def fcos_config():
"""FCOS Head Config."""
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 = FCOSHead(num_classes=4, in_channels=1, test_cfg=test_cfg)
model.requires_grad_(False)
return model
def test_fcos_head_loss():
"""Tests fcos 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)
}]
train_cfg = mmcv.Config(
dict(
assigner=dict(
type='MaxIoUAssigner',
pos_iou_thr=0.5,
neg_iou_thr=0.4,
min_pos_iou=0,
ignore_iof_thr=-1),
allowed_border=-1,
pos_weight=-1,
debug=False))
# since Focal Loss is not supported on CPU
self = FCOSHead(
num_classes=4,
in_channels=1,
train_cfg=train_cfg,
loss_cls=dict(
type='CrossEntropyLoss', use_sigmoid=True, loss_weight=1.0))
feat = [
torch.rand(1, 1, s // feat_size, s // feat_size)
for feat_size in [4, 8, 16, 32, 64]
]
cls_scores, bbox_preds, centerness = self.forward(feat)
# Test that empty ground truth encourages the network to predict background
gt_bboxes = [torch.empty((0, 4))]
gt_labels = [torch.LongTensor([])]
gt_bboxes_ignore = None
empty_gt_losses = self.loss(cls_scores, bbox_preds, centerness, 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 = empty_gt_losses['loss_cls']
empty_box_loss = 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')
# 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]]),
]
gt_labels = [torch.LongTensor([2])]
one_gt_losses = self.loss(cls_scores, bbox_preds, centerness, gt_bboxes,
gt_labels, img_metas, gt_bboxes_ignore)
onegt_cls_loss = one_gt_losses['loss_cls']
onegt_box_loss = 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'