = polys_per_mask[img_id].tolist()
split_polys = mmcv.slice_list(polys_single, polys_lens_single)
mask_polys = mmcv.slice_list(split_polys, polys_per_mask_single)
mask_polys_list.append(mask_polys)
return mask_polys_list