import mmcv
import torch
from mmdet.core import build_assigner, build_sampler
from mmdet.models.anchor_heads import AnchorHead
from mmdet.models.bbox_heads import BBoxHead
def test_anchor_head_loss():
"""
Tests anchor head loss when truth is empty and non-empty
"""
self = AnchorHead(num_classes=4, in_channels=1)
s = 256
img_metas = [{
'img_shape': (s, s, 3),
'scale_factor': 1,
'pad_shape': (s, s, 3)
}]
cfg = mmcv.Config({
'assigner': {
'type': 'MaxIoUAssigner',
'pos_iou_thr': 0.7,
'neg_iou_thr': 0.3,
'min_pos_iou': 0.3,
'ignore_iof_thr': -1
},
'sampler': {
'type': 'RandomSampler',
'num': 256,
'pos_fraction': 0.5,
'neg_pos_ub': -1,
'add_gt_as_proposals': False
},
'allowed_border': 0,
'pos_weight': -1,
'debug': False
})
# Anchor head expects a multiple levels of features per image
feat = [
torch.rand(1, 1, s // (2**(i + 2)), s // (2**(i + 2)))
for i in range(len(self.anchor_generators))
]
cls_scores, bbox_preds = 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, gt_bboxes, gt_labels,
img_metas, cfg, 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')
# 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, gt_bboxes, gt_labels,
img_metas, cfg, 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'
def test_bbox_head_loss():
"""
Tests bbox head loss when truth is empty and non-empty
"""
self = BBoxHead(in_channels=8, roi_feat_size=3)
num_imgs = 1
feat = torch.rand(1, 1, 3, 3)
# Dummy proposals
proposal_list = [
torch.Tensor([[23.6667, 23.8757, 228.6326, 153.8874]]),
]
target_cfg = mmcv.Config({'pos_weight': 1})
def _dummy_bbox_sampling(proposal_list, gt_bboxes, gt_labels):
"""
Create sample results that can be passed to BBoxHead.get_target
"""
assign_config = {
'type': 'MaxIoUAssigner',
'pos_iou_thr': 0.5,
'neg_iou_thr': 0.5,
'min_pos_iou': 0.5,
'ignore_iof_thr': -1
}
sampler_config = {
'type': 'RandomSampler',
'num': 512,
'pos_fraction': 0.25,
'neg_pos_ub': -1,
'add_gt_as_proposals': True
}
bbox_assigner = build_assigner(assign_config)
bbox_sampler = build_sampler(sampler_config)
gt_bboxes_ignore = [None for _ in range(num_imgs)]
sampling_results = []
for i in range(num_imgs):
assign_result = bbox_assigner.assign(proposal_list[i],
gt_bboxes[i],
gt_bboxes_ignore[i],
gt_labels[i])
sampling_result = bbox_sampler.sample(
assign_result,
proposal_list[i],
gt_bboxes[i],
gt_labels[i],
feats=feat)
sampling_results.append(sampling_result)
return sampling_results
# Test bbox loss when truth is empty
gt_bboxes = [torch.empty((0, 4))]
gt_labels = [torch.LongTensor([])]
sampling_results = _dummy_bbox_sampling(proposal_list, gt_bboxes,
gt_labels)
bbox_targets = self.get_target(sampling_results, gt_bboxes, gt_labels,
target_cfg)
labels, label_weights, bbox_targets, bbox_weights = bbox_targets
# Create dummy features "extracted" for each sampled bbox
num_sampled = sum(len(res.bboxes) for res in sampling_results)
dummy_feats = torch.rand(num_sampled, 8 * 3 * 3)
cls_scores, bbox_preds = self.forward(dummy_feats)
losses = self.loss(cls_scores, bbox_preds, labels, label_weights,
bbox_targets, bbox_weights)
assert losses.get('loss_cls', 0) > 0, 'cls-loss should be non-zero'
assert losses.get('loss_bbox', 0) == 0, 'empty gt loss should be zero'
# Test bbox loss when truth is non-empty
gt_bboxes = [
torch.Tensor([[23.6667, 23.8757, 238.6326, 151.8874]]),
]
gt_labels = [torch.LongTensor([2])]
sampling_results = _dummy_bbox_sampling(proposal_list, gt_bboxes,
gt_labels)
bbox_targets = self.get_target(sampling_results, gt_bboxes, gt_labels,
target_cfg)
labels, label_weights, bbox_targets, bbox_weights = bbox_targets
# Create dummy features "extracted" for each sampled bbox
num_sampled = sum(len(res.bboxes) for res in sampling_results)
dummy_feats = torch.rand(num_sampled, 8 * 3 * 3)
cls_scores, bbox_preds = self.forward(dummy_feats)
losses = self.loss(cls_scores, bbox_preds, labels, label_weights,
bbox_targets, bbox_weights)
assert losses.get('loss_cls', 0) > 0, 'cls-loss should be non-zero'
assert losses.get('loss_bbox', 0) > 0, 'box-loss should be non-zero'
def test_refine_boxes():
"""
Mirrors the doctest in
``mmdet.models.bbox_heads.bbox_head.BBoxHead.refine_boxes`` but checks for
multiple values of n_roi / n_img.
"""
self = BBoxHead(reg_class_agnostic=True)
test_settings = [
# Corner case: less rois than images
{
'n_roi': 2,
'n_img': 4,
'rng': 34285940
},
# Corner case: no images
{
'n_roi': 0,
'n_img': 0,
'rng': 52925222
},
# Corner cases: few images / rois
{
'n_roi': 1,
'n_img': 1,
'rng': 1200281
},
{
'n_roi': 2,
'n_img': 1,
'rng': 1200282
},
{
'n_roi': 2,
'n_img': 2,
'rng': 1200283
},
{
'n_roi': 1,
'n_img': 2,
'rng': 1200284
},
# Corner case: no rois few images
{
'n_roi': 0,
'n_img': 1,
'rng': 23955860
},
{
'n_roi': 0,
'n_img': 2,
'rng': 25830516
},
# Corner case: no rois many images
{
'n_roi': 0,
'n_img': 10,
'rng': 671346
},
{
'n_roi': 0,
'n_img': 20,
'rng': 699807
},
# Corner case: similar num rois and images
{
'n_roi': 20,
'n_img': 20,
'rng': 1200238
},
{
'n_roi': 10,
'n_img': 20,
'rng': 1200238
},
{
'n_roi': 5,
'n_img': 5,
'rng': 1200238
},
# ----------------------------------
# Common case: more rois than images
{
'n_roi': 100,
'n_img': 1,
'rng': 337156
},
{
'n_roi': 150,
'n_img': 2,
'rng': 275898
},
{
'n_roi': 500,
'n_img': 5,
'rng': 4903221
},
]
for demokw in test_settings:
try:
n_roi = demokw['n_roi']
n_img = demokw['n_img']
rng = demokw['rng']
print('Test refine_boxes case: {!r}'.format(demokw))
tup = _demodata_refine_boxes(n_roi, n_img, rng=rng)
rois, labels, bbox_preds, pos_is_gts, img_metas = tup
bboxes_list = self.refine_bboxes(rois, labels, bbox_preds,
pos_is_gts, img_metas)
assert len(bboxes_list) == n_img
assert sum(map(len, bboxes_list)) <= n_roi
assert all(b.shape[1] == 4 for b in bboxes_list)
except Exception:
print('Test failed with demokw={!r}'.format(demokw))
raise
def _demodata_refine_boxes(n_roi, n_img, rng=0):
"""
Create random test data for the
``mmdet.models.bbox_heads.bbox_head.BBoxHead.refine_boxes`` method
"""
import numpy as np
from mmdet.core.bbox.demodata import random_boxes
from mmdet.core.bbox.demodata import ensure_rng
try:
import kwarray
except ImportError:
import pytest
pytest.skip('kwarray is required for this test')
scale = 512
rng = ensure_rng(rng)
img_metas = [{'img_shape': (scale, scale)} for _ in range(n_img)]
# Create rois in the expected format
roi_boxes = random_boxes(n_roi, scale=scale, rng=rng)
if n_img == 0:
assert n_roi == 0, 'cannot have any rois if there are no images'
img_ids = torch.empty((0, ), dtype=torch.long)
roi_boxes = torch.empty((0, 4), dtype=torch.float32)
else:
img_ids = rng.randint(0, n_img, (n_roi, ))
img_ids = torch.from_numpy(img_ids)
rois = torch.cat([img_ids[:, None].float(), roi_boxes], dim=1)
# Create other args
labels = rng.randint(0, 2, (n_roi, ))
labels = torch.from_numpy(labels).long()
bbox_preds = random_boxes(n_roi, scale=scale, rng=rng)
# For each image, pretend random positive boxes are gts
is_label_pos = (labels.numpy() > 0).astype(np.int)
lbl_per_img = kwarray.group_items(is_label_pos, img_ids.numpy())
pos_per_img = [sum(lbl_per_img.get(gid, [])) for gid in range(n_img)]
# randomly generate with numpy then sort with torch
_pos_is_gts = [
rng.randint(0, 2, (npos, )).astype(np.uint8) for npos in pos_per_img
]
pos_is_gts = [
torch.from_numpy(p).sort(descending=True)[0] for p in _pos_is_gts
]
return rois, labels, bbox_preds, pos_is_gts, img_metas