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# Copyright (c) OpenMMLab. All rights reserved.
from typing import List, Tuple
from torch import Tensor
from mmdet.models.task_modules import SamplingResult
from mmdet.registry import MODELS
from mmdet.structures import DetDataSample
from mmdet.structures.bbox import bbox2roi
from mmdet.utils import InstanceList
from ..losses.pisa_loss import carl_loss, isr_p
from ..utils import unpack_gt_instances
from .standard_roi_head import StandardRoIHead
@MODELS.register_module()
class PISARoIHead(StandardRoIHead):
r"""The RoI head for `Prime Sample Attention in Object Detection
<https://arxiv.org/abs/1904.04821>`_."""
def loss(self, x: Tuple[Tensor], rpn_results_list: InstanceList,
batch_data_samples: List[DetDataSample]) -> dict:
"""Perform forward propagation and loss calculation of the detection
roi on the features of the upstream network.
Args:
x (tuple[Tensor]): List of multi-level img features.
rpn_results_list (list[:obj:`InstanceData`]): List of region
proposals.
batch_data_samples (list[:obj:`DetDataSample`]): The batch
data samples. It usually includes information such
as `gt_instance` or `gt_panoptic_seg` or `gt_sem_seg`.
Returns:
dict[str, Tensor]: A dictionary of loss components
"""
assert len(rpn_results_list) == len(batch_data_samples)
outputs = unpack_gt_instances(batch_data_samples)
batch_gt_instances, batch_gt_instances_ignore, _ = outputs
# assign gts and sample proposals
num_imgs = len(batch_data_samples)
sampling_results = []
neg_label_weights = []
for i in range(num_imgs):
# rename rpn_results.bboxes to rpn_results.priors
rpn_results = rpn_results_list[i]
rpn_results.priors = rpn_results.pop('bboxes')
assign_result = self.bbox_assigner.assign(
rpn_results, batch_gt_instances[i],
batch_gt_instances_ignore[i])
sampling_result = self.bbox_sampler.sample(
assign_result,
rpn_results,
batch_gt_instances[i],
feats=[lvl_feat[i][None] for lvl_feat in x])
if isinstance(sampling_result, tuple):
sampling_result, neg_label_weight = sampling_result
sampling_results.append(sampling_result)
neg_label_weights.append(neg_label_weight)
losses = dict()
# bbox head forward and loss
if self.with_bbox:
bbox_results = self.bbox_loss(
x, sampling_results, neg_label_weights=neg_label_weights)
losses.update(bbox_results['loss_bbox'])
# mask head forward and loss
if self.with_mask:
mask_results = self.mask_loss(x, sampling_results,
bbox_results['bbox_feats'],
batch_gt_instances)
losses.update(mask_results['loss_mask'])
return losses
def bbox_loss(self,
x: Tuple[Tensor],
sampling_results: List[SamplingResult],
neg_label_weights: List[Tensor] = None) -> dict:
"""Perform forward propagation and loss calculation of the bbox head on
the features of the upstream network.
Args:
x (tuple[Tensor]): List of multi-level img features.
sampling_results (list["obj:`SamplingResult`]): Sampling results.
Returns:
dict[str, Tensor]: Usually returns a dictionary with keys:
- `cls_score` (Tensor): Classification scores.
- `bbox_pred` (Tensor): Box energies / deltas.
- `bbox_feats` (Tensor): Extract bbox RoI features.
- `loss_bbox` (dict): A dictionary of bbox loss components.
"""
rois = bbox2roi([res.priors for res in sampling_results])
bbox_results = self._bbox_forward(x, rois)
bbox_targets = self.bbox_head.get_targets(sampling_results,
self.train_cfg)
# neg_label_weights obtained by sampler is image-wise, mapping back to
# the corresponding location in label weights
if neg_label_weights[0] is not None:
label_weights = bbox_targets[1]
cur_num_rois = 0
for i in range(len(sampling_results)):
num_pos = sampling_results[i].pos_inds.size(0)
num_neg = sampling_results[i].neg_inds.size(0)
label_weights[cur_num_rois + num_pos:cur_num_rois + num_pos +
num_neg] = neg_label_weights[i]
cur_num_rois += num_pos + num_neg
cls_score = bbox_results['cls_score']
bbox_pred = bbox_results['bbox_pred']
# Apply ISR-P
isr_cfg = self.train_cfg.get('isr', None)
if isr_cfg is not None:
bbox_targets = isr_p(
cls_score,
bbox_pred,
bbox_targets,
rois,
sampling_results,
self.bbox_head.loss_cls,
self.bbox_head.bbox_coder,
**isr_cfg,
num_class=self.bbox_head.num_classes)
loss_bbox = self.bbox_head.loss(cls_score, bbox_pred, rois,
*bbox_targets)
# Add CARL Loss
carl_cfg = self.train_cfg.get('carl', None)
if carl_cfg is not None:
loss_carl = carl_loss(
cls_score,
bbox_targets[0],
bbox_pred,
bbox_targets[2],
self.bbox_head.loss_bbox,
**carl_cfg,
num_class=self.bbox_head.num_classes)
loss_bbox.update(loss_carl)
bbox_results.update(loss_bbox=loss_bbox)
return bbox_results