Skip to content
Branch: master
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
178 lines (146 sloc) 5.92 KB
Module for converting JSON exports to MS COCO format.
import datetime as dt
import json
import logging
from typing import Any, Dict
from PIL import Image
import requests
from shapely import wkt
from shapely.geometry import Polygon
from labelbox.exceptions import UnknownFormatError
LOGGER = logging.getLogger(__name__)
def from_json(labeled_data, coco_output, label_format='WKT'):
"Writes labelbox JSON export into MS COCO format."
# read labelbox JSON output
with open(labeled_data, 'r') as file_handle:
label_data = json.loads(
# setup COCO dataset container and info
coco = make_coco_metadata(label_data[0]['Project Name'], label_data[0]['Created By'],)
for data in label_data:
# Download and get image name
add_label(coco, data['ID'], data['Labeled Data'], data['Label'], label_format)
except requests.exceptions.MissingSchema as exc:
except requests.exceptions.ConnectionError:
LOGGER.warning('Failed to fetch image from %s, skipping', data['Labeled Data'])
with open(coco_output, 'w+') as file_handle:
def make_coco_metadata(project_name: str, created_by: str) -> Dict[str, Any]:
"""Initializes COCO export data structure.
project_name: name of the project
created_by: email of the project creator
The COCO export represented as a dictionary.
return {
'info': {
'version': None,
'description': project_name,
'contributor': created_by,
'url': '',
'images': [],
'annotations': [],
'licenses': [],
'categories': []
def add_label(
coco: Dict[str, Any], label_id: str, image_url: str,
labels: Dict[str, Any], label_format: str):
"""Incrementally updates COCO export data structure with a new label.
coco: The current COCO export, will be incrementally updated by this method.
label_id: ID for the instance to write
image_url: URL to download image file from
labels: Labelbox formatted labels to use for generating annotation
label_format: Format of the labeled data. Valid options are: "WKT" and
"XY", default is "WKT".
The updated COCO export represented as a dictionary.
image = {
"id": label_id,
"file_name": image_url,
"license": None,
"flickr_url": image_url,
"coco_url": image_url,
"date_captured": None,
response = requests.get(image_url, stream=True, timeout=1.0)
response.raw.decode_content = True
image['width'], image['height'] =
# remove classification labels (Skip, etc...)
if not callable(getattr(labels, 'keys', None)):
# convert label to COCO Polygon format
for category_name, label_data in labels.items():
# check if label category exists in 'categories' field
category_id = [c['id']
for c in coco['categories']
if c['supercategory'] == category_name][0]
except IndexError:
category_id = len(coco['categories']) + 1
category = {
'supercategory': category_name,
'id': category_id,
'name': category_name
polygons = _get_polygons(label_format, label_data)
_append_polygons_as_annotations(coco, image, category_id, polygons)
def _append_polygons_as_annotations(coco, image, category_id, polygons):
"Adds `polygons` as annotations in the `coco` export"
for polygon in polygons:
segmentation = []
for x_val, y_val in polygon.exterior.coords:
segmentation.extend([x_val, y_val])
annotation = {
"id": len(coco['annotations']) + 1,
"image_id": image['id'],
"category_id": category_id,
"segmentation": [segmentation],
"area": polygon.area, # float
"bbox": [polygon.bounds[0], polygon.bounds[1],
polygon.bounds[2] - polygon.bounds[0],
polygon.bounds[3] - polygon.bounds[1]],
"iscrowd": 0
def _get_polygons(label_format, label_data):
"Converts segmentation `label: String!` into polygons"
if label_format == 'WKT':
if isinstance(label_data, list): # V3
polygons = map(lambda x: wkt.loads(x['geometry']), label_data)
else: # V2
polygons = wkt.loads(label_data)
elif label_format == 'XY':
polygons = []
for xy_list in label_data:
if 'geometry' in xy_list: # V3
xy_list = xy_list['geometry']
# V2 and V3
if not isinstance(xy_list, list):
LOGGER.warning('Could not get an point list to construct polygon, skipping')
else: # V2, or non-list
if not isinstance(xy_list, list) or not xy_list or 'x' not in xy_list[0]:
# skip non xy lists
LOGGER.warning('Could not get an point list to construct polygon, skipping')
if len(xy_list) > 2: # need at least 3 points to make a polygon
polygons.append(Polygon(map(lambda p: (p['x'], p['y']), xy_list)))
exc = UnknownFormatError(label_format=label_format)
raise exc
return polygons
You can’t perform that action at this time.