ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.

[cskate1997]

(venv) root@cc3180440f4b:/opendr/src/opendr/perception/panoptic_segmentation/efficient_ps/algorithm/EfficientPS# python tools/convert_cityscapes.py ./data_2/ ./data/cityscapes/
Loading Cityscapes from ./data_2/
Converting train ...
0%| | 0/2974 [00:00<?, ?it/s]
multiprocessing.pool.RemoteTraceback:
"""
Traceback (most recent call last):
File "/usr/lib/python3.8/multiprocessing/pool.py", line 125, in worker
result = (True, func(*args, **kwds))
File "/usr/lib/python3.8/multiprocessing/pool.py", line 48, in mapstar
return list(map(*args))
File "tools/convert_cityscapes.py", line 163, in call
coco_ann_i = pct.create_annotation_info(
File "/opendr/venv/lib/python3.8/site-packages/pycococreatortools/pycococreatortools.py", line 99, in create_annotation_info
segmentation = binary_mask_to_polygon(binary_mask, tolerance)
File "/opendr/venv/lib/python3.8/site-packages/pycococreatortools/pycococreatortools.py", line 48, in binary_mask_to_polygon
contours = np.subtract(contours, 1)
ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.
"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "tools/convert_cityscapes.py", line 198, in
main(parser.parse_args())
File "tools/convert_cityscapes.py", line 76, in main
for coco_img, coco_ann in tqdm.tqdm(pool.imap(worker, img_list, 8), total=total):
File "/opendr/venv/lib/python3.8/site-packages/tqdm/std.py", line 1166, in iter
for obj in iterable:
File "/usr/lib/python3.8/multiprocessing/pool.py", line 420, in
return (item for chunk in result for item in chunk)
File "/usr/lib/python3.8/multiprocessing/pool.py", line 868, in next
raise value
ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (2,) + inhomogeneous part.
(venv) root@cc3180440f4b:/opendr/src/opendr/perception/panoptic_segmentation/efficient_ps/algorithm/EfficientPS#

How can I solve the above error

I have installed pycococreator and pycocotools from https://github.com/waspinator/pycococreator

[KJYoung]

I don't know whether this is the valid solution, at least it worked.

CHANGE(pycococreatortools library's pycococreatortools.py binary_mask_to_polygon function(the error point):
contours = np.subtract(contours, 1)
to
contours = [ np.subtract(contour, 1) for contour in contours ]