Issue in converting the instance segmentation mask encoding from bdd100k to coco

[sfarkya04]

Hello,

I am trying to convert the bdd100k instance segmentation using this command:
python3 -m bdd100k.label.to_coco -m ins_seg --only-mask -i ./bdd100k/labels/ins_seg/bitmasks/val -o ./ins_seg_val_cocofmt_v2.json

Also, tried this:
python3 -m bdd100k.label.to_coco -m ins_seg -i ./bdd100k/labels/ins_seg/polygons/ins_seg_val.json -o ./ins_seg_val_cocofmt_v3.json -mb ./bdd100k/labels/ins_seg/bitmasks/val

The conversion is successful in both cases and the annotation looks like this

** that's not how coco annotations are.

Now, if you see the segmentation field above there's string encoding of the masks. Now, I am unsure if that's expected or not.

Further, assuming it's correct, I tried to load the annotations using loader from DETR https://github.com/facebookresearch/detr/blob/091a817eca74b8b97e35e4531c1c39f89fbe38eb/datasets/coco.py#L36

The line I have mentioned above is supposed to do the conversion but I am getting an error from the pycocotools that it's not expecting a string in the mask.

So, I am unsure where the problem is? Is the conversion correct to coco then the loader should work?
Note: I tried to convert the detections and they worked fine.

Thank you for any help you can provide.

[thomasehuang]

Responded in BDD100K repo here: bdd100k/bdd100k#206 (comment). Closing this.