def test_polygon_area(self):
# Draw polygon boxes
for d in [5.0, 10.0, 1000.0]:
polygon = PolygonMasks([[[0, 0, 0, d, d, d, d, 0]]])
area = polygon.area()[0]
target = d**2
self.assertEqual(area, target)
# Draw polygon triangles
for d in [5.0, 10.0, 1000.0]:
polygon = PolygonMasks([[[0, 0, 0, d, d, d]]])
area = polygon.area()[0]
target = d**2 / 2
self.assertEqual(area, target)
def convert_to_coco_dict(dataset_name, dataset_dicts, metadata):
"""
Convert a dataset in cvpods's standard format into COCO json format
COCO data format description can be found here:
http://cocodataset.org/#format-data
Args:
dataset_name:
name of the source dataset
must be registered in DatastCatalog and in cvpods's standard format
Returns:
coco_dict: serializable dict in COCO json format
"""
if dataset_name not in [
"citypersons_train", "citypersons_val", "crowdhuman_train",
"crowdhuman_val", "coco_2017_train", "coco_2017_val",
"widerface_2019_train", "widerface_2019_val"
]:
raise NotImplementedError(
"Dataset name '{}' not supported".format(dataset_name))
# unmap the category mapping ids for COCO
if hasattr(metadata, "thing_dataset_id_to_contiguous_id"):
reverse_id_mapping = {
v: k
for k, v in metadata.thing_dataset_id_to_contiguous_id.items()
}
def reverse_id_mapper(contiguous_id):
return reverse_id_mapping[contiguous_id] # noqa
else:
def reverse_id_mapper(contiguous_id):
return contiguous_id # noqa
categories = [{
"id": reverse_id_mapper(id),
"name": name
} for id, name in enumerate(metadata.thing_classes)]
logger.info("Converting dataset dicts into COCO format")
coco_images = []
coco_annotations = []
for image_id, image_dict in enumerate(dataset_dicts):
coco_image = {
"id": image_dict.get("image_id", image_id),
"width": image_dict["width"],
"height": image_dict["height"],
"file_name": image_dict["file_name"],
}
coco_images.append(coco_image)
anns_per_image = image_dict["annotations"]
for annotation in anns_per_image:
# create a new dict with only COCO fields
coco_annotation = {}
# COCO requirement: XYWH box format
bbox = annotation["bbox"]
bbox_mode = annotation["bbox_mode"]
bbox = BoxMode.convert(bbox, bbox_mode, BoxMode.XYWH_ABS)
# COCO requirement: instance area
if "segmentation" in annotation:
# Computing areas for instances by counting the pixels
segmentation = annotation["segmentation"]
# TODO: check segmentation type: RLE, BinaryMask or Polygon
polygons = PolygonMasks([segmentation])
area = polygons.area()[0].item()
else:
# Computing areas using bounding boxes
bbox_xy = BoxMode.convert(bbox, BoxMode.XYWH_ABS,
BoxMode.XYXY_ABS)
area = Boxes([bbox_xy]).area()[0].item()
if "keypoints" in annotation:
keypoints = annotation["keypoints"] # list[int]
for idx, v in enumerate(keypoints):
if idx % 3 != 2:
# COCO's segmentation coordinates are floating points in [0, H or W],
# but keypoint coordinates are integers in [0, H-1 or W-1]
# For COCO format consistency we substract 0.5
# https://github.com/facebookresearch/detectron2/pull/175#issuecomment-551202163
keypoints[idx] = v - 0.5
if "num_keypoints" in annotation:
num_keypoints = annotation["num_keypoints"]
else:
num_keypoints = sum(kp > 0 for kp in keypoints[2::3])
# COCO requirement:
# linking annotations to images
# "id" field must start with 1
coco_annotation["id"] = len(coco_annotations) + 1
coco_annotation["image_id"] = coco_image["id"]
coco_annotation["bbox"] = [round(float(x), 3) for x in bbox]
coco_annotation["area"] = area
coco_annotation["category_id"] = reverse_id_mapper(
annotation["category_id"])
coco_annotation["iscrowd"] = annotation.get("iscrowd", 0)
# Add optional fields
if "keypoints" in annotation:
coco_annotation["keypoints"] = keypoints
coco_annotation["num_keypoints"] = num_keypoints
if "segmentation" in annotation:
coco_annotation["segmentation"] = annotation["segmentation"]
coco_annotations.append(coco_annotation)
logger.info(
"Conversion finished, "
f"num images: {len(coco_images)}, num annotations: {len(coco_annotations)}"
)
info = {
"date_created": str(datetime.datetime.now()),
"description": "Automatically generated COCO json file for cvpods.",
}
coco_dict = {
"info": info,
"images": coco_images,
"annotations": coco_annotations,
"categories": categories,
"licenses": None,
}
return coco_dict