Open YuNie24 opened 11 months ago
To avoid problems, the best is to create a script to remap your categories id once you have exported annotations.
Here is what a chatgpt tool like say to do (I don't have tested it, but it seem's ok):
To remap categories in a COCO annotation file using a Python script, you can follow these steps:
Install the required dependencies:
pip install pycocotools
Import the necessary libraries:
from pycocotools.coco import COCO
import json
Load the COCO annotation file:
annotation_file = 'path/to/annotation_file.json'
coco = COCO(annotation_file)
Define the mapping of old category IDs to new category IDs:
category_mapping = {
1: 10,
2: 20,
3: 30,
# add more mappings as needed
}
Create a new category list with remapped IDs:
new_categories = []
for old_cat_id, new_cat_id in category_mapping.items():
old_cat = coco.loadCats(old_cat_id)[0]
new_cat = old_cat.copy()
new_cat['id'] = new_cat_id
new_categories.append(new_cat)
Update the category list in the COCO annotation file:
coco.dataset['categories'] = new_categories
Update the category IDs in the annotation data:
for annotation in coco.dataset['annotations']:
old_cat_id = annotation['category_id']
new_cat_id = category_mapping.get(old_cat_id)
if new_cat_id:
annotation['category_id'] = new_cat_id
Save the updated annotation file:
remapped_annotation_file = 'path/to/remapped_annotation_file.json'
with open(remapped_annotation_file, 'w') as f:
json.dump(coco.dataset, f)
That's it! The resulting COCO annotation file with remapped categories will be saved as remapped_annotation_file.json. Make sure to replace 'path/to/annotation_file.json' and 'path/to/remapped_annotation_file.json' with the actual file paths.
Please note that this script assumes that the COCO annotation file follows the standard COCO format.
I have 5 class to bbox annotate.
But so far, category id is mapped automatically. On the web, I can edit category name, but it seems I can't change category id.
how can i fix category id on each class?