def fsaf_config():
"""FSAF Head Config."""
cfg = dict(anchor_generator=dict(type='AnchorGenerator',
octave_base_scale=1,
scales_per_octave=1,
ratios=[1.0],
strides=[8, 16, 32, 64, 128]))
test_cfg = mmcv.Config(
dict(deploy_nms_pre=0,
min_bbox_size=0,
score_thr=0.05,
nms=dict(type='nms', iou_threshold=0.5),
max_per_img=100))
model = FSAFHead(num_classes=4, in_channels=1, test_cfg=test_cfg, **cfg)
model.requires_grad_(False)
return model
def test_fsaf_head_loss():
"""Tests anchor head loss when truth is empty and non-empty."""
s = 256
img_metas = [{
'img_shape': (s, s, 3),
'scale_factor': 1,
'pad_shape': (s, s, 3)
}]
cfg = dict(reg_decoded_bbox=True,
anchor_generator=dict(type='AnchorGenerator',
octave_base_scale=1,
scales_per_octave=1,
ratios=[1.0],
strides=[8, 16, 32, 64, 128]),
bbox_coder=dict(type='TBLRBBoxCoder', normalizer=4.0),
loss_cls=dict(type='FocalLoss',
use_sigmoid=True,
gamma=2.0,
alpha=0.25,
loss_weight=1.0,
reduction='none'),
loss_bbox=dict(type='IoULoss',
eps=1e-6,
loss_weight=1.0,
reduction='none'))
train_cfg = mmcv.Config(
dict(assigner=dict(type='CenterRegionAssigner',
pos_scale=0.2,
neg_scale=0.2,
min_pos_iof=0.01),
allowed_border=-1,
pos_weight=-1,
debug=False))
head = FSAFHead(num_classes=4, in_channels=1, train_cfg=train_cfg, **cfg)
if torch.cuda.is_available():
head.cuda()
# FSAF head expects a multiple levels of features per image
feat = [
torch.rand(1, 1, s // (2**(i + 2)), s // (2**(i + 2))).cuda()
for i in range(len(head.anchor_generator.strides))
]
cls_scores, bbox_preds = head.forward(feat)
gt_bboxes_ignore = None
# When truth is non-empty then both cls and box loss should be nonzero
# for random inputs
gt_bboxes = [
torch.Tensor([[23.6667, 23.8757, 238.6326, 151.8874]]).cuda(),
]
gt_labels = [torch.LongTensor([2]).cuda()]
one_gt_losses = head.loss(cls_scores, bbox_preds, gt_bboxes, gt_labels,
img_metas, gt_bboxes_ignore)
onegt_cls_loss = sum(one_gt_losses['loss_cls'])
onegt_box_loss = sum(one_gt_losses['loss_bbox'])
assert onegt_cls_loss.item() > 0, 'cls loss should be non-zero'
assert onegt_box_loss.item() > 0, 'box loss should be non-zero'
# Test that empty ground truth encourages the network to predict bkg
gt_bboxes = [torch.empty((0, 4)).cuda()]
gt_labels = [torch.LongTensor([]).cuda()]
empty_gt_losses = head.loss(cls_scores, bbox_preds, gt_bboxes,
gt_labels, img_metas, gt_bboxes_ignore)
# When there is no truth, the cls loss should be nonzero but there
# should be no box loss.
empty_cls_loss = sum(empty_gt_losses['loss_cls'])
empty_box_loss = sum(empty_gt_losses['loss_bbox'])
assert empty_cls_loss.item() > 0, 'cls loss should be non-zero'
assert empty_box_loss.item() == 0, (
'there should be no box loss when there are no true boxes')
