# Copyright (c) Facebook, Inc. and its affiliates.
import logging
import os
from fvcore.common.timer import Timer
from detectron2.data import DatasetCatalog, MetadataCatalog
from detectron2.structures import BoxMode
from detectron2.utils.file_io import PathManager
from .builtin_meta import _get_coco_instances_meta
from .lvis_v0_5_categories import LVIS_CATEGORIES as LVIS_V0_5_CATEGORIES
from .lvis_v1_categories import LVIS_CATEGORIES as LVIS_V1_CATEGORIES
"""
This file contains functions to parse LVIS-format annotations into dicts in the
"Detectron2 format".
"""
logger = logging.getLogger(__name__)
__all__ = ["load_lvis_json", "register_lvis_instances", "get_lvis_instances_meta"]
[docs]def register_lvis_instances(name, metadata, json_file, image_root):
"""
Register a dataset in LVIS's json annotation format for instance detection and segmentation.
Args:
name (str): a name that identifies the dataset, e.g. "lvis_v0.5_train".
metadata (dict): extra metadata associated with this dataset. It can be an empty dict.
json_file (str): path to the json instance annotation file.
image_root (str or path-like): directory which contains all the images.
"""
DatasetCatalog.register(name, lambda: load_lvis_json(json_file, image_root, name))
MetadataCatalog.get(name).set(
json_file=json_file, image_root=image_root, evaluator_type="lvis", **metadata
)
[docs]def load_lvis_json(json_file, image_root, dataset_name=None, extra_annotation_keys=None):
"""
Load a json file in LVIS's annotation format.
Args:
json_file (str): full path to the LVIS json annotation file.
image_root (str): the directory where the images in this json file exists.
dataset_name (str): the name of the dataset (e.g., "lvis_v0.5_train").
If provided, this function will put "thing_classes" into the metadata
associated with this dataset.
extra_annotation_keys (list[str]): list of per-annotation keys that should also be
loaded into the dataset dict (besides "bbox", "bbox_mode", "category_id",
"segmentation"). The values for these keys will be returned as-is.
Returns:
list[dict]: a list of dicts in Detectron2 standard format. (See
`Using Custom Datasets </tutorials/datasets.html>`_ )
Notes:
1. This function does not read the image files.
The results do not have the "image" field.
"""
from lvis import LVIS
json_file = PathManager.get_local_path(json_file)
timer = Timer()
lvis_api = LVIS(json_file)
if timer.seconds() > 1:
logger.info("Loading {} takes {:.2f} seconds.".format(json_file, timer.seconds()))
if dataset_name is not None:
meta = get_lvis_instances_meta(dataset_name)
MetadataCatalog.get(dataset_name).set(**meta)
# sort indices for reproducible results
img_ids = sorted(lvis_api.imgs.keys())
# imgs is a list of dicts, each looks something like:
# {'license': 4,
# 'url': 'http://farm6.staticflickr.com/5454/9413846304_881d5e5c3b_z.jpg',
# 'file_name': 'COCO_val2014_000000001268.jpg',
# 'height': 427,
# 'width': 640,
# 'date_captured': '2013-11-17 05:57:24',
# 'id': 1268}
imgs = lvis_api.load_imgs(img_ids)
# anns is a list[list[dict]], where each dict is an annotation
# record for an object. The inner list enumerates the objects in an image
# and the outer list enumerates over images. Example of anns[0]:
# [{'segmentation': [[192.81,
# 247.09,
# ...
# 219.03,
# 249.06]],
# 'area': 1035.749,
# 'image_id': 1268,
# 'bbox': [192.81, 224.8, 74.73, 33.43],
# 'category_id': 16,
# 'id': 42986},
# ...]
anns = [lvis_api.img_ann_map[img_id] for img_id in img_ids]
# Sanity check that each annotation has a unique id
ann_ids = [ann["id"] for anns_per_image in anns for ann in anns_per_image]
assert len(set(ann_ids)) == len(ann_ids), "Annotation ids in '{}' are not unique".format(
json_file
)
imgs_anns = list(zip(imgs, anns))
logger.info("Loaded {} images in the LVIS format from {}".format(len(imgs_anns), json_file))
if extra_annotation_keys:
logger.info(
"The following extra annotation keys will be loaded: {} ".format(extra_annotation_keys)
)
else:
extra_annotation_keys = []
def get_file_name(img_root, img_dict):
# Determine the path including the split folder ("train2017", "val2017", "test2017") from
# the coco_url field. Example:
# 'coco_url': 'http://images.cocodataset.org/train2017/000000155379.jpg'
split_folder, file_name = img_dict["coco_url"].split("/")[-2:]
return os.path.join(img_root + split_folder, file_name)
dataset_dicts = []
for (img_dict, anno_dict_list) in imgs_anns:
record = {}
record["file_name"] = get_file_name(image_root, img_dict)
record["height"] = img_dict["height"]
record["width"] = img_dict["width"]
record["not_exhaustive_category_ids"] = img_dict.get("not_exhaustive_category_ids", [])
record["neg_category_ids"] = img_dict.get("neg_category_ids", [])
image_id = record["image_id"] = img_dict["id"]
objs = []
for anno in anno_dict_list:
# Check that the image_id in this annotation is the same as
# the image_id we're looking at.
# This fails only when the data parsing logic or the annotation file is buggy.
assert anno["image_id"] == image_id
obj = {"bbox": anno["bbox"], "bbox_mode": BoxMode.XYWH_ABS}
# LVIS data loader can be used to load COCO dataset categories. In this case `meta`
# variable will have a field with COCO-specific category mapping.
if dataset_name is not None and "thing_dataset_id_to_contiguous_id" in meta:
obj["category_id"] = meta["thing_dataset_id_to_contiguous_id"][anno["category_id"]]
else:
obj["category_id"] = anno["category_id"] - 1 # Convert 1-indexed to 0-indexed
segm = anno["segmentation"] # list[list[float]]
# filter out invalid polygons (< 3 points)
valid_segm = [poly for poly in segm if len(poly) % 2 == 0 and len(poly) >= 6]
assert len(segm) == len(
valid_segm
), "Annotation contains an invalid polygon with < 3 points"
assert len(segm) > 0
obj["segmentation"] = segm
for extra_ann_key in extra_annotation_keys:
obj[extra_ann_key] = anno[extra_ann_key]
objs.append(obj)
record["annotations"] = objs
dataset_dicts.append(record)
return dataset_dicts
def _get_lvis_instances_meta_v0_5():
assert len(LVIS_V0_5_CATEGORIES) == 1230
cat_ids = [k["id"] for k in LVIS_V0_5_CATEGORIES]
assert min(cat_ids) == 1 and max(cat_ids) == len(
cat_ids
), "Category ids are not in [1, #categories], as expected"
# Ensure that the category list is sorted by id
lvis_categories = sorted(LVIS_V0_5_CATEGORIES, key=lambda x: x["id"])
thing_classes = [k["synonyms"][0] for k in lvis_categories]
meta = {"thing_classes": thing_classes}
return meta
def _get_lvis_instances_meta_v1():
assert len(LVIS_V1_CATEGORIES) == 1203
cat_ids = [k["id"] for k in LVIS_V1_CATEGORIES]
assert min(cat_ids) == 1 and max(cat_ids) == len(
cat_ids
), "Category ids are not in [1, #categories], as expected"
# Ensure that the category list is sorted by id
lvis_categories = sorted(LVIS_V1_CATEGORIES, key=lambda x: x["id"])
thing_classes = [k["synonyms"][0] for k in lvis_categories]
meta = {"thing_classes": thing_classes}
return meta
if __name__ == "__main__":
"""
Test the LVIS json dataset loader.
Usage:
python -m detectron2.data.datasets.lvis \
path/to/json path/to/image_root dataset_name vis_limit
"""
import sys
import numpy as np
from detectron2.utils.logger import setup_logger
from PIL import Image
import detectron2.data.datasets # noqa # add pre-defined metadata
from detectron2.utils.visualizer import Visualizer
logger = setup_logger(name=__name__)
meta = MetadataCatalog.get(sys.argv[3])
dicts = load_lvis_json(sys.argv[1], sys.argv[2], sys.argv[3])
logger.info("Done loading {} samples.".format(len(dicts)))
dirname = "lvis-data-vis"
os.makedirs(dirname, exist_ok=True)
for d in dicts[: int(sys.argv[4])]:
img = np.array(Image.open(d["file_name"]))
visualizer = Visualizer(img, metadata=meta)
vis = visualizer.draw_dataset_dict(d)
fpath = os.path.join(dirname, os.path.basename(d["file_name"]))
vis.save(fpath)