def instances_to_coco_json(instances, img_id):
"""
Dump an "Instances" object to a COCO-format json that's used for evaluation.
Args:
instances (Instances):
img_id (int): the image id
Returns:
list[dict]: list of json annotations in COCO format.
"""
num_instance = len(instances)
if num_instance == 0:
return []
boxes = instances.pred_boxes.tensor.numpy()
boxes = BoxMode.convert(boxes, BoxMode.XYXY_ABS, BoxMode.XYWH_ABS)
boxes = boxes.tolist()
scores = instances.scores.tolist()
classes = instances.pred_classes.tolist()
has_mask = instances.has("pred_masks")
if has_mask:
# use RLE to encode the masks, because they are too large and takes memory
# since this evaluator stores outputs of the entire dataset
rles = [
mask_util.encode(
np.array(mask[:, :, None], order="F", dtype="uint8"))[0]
for mask in instances.pred_masks
]
for rle in rles:
# "counts" is an array encoded by mask_util as a byte-stream. Python3's
# json writer which always produces strings cannot serialize a bytestream
# unless you decode it. Thankfully, utf-8 works out (which is also what
# the pycocotools/_mask.pyx does).
rle["counts"] = rle["counts"].decode("utf-8")
has_keypoints = instances.has("pred_keypoints")
if has_keypoints:
keypoints = instances.pred_keypoints
results = []
for k in range(num_instance):
result = {
"image_id": img_id,
"category_id": classes[k],
"bbox": boxes[k],
"score": scores[k],
}
if has_mask:
result["segmentation"] = rles[k]
if has_keypoints:
# In COCO annotations,
# keypoints coordinates are pixel indices.
# However our predictions are floating point coordinates.
# Therefore we subtract 0.5 to be consistent with the annotation format.
# This is the inverse of data loading logic in `datasets/coco.py`.
keypoints[k][:, :2] -= 0.5
result["keypoints"] = keypoints[k].flatten().tolist()
results.append(result)
return results
def load_proposals_into_dataset(dataset_dicts, proposal_file):
r"""
Load precomputed object proposals into the dataset.
The proposal file should be a pickled dict with the following keys:
- "ids": list[int] or list[str], the image ids
- "boxes": list[np.ndarray], each is an Nx4 array of boxes corresponding to the image id
- "objectness_logits": list[np.ndarray], each is an N sized array of objectness scores
corresponding to the boxes.
- "bbox_mode": the BoxMode of the boxes array. Defaults to ``BoxMode.XYXY_ABS``.
Args:
dataset_dicts (list[dict]): annotations in dl_lib Dataset format.
proposal_file (str): file path of pre-computed proposals, in pkl format.
Returns:
list[dict]: the same format as dataset_dicts, but added proposal field.
"""
logger = logging.getLogger(__name__)
logger.info("Loading proposals from: {}".format(proposal_file))
with PathManager.open(proposal_file, "rb") as f:
proposals = pickle.load(f, encoding="latin1")
# Rename the key names in D1 proposal files
rename_keys = {"indexes": "ids", "scores": "objectness_logits"}
for key in rename_keys:
if key in proposals:
proposals[rename_keys[key]] = proposals.pop(key)
# Fetch the indexes of all proposals that are in the dataset
# Convert image_id to str since they could be int.
img_ids = set({str(record["image_id"]) for record in dataset_dicts})
id_to_index = {
str(id): i
for i, id in enumerate(proposals["ids"]) if str(id) in img_ids
}
# Assuming default bbox_mode of precomputed proposals are 'XYXY_ABS'
bbox_mode = BoxMode(proposals["bbox_mode"]
) if "bbox_mode" in proposals else BoxMode.XYXY_ABS
for record in dataset_dicts:
# Get the index of the proposal
i = id_to_index[str(record["image_id"])]
boxes = proposals["boxes"][i]
objectness_logits = proposals["objectness_logits"][i]
# Sort the proposals in descending order of the scores
inds = objectness_logits.argsort()[::-1]
record["proposal_boxes"] = boxes[inds]
record["proposal_objectness_logits"] = objectness_logits[inds]
record["proposal_bbox_mode"] = bbox_mode
return dataset_dicts
def transform_instance_annotations(annotation,
transforms,
image_size,
*,
keypoint_hflip_indices=None):
"""
Apply transforms to box, segmentation and keypoints annotations of a single instance.
It will use `transforms.apply_box` for the box, and
`transforms.apply_coords` for segmentation polygons & keypoints.
If you need anything more specially designed for each data structure,
you'll need to implement your own version of this function or the transforms.
Args:
annotation (dict): dict of instance annotations for a single instance.
It will be modified in-place.
transforms (TransformList):
image_size (tuple): the height, width of the transformed image
keypoint_hflip_indices (ndarray[int]): see `create_keypoint_hflip_indices`.
Returns:
dict:
the same input dict with fields "bbox", "segmentation", "keypoints"
transformed according to `transforms`.
The "bbox_mode" field will be set to XYXY_ABS.
"""
bbox = BoxMode.convert(annotation["bbox"], annotation["bbox_mode"],
BoxMode.XYXY_ABS)
# Note that bbox is 1d (per-instance bounding box)
annotation["bbox"] = transforms.apply_box([bbox])[0]
annotation["bbox_mode"] = BoxMode.XYXY_ABS
if "segmentation" in annotation:
# each instance contains 1 or more polygons
polygons = [
np.asarray(p).reshape(-1, 2) for p in annotation["segmentation"]
]
annotation["segmentation"] = [
p.reshape(-1) for p in transforms.apply_polygons(polygons)
]
if "keypoints" in annotation:
keypoints = transform_keypoint_annotations(annotation["keypoints"],
transforms, image_size,
keypoint_hflip_indices)
annotation["keypoints"] = keypoints
return annotation
def draw_dataset_dict(self, dic):
"""
Draw annotations/segmentaions in Detectron2 Dataset format.
Args:
dic (dict): annotation/segmentation data of one image, in Detectron2 Dataset format.
Returns:
output (VisImage): image object with visualizations.
"""
annos = dic.get("annotations", None)
if annos:
if "segmentation" in annos[0]:
masks = [x["segmentation"] for x in annos]
else:
masks = None
if "keypoints" in annos[0]:
keypts = [x["keypoints"] for x in annos]
keypts = np.array(keypts).reshape(len(annos), -1, 3)
else:
keypts = None
boxes = [
BoxMode.convert(x["bbox"], x["bbox_mode"], BoxMode.XYXY_ABS)
for x in annos
]
labels = [x["category_id"] for x in annos]
names = self.metadata.get("thing_classes", None)
if names:
labels = [names[i] for i in labels]
labels = [
"{}".format(i) + ("|crowd" if a.get("iscrowd", 0) else "")
for i, a in zip(labels, annos)
]
self.overlay_instances(labels=labels,
boxes=boxes,
masks=masks,
keypoints=keypts)
sem_seg = dic.get("sem_seg", None)
if sem_seg is None and "sem_seg_file_name" in dic:
sem_seg = cv2.imread(dic["sem_seg_file_name"],
cv2.IMREAD_GRAYSCALE)
if sem_seg is not None:
self.draw_sem_seg(sem_seg, area_threshold=0, alpha=0.5)
return self.output
def annotations_to_instances(annos, image_size, mask_format="polygon"):
"""
Create an :class:`Instances` object used by the models,
from instance annotations in the dataset dict.
Args:
annos (list[dict]): a list of instance annotations in one image, each
element for one instance.
image_size (tuple): height, width
Returns:
Instances:
It will contain fields "gt_boxes", "gt_classes",
"gt_masks", "gt_keypoints", if they can be obtained from `annos`.
This is the format that builtin models expect.
"""
boxes = [
BoxMode.convert(obj["bbox"], obj["bbox_mode"], BoxMode.XYXY_ABS)
for obj in annos
]
target = Instances(image_size)
boxes = target.gt_boxes = Boxes(boxes)
boxes.clip(image_size)
classes = [obj["category_id"] for obj in annos]
classes = torch.tensor(classes, dtype=torch.int64)
target.gt_classes = classes
if len(annos) and "segmentation" in annos[0]:
polygons = [obj["segmentation"] for obj in annos]
if mask_format == "polygon":
masks = PolygonMasks(polygons)
else:
assert mask_format == "bitmask", mask_format
masks = BitMasks.from_polygon_masks(polygons, *image_size)
target.gt_masks = masks
if len(annos) and "keypoints" in annos[0]:
kpts = [obj.get("keypoints", []) for obj in annos]
target.gt_keypoints = Keypoints(kpts)
return target
def transform_proposals(dataset_dict, image_shape, transforms,
min_box_side_len, proposal_topk):
"""
Apply transformations to the proposals in dataset_dict, if any.
Args:
dataset_dict (dict): a dict read from the dataset, possibly
contains fields "proposal_boxes", "proposal_objectness_logits", "proposal_bbox_mode"
image_shape (tuple): height, width
transforms (TransformList):
min_box_side_len (int): keep proposals with at least this size
proposal_topk (int): only keep top-K scoring proposals
The input dict is modified in-place, with abovementioned keys removed. A new
key "proposals" will be added. Its value is an `Instances`
object which contains the transformed proposals in its field
"proposal_boxes" and "objectness_logits".
"""
if "proposal_boxes" in dataset_dict:
# Transform proposal boxes
boxes = transforms.apply_box(
BoxMode.convert(
dataset_dict.pop("proposal_boxes"),
dataset_dict.pop("proposal_bbox_mode"),
BoxMode.XYXY_ABS,
))
boxes = Boxes(boxes)
objectness_logits = torch.as_tensor(
dataset_dict.pop("proposal_objectness_logits").astype("float32"))
boxes.clip(image_shape)
keep = boxes.nonempty(threshold=min_box_side_len)
boxes = boxes[keep]
objectness_logits = objectness_logits[keep]
proposals = Instances(image_shape)
proposals.proposal_boxes = boxes[:proposal_topk]
proposals.objectness_logits = objectness_logits[:proposal_topk]
dataset_dict["proposals"] = proposals
def gen_crop_transform_with_instance(crop_size, image_size, instance):
"""
Generate a CropTransform so that the cropping region contains
the center of the given instance.
Args:
crop_size (tuple): h, w in pixels
image_size (tuple): h, w
instance (dict): an annotation dict of one instance, in dl_lib's
dataset format.
"""
crop_size = np.asarray(crop_size, dtype=np.int32)
bbox = BoxMode.convert(instance["bbox"], instance["bbox_mode"],
BoxMode.XYXY_ABS)
center_yx = (bbox[1] + bbox[3]) * 0.5, (bbox[0] + bbox[2]) * 0.5
min_yx = np.maximum(np.floor(center_yx).astype(np.int32) - crop_size, 0)
max_yx = np.maximum(np.asarray(image_size, dtype=np.int32) - crop_size, 0)
max_yx = np.minimum(max_yx, np.ceil(center_yx).astype(np.int32))
y0 = np.random.randint(min_yx[0], max_yx[0] + 1)
x0 = np.random.randint(min_yx[1], max_yx[1] + 1)
return T.CropTransform(x0, y0, crop_size[1], crop_size[0])
def convert_to_coco_dict(dataset_name):
"""
Convert a dataset in detectron2's standard format into COCO json format
Generic dataset description can be found here:
https://detectron2.readthedocs.io/tutorials/datasets.html#register-a-dataset
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 detectron2's standard format
Returns:
coco_dict: serializable dict in COCO json format
"""
dataset_dicts = DatasetCatalog.get(dataset_name)
categories = [{
"id": id,
"name": name
} for id, name in enumerate(
MetadataCatalog.get(dataset_name).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"] = 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 Detectron2.",
}
coco_dict = {
"info": info,
"images": coco_images,
"annotations": coco_annotations,
"categories": categories,
"licenses": None,
}
return coco_dict
def _evaluate_box_proposals(dataset_predictions,
coco_api,
thresholds=None,
area="all",
limit=None):
"""
Evaluate detection proposal recall metrics. This function is a much
faster alternative to the official COCO API recall evaluation code. However,
it produces slightly different results.
"""
# Record max overlap value for each gt box
# Return vector of overlap values
areas = {
"all": 0,
"small": 1,
"medium": 2,
"large": 3,
"96-128": 4,
"128-256": 5,
"256-512": 6,
"512-inf": 7,
}
area_ranges = [
[0**2, 1e5**2], # all
[0**2, 32**2], # small
[32**2, 96**2], # medium
[96**2, 1e5**2], # large
[96**2, 128**2], # 96-128
[128**2, 256**2], # 128-256
[256**2, 512**2], # 256-512
[512**2, 1e5**2],
] # 512-inf
assert area in areas, "Unknown area range: {}".format(area)
area_range = area_ranges[areas[area]]
gt_overlaps = []
num_pos = 0
for prediction_dict in dataset_predictions:
predictions = prediction_dict["proposals"]
# sort predictions in descending order
# TODO maybe remove this and make it explicit in the documentation
inds = predictions.objectness_logits.sort(descending=True)[1]
predictions = predictions[inds]
ann_ids = coco_api.getAnnIds(imgIds=prediction_dict["image_id"])
anno = coco_api.loadAnns(ann_ids)
gt_boxes = [
BoxMode.convert(obj["bbox"], BoxMode.XYWH_ABS, BoxMode.XYXY_ABS)
for obj in anno if obj["iscrowd"] == 0
]
gt_boxes = torch.as_tensor(gt_boxes).reshape(
-1, 4) # guard against no boxes
gt_boxes = Boxes(gt_boxes)
gt_areas = torch.as_tensor(
[obj["area"] for obj in anno if obj["iscrowd"] == 0])
if len(gt_boxes) == 0 or len(predictions) == 0:
continue
valid_gt_inds = (gt_areas >= area_range[0]) & (gt_areas <=
area_range[1])
gt_boxes = gt_boxes[valid_gt_inds]
num_pos += len(gt_boxes)
if len(gt_boxes) == 0:
continue
if limit is not None and len(predictions) > limit:
predictions = predictions[:limit]
overlaps = pairwise_iou(predictions.proposal_boxes, gt_boxes)
_gt_overlaps = torch.zeros(len(gt_boxes))
for j in range(min(len(predictions), len(gt_boxes))):
# find which proposal box maximally covers each gt box
# and get the iou amount of coverage for each gt box
max_overlaps, argmax_overlaps = overlaps.max(dim=0)
# find which gt box is 'best' covered (i.e. 'best' = most iou)
gt_ovr, gt_ind = max_overlaps.max(dim=0)
assert gt_ovr >= 0
# find the proposal box that covers the best covered gt box
box_ind = argmax_overlaps[gt_ind]
# record the iou coverage of this gt box
_gt_overlaps[j] = overlaps[box_ind, gt_ind]
assert _gt_overlaps[j] == gt_ovr
# mark the proposal box and the gt box as used
overlaps[box_ind, :] = -1
overlaps[:, gt_ind] = -1
# append recorded iou coverage level
gt_overlaps.append(_gt_overlaps)
gt_overlaps = torch.cat(gt_overlaps, dim=0)
gt_overlaps, _ = torch.sort(gt_overlaps)
if thresholds is None:
step = 0.05
thresholds = torch.arange(0.5, 0.95 + 1e-5, step, dtype=torch.float32)
recalls = torch.zeros_like(thresholds)
# compute recall for each iou threshold
for i, t in enumerate(thresholds):
recalls[i] = (gt_overlaps >= t).float().sum() / float(num_pos)
# ar = 2 * np.trapz(recalls, thresholds)
ar = recalls.mean()
return {
"ar": ar,
"recalls": recalls,
"thresholds": thresholds,
"gt_overlaps": gt_overlaps,
"num_pos": num_pos,
}
def transform_instance_annotations(annotation,
transforms,
image_size,
*,
keypoint_hflip_indices=None,
dot_number):
"""
Apply transforms to box, segmentation and keypoints annotations of a single instance.
It will use `transforms.apply_box` for the box, and
`transforms.apply_coords` for segmentation polygons & keypoints.
If you need anything more specially designed for each data structure,
you'll need to implement your own version of this function or the transforms.
Args:
annotation (dict): dict of instance annotations for a single instance.
It will be modified in-place.
transforms (TransformList):
image_size (tuple): the height, width of the transformed image
keypoint_hflip_indices (ndarray[int]): see `create_keypoint_hflip_indices`.
Returns:
dict:
the same input dict with fields "bbox", "segmentation", "keypoints"
transformed according to `transforms`.
The "bbox_mode" field will be set to XYXY_ABS.
"""
bbox = BoxMode.convert(annotation["bbox"], annotation["bbox_mode"],
BoxMode.XYXY_ABS)
# Note that bbox is 1d (per-instance bounding box)
annotation["bbox"] = transforms.apply_box([bbox])[0]
annotation["bbox_mode"] = BoxMode.XYXY_ABS
if "segmentation" in annotation:
# each instance contains 1 or more polygons
dot_counts = [len(i) // 2 for i in annotation["segmentation"]]
dot_gap = [
i // dot_number if i >= dot_number else 1 for i in dot_counts
]
x = [
i[0::(2 * j)] for i, j in zip(annotation["segmentation"], dot_gap)
]
y = [
i[1::(2 * j)] for i, j in zip(annotation["segmentation"], dot_gap)
]
# x = [[i[:dot_number]] if len(i) >= dot_number else [i + [-1] * (dot_number - len(i))] for i in x]
# y = [[i[:dot_number]] if len(i) >= dot_number else [i + [-1] * (dot_number - len(i))] for i in y]
x = [[i[:dot_number]] for i in x]
y = [[i[:dot_number]] for i in y]
polygons = [
np.concatenate([np.asarray(i), np.asarray(j)], axis=0).T
for i, j in zip(x, y)
]
# polygons = [np.asarray(p).reshape(-1, 2) for p in annotation["segmentation"]]
annotation["segmentation"] = [
p.reshape(-1) for p in transforms.apply_polygons(polygons)
]
if "keypoints" in annotation:
keypoints = transform_keypoint_annotations(annotation["keypoints"],
transforms, image_size,
keypoint_hflip_indices)
annotation["keypoints"] = keypoints
return annotation