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2026-07-13 13:35:51 +08:00

169 lines
5.4 KiB
Python

"""Pascal VOC object detection dataset."""
from __future__ import absolute_import, division
import json
import logging
import os
import pickle
import warnings
from collections import Counter
import dgl
import mxnet as mx
import numpy as np
from gluoncv.data.base import VisionDataset
from gluoncv.data.transforms.presets.rcnn import (
FasterRCNNDefaultTrainTransform,
FasterRCNNDefaultValTransform,
)
class VGRelation(VisionDataset):
def __init__(
self,
root=os.path.join("~", ".mxnet", "datasets", "visualgenome"),
split="train",
):
super(VGRelation, self).__init__(root)
self._root = os.path.expanduser(root)
self._img_path = os.path.join(self._root, "VG_100K", "{}")
if split == "train":
self._dict_path = os.path.join(
self._root, "rel_annotations_train.json"
)
elif split == "val":
self._dict_path = os.path.join(
self._root, "rel_annotations_val.json"
)
else:
raise NotImplementedError
with open(self._dict_path) as f:
tmp = f.read()
self._dict = json.loads(tmp)
self._predicates_path = os.path.join(self._root, "predicates.json")
with open(self._predicates_path, "r") as f:
tmp = f.read()
self.rel_classes = json.loads(tmp)
self.num_rel_classes = len(self.rel_classes) + 1
self._objects_path = os.path.join(self._root, "objects.json")
with open(self._objects_path, "r") as f:
tmp = f.read()
self.obj_classes = json.loads(tmp)
self.num_obj_classes = len(self.obj_classes)
if split == "val":
self.img_transform = FasterRCNNDefaultValTransform(
short=600, max_size=1000
)
else:
self.img_transform = FasterRCNNDefaultTrainTransform(
short=600, max_size=1000
)
self.split = split
def __len__(self):
return len(self._dict)
def _hash_bbox(self, object):
num_list = [object["category"]] + object["bbox"]
return "_".join([str(num) for num in num_list])
def __getitem__(self, idx):
img_id = list(self._dict)[idx]
img_path = self._img_path.format(img_id)
img = mx.image.imread(img_path)
item = self._dict[img_id]
n_edges = len(item)
# edge to node ids
sub_node_hash = []
ob_node_hash = []
for i, it in enumerate(item):
sub_node_hash.append(self._hash_bbox(it["subject"]))
ob_node_hash.append(self._hash_bbox(it["object"]))
node_set = sorted(list(set(sub_node_hash + ob_node_hash)))
n_nodes = len(node_set)
node_to_id = {}
for i, node in enumerate(node_set):
node_to_id[node] = i
sub_id = []
ob_id = []
for i in range(n_edges):
sub_id.append(node_to_id[sub_node_hash[i]])
ob_id.append(node_to_id[ob_node_hash[i]])
# node features
bbox = mx.nd.zeros((n_nodes, 4))
node_class_ids = mx.nd.zeros((n_nodes, 1))
node_visited = [False for i in range(n_nodes)]
for i, it in enumerate(item):
if not node_visited[sub_id[i]]:
ind = sub_id[i]
sub = it["subject"]
node_class_ids[ind] = sub["category"]
# y1y2x1x2 to x1y1x2y2
bbox[ind, 0] = sub["bbox"][2]
bbox[ind, 1] = sub["bbox"][0]
bbox[ind, 2] = sub["bbox"][3]
bbox[ind, 3] = sub["bbox"][1]
node_visited[ind] = True
if not node_visited[ob_id[i]]:
ind = ob_id[i]
ob = it["object"]
node_class_ids[ind] = ob["category"]
# y1y2x1x2 to x1y1x2y2
bbox[ind, 0] = ob["bbox"][2]
bbox[ind, 1] = ob["bbox"][0]
bbox[ind, 2] = ob["bbox"][3]
bbox[ind, 3] = ob["bbox"][1]
node_visited[ind] = True
eta = 0.1
node_class_vec = node_class_ids[:, 0].one_hot(
self.num_obj_classes,
on_value=1 - eta + eta / self.num_obj_classes,
off_value=eta / self.num_obj_classes,
)
# augmentation
if self.split == "val":
img, bbox, _ = self.img_transform(img, bbox)
else:
img, bbox = self.img_transform(img, bbox)
# build the graph
g = dgl.DGLGraph()
g.add_nodes(n_nodes)
adjmat = np.zeros((n_nodes, n_nodes))
predicate = []
for i, it in enumerate(item):
adjmat[sub_id[i], ob_id[i]] = 1
predicate.append(it["predicate"])
predicate = mx.nd.array(predicate).expand_dims(1)
g.add_edges(sub_id, ob_id, {"rel_class": mx.nd.array(predicate) + 1})
empty_edge_list = []
for i in range(n_nodes):
for j in range(n_nodes):
if i != j and adjmat[i, j] == 0:
empty_edge_list.append((i, j))
if len(empty_edge_list) > 0:
src, dst = tuple(zip(*empty_edge_list))
g.add_edges(
src, dst, {"rel_class": mx.nd.zeros((len(empty_edge_list), 1))}
)
# assign features
g.ndata["bbox"] = bbox
g.ndata["node_class"] = node_class_ids
g.ndata["node_class_vec"] = node_class_vec
return g, img