Source code for mmdet.models.roi_heads.cascade_roi_head
# Copyright (c) OpenMMLab. All rights reserved.
import numpy as np
import torch
import torch.nn as nn
from mmcv.runner import ModuleList
from mmdet.core import (bbox2result, bbox2roi, bbox_mapping, build_assigner,
build_sampler, merge_aug_bboxes, merge_aug_masks,
multiclass_nms)
from ..builder import HEADS, build_head, build_roi_extractor
from .base_roi_head import BaseRoIHead
from .test_mixins import BBoxTestMixin, MaskTestMixin
[docs]@HEADS.register_module()
class CascadeRoIHead(BaseRoIHead, BBoxTestMixin, MaskTestMixin):
"""Cascade roi head including one bbox head and one mask head.
https://arxiv.org/abs/1712.00726
"""
def __init__(self,
num_stages,
stage_loss_weights,
bbox_roi_extractor=None,
bbox_head=None,
mask_roi_extractor=None,
mask_head=None,
shared_head=None,
train_cfg=None,
test_cfg=None,
pretrained=None,
init_cfg=None):
assert bbox_roi_extractor is not None
assert bbox_head is not None
assert shared_head is None, \
'Shared head is not supported in Cascade RCNN anymore'
self.num_stages = num_stages
self.stage_loss_weights = stage_loss_weights
super(CascadeRoIHead, self).__init__(
bbox_roi_extractor=bbox_roi_extractor,
bbox_head=bbox_head,
mask_roi_extractor=mask_roi_extractor,
mask_head=mask_head,
shared_head=shared_head,
train_cfg=train_cfg,
test_cfg=test_cfg,
pretrained=pretrained,
init_cfg=init_cfg)
[docs] def init_bbox_head(self, bbox_roi_extractor, bbox_head):
"""Initialize box head and box roi extractor.
Args:
bbox_roi_extractor (dict): Config of box roi extractor.
bbox_head (dict): Config of box in box head.
"""
self.bbox_roi_extractor = ModuleList()
self.bbox_head = ModuleList()
if not isinstance(bbox_roi_extractor, list):
bbox_roi_extractor = [
bbox_roi_extractor for _ in range(self.num_stages)
]
if not isinstance(bbox_head, list):
bbox_head = [bbox_head for _ in range(self.num_stages)]
assert len(bbox_roi_extractor) == len(bbox_head) == self.num_stages
for roi_extractor, head in zip(bbox_roi_extractor, bbox_head):
self.bbox_roi_extractor.append(build_roi_extractor(roi_extractor))
self.bbox_head.append(build_head(head))
[docs] def init_mask_head(self, mask_roi_extractor, mask_head):
"""Initialize mask head and mask roi extractor.
Args:
mask_roi_extractor (dict): Config of mask roi extractor.
mask_head (dict): Config of mask in mask head.
"""
self.mask_head = nn.ModuleList()
if not isinstance(mask_head, list):
mask_head = [mask_head for _ in range(self.num_stages)]
assert len(mask_head) == self.num_stages
for head in mask_head:
self.mask_head.append(build_head(head))
if mask_roi_extractor is not None:
self.share_roi_extractor = False
self.mask_roi_extractor = ModuleList()
if not isinstance(mask_roi_extractor, list):
mask_roi_extractor = [
mask_roi_extractor for _ in range(self.num_stages)
]
assert len(mask_roi_extractor) == self.num_stages
for roi_extractor in mask_roi_extractor:
self.mask_roi_extractor.append(
build_roi_extractor(roi_extractor))
else:
self.share_roi_extractor = True
self.mask_roi_extractor = self.bbox_roi_extractor
[docs] def init_assigner_sampler(self):
"""Initialize assigner and sampler for each stage."""
self.bbox_assigner = []
self.bbox_sampler = []
if self.train_cfg is not None:
for idx, rcnn_train_cfg in enumerate(self.train_cfg):
self.bbox_assigner.append(
build_assigner(rcnn_train_cfg.assigner))
self.current_stage = idx
self.bbox_sampler.append(
build_sampler(rcnn_train_cfg.sampler, context=self))
[docs] def forward_dummy(self, x, proposals):
"""Dummy forward function."""
# bbox head
outs = ()
rois = bbox2roi([proposals])
if self.with_bbox:
for i in range(self.num_stages):
bbox_results = self._bbox_forward(i, x, rois)
outs = outs + (bbox_results['cls_score'],
bbox_results['bbox_pred'])
# mask heads
if self.with_mask:
mask_rois = rois[:100]
for i in range(self.num_stages):
mask_results = self._mask_forward(i, x, mask_rois)
outs = outs + (mask_results['mask_pred'], )
return outs
def _bbox_forward(self, stage, x, rois):
"""Box head forward function used in both training and testing."""
bbox_roi_extractor = self.bbox_roi_extractor[stage]
bbox_head = self.bbox_head[stage]
bbox_feats = bbox_roi_extractor(x[:bbox_roi_extractor.num_inputs],
rois)
# do not support caffe_c4 model anymore
cls_score, bbox_pred = bbox_head(bbox_feats)
bbox_results = dict(
cls_score=cls_score, bbox_pred=bbox_pred, bbox_feats=bbox_feats)
return bbox_results
def _bbox_forward_train(self, stage, x, sampling_results, gt_bboxes,
gt_labels, rcnn_train_cfg):
"""Run forward function and calculate loss for box head in training."""
rois = bbox2roi([res.bboxes for res in sampling_results])
bbox_results = self._bbox_forward(stage, x, rois)
bbox_targets = self.bbox_head[stage].get_targets(
sampling_results, gt_bboxes, gt_labels, rcnn_train_cfg)
loss_bbox = self.bbox_head[stage].loss(bbox_results['cls_score'],
bbox_results['bbox_pred'], rois,
*bbox_targets)
bbox_results.update(
loss_bbox=loss_bbox, rois=rois, bbox_targets=bbox_targets)
return bbox_results
def _mask_forward(self, stage, x, rois):
"""Mask head forward function used in both training and testing."""
mask_roi_extractor = self.mask_roi_extractor[stage]
mask_head = self.mask_head[stage]
mask_feats = mask_roi_extractor(x[:mask_roi_extractor.num_inputs],
rois)
# do not support caffe_c4 model anymore
mask_pred = mask_head(mask_feats)
mask_results = dict(mask_pred=mask_pred)
return mask_results
def _mask_forward_train(self,
stage,
x,
sampling_results,
gt_masks,
rcnn_train_cfg,
bbox_feats=None):
"""Run forward function and calculate loss for mask head in
training."""
pos_rois = bbox2roi([res.pos_bboxes for res in sampling_results])
mask_results = self._mask_forward(stage, x, pos_rois)
mask_targets = self.mask_head[stage].get_targets(
sampling_results, gt_masks, rcnn_train_cfg)
pos_labels = torch.cat([res.pos_gt_labels for res in sampling_results])
loss_mask = self.mask_head[stage].loss(mask_results['mask_pred'],
mask_targets, pos_labels)
mask_results.update(loss_mask=loss_mask)
return mask_results
[docs] def forward_train(self,
x,
img_metas,
proposal_list,
gt_bboxes,
gt_labels,
gt_bboxes_ignore=None,
gt_masks=None):
"""
Args:
x (list[Tensor]): list of multi-level img features.
img_metas (list[dict]): list of image info dict where each dict
has: 'img_shape', 'scale_factor', 'flip', and may also contain
'filename', 'ori_shape', 'pad_shape', and 'img_norm_cfg'.
For details on the values of these keys see
`mmdet/datasets/pipelines/formatting.py:Collect`.
proposals (list[Tensors]): list of region proposals.
gt_bboxes (list[Tensor]): Ground truth bboxes for each image with
shape (num_gts, 4) in [tl_x, tl_y, br_x, br_y] format.
gt_labels (list[Tensor]): class indices corresponding to each box
gt_bboxes_ignore (None | list[Tensor]): specify which bounding
boxes can be ignored when computing the loss.
gt_masks (None | Tensor) : true segmentation masks for each box
used if the architecture supports a segmentation task.
Returns:
dict[str, Tensor]: a dictionary of loss components
"""
losses = dict()
for i in range(self.num_stages):
self.current_stage = i
rcnn_train_cfg = self.train_cfg[i]
lw = self.stage_loss_weights[i]
# assign gts and sample proposals
sampling_results = []
if self.with_bbox or self.with_mask:
bbox_assigner = self.bbox_assigner[i]
bbox_sampler = self.bbox_sampler[i]
num_imgs = len(img_metas)
if gt_bboxes_ignore is None:
gt_bboxes_ignore = [None for _ in range(num_imgs)]
for j in range(num_imgs):
assign_result = bbox_assigner.assign(
proposal_list[j], gt_bboxes[j], gt_bboxes_ignore[j],
gt_labels[j])
sampling_result = bbox_sampler.sample(
assign_result,
proposal_list[j],
gt_bboxes[j],
gt_labels[j],
feats=[lvl_feat[j][None] for lvl_feat in x])
sampling_results.append(sampling_result)
# bbox head forward and loss
bbox_results = self._bbox_forward_train(i, x, sampling_results,
gt_bboxes, gt_labels,
rcnn_train_cfg)
for name, value in bbox_results['loss_bbox'].items():
losses[f's{i}.{name}'] = (
value * lw if 'loss' in name else value)
# mask head forward and loss
if self.with_mask:
mask_results = self._mask_forward_train(
i, x, sampling_results, gt_masks, rcnn_train_cfg,
bbox_results['bbox_feats'])
for name, value in mask_results['loss_mask'].items():
losses[f's{i}.{name}'] = (
value * lw if 'loss' in name else value)
# refine bboxes
if i < self.num_stages - 1:
pos_is_gts = [res.pos_is_gt for res in sampling_results]
# bbox_targets is a tuple
roi_labels = bbox_results['bbox_targets'][0]
with torch.no_grad():
cls_score = bbox_results['cls_score']
if self.bbox_head[i].custom_activation:
cls_score = self.bbox_head[i].loss_cls.get_activation(
cls_score)
# Empty proposal.
if cls_score.numel() == 0:
break
roi_labels = torch.where(
roi_labels == self.bbox_head[i].num_classes,
cls_score[:, :-1].argmax(1), roi_labels)
proposal_list = self.bbox_head[i].refine_bboxes(
bbox_results['rois'], roi_labels,
bbox_results['bbox_pred'], pos_is_gts, img_metas)
return losses
[docs] def simple_test(self, x, proposal_list, img_metas, rescale=False):
"""Test without augmentation.
Args:
x (tuple[Tensor]): Features from upstream network. Each
has shape (batch_size, c, h, w).
proposal_list (list(Tensor)): Proposals from rpn head.
Each has shape (num_proposals, 5), last dimension
5 represent (x1, y1, x2, y2, score).
img_metas (list[dict]): Meta information of images.
rescale (bool): Whether to rescale the results to
the original image. Default: True.
Returns:
list[list[np.ndarray]] or list[tuple]: When no mask branch,
it is bbox results of each image and classes with type
`list[list[np.ndarray]]`. The outer list
corresponds to each image. The inner list
corresponds to each class. When the model has mask branch,
it contains bbox results and mask results.
The outer list corresponds to each image, and first element
of tuple is bbox results, second element is mask results.
"""
assert self.with_bbox, 'Bbox head must be implemented.'
num_imgs = len(proposal_list)
img_shapes = tuple(meta['img_shape'] for meta in img_metas)
ori_shapes = tuple(meta['ori_shape'] for meta in img_metas)
scale_factors = tuple(meta['scale_factor'] for meta in img_metas)
# "ms" in variable names means multi-stage
ms_bbox_result = {}
ms_segm_result = {}
ms_scores = []
rcnn_test_cfg = self.test_cfg
rois = bbox2roi(proposal_list)
if rois.shape[0] == 0:
# There is no proposal in the whole batch
bbox_results = [[
np.zeros((0, 5), dtype=np.float32)
for _ in range(self.bbox_head[-1].num_classes)
]] * num_imgs
if self.with_mask:
mask_classes = self.mask_head[-1].num_classes
segm_results = [[[] for _ in range(mask_classes)]
for _ in range(num_imgs)]
results = list(zip(bbox_results, segm_results))
else:
results = bbox_results
return results
for i in range(self.num_stages):
bbox_results = self._bbox_forward(i, x, rois)
# split batch bbox prediction back to each image
cls_score = bbox_results['cls_score']
bbox_pred = bbox_results['bbox_pred']
num_proposals_per_img = tuple(
len(proposals) for proposals in proposal_list)
rois = rois.split(num_proposals_per_img, 0)
cls_score = cls_score.split(num_proposals_per_img, 0)
if isinstance(bbox_pred, torch.Tensor):
bbox_pred = bbox_pred.split(num_proposals_per_img, 0)
else:
bbox_pred = self.bbox_head[i].bbox_pred_split(
bbox_pred, num_proposals_per_img)
ms_scores.append(cls_score)
if i < self.num_stages - 1:
if self.bbox_head[i].custom_activation:
cls_score = [
self.bbox_head[i].loss_cls.get_activation(s)
for s in cls_score
]
refine_rois_list = []
for j in range(num_imgs):
if rois[j].shape[0] > 0:
bbox_label = cls_score[j][:, :-1].argmax(dim=1)
refined_rois = self.bbox_head[i].regress_by_class(
rois[j], bbox_label, bbox_pred[j], img_metas[j])
refine_rois_list.append(refined_rois)
rois = torch.cat(refine_rois_list)
# average scores of each image by stages
cls_score = [
sum([score[i] for score in ms_scores]) / float(len(ms_scores))
for i in range(num_imgs)
]
# apply bbox post-processing to each image individually
det_bboxes = []
det_labels = []
for i in range(num_imgs):
det_bbox, det_label = self.bbox_head[-1].get_bboxes(
rois[i],
cls_score[i],
bbox_pred[i],
img_shapes[i],
scale_factors[i],
rescale=rescale,
cfg=rcnn_test_cfg)
det_bboxes.append(det_bbox)
det_labels.append(det_label)
bbox_results = [
bbox2result(det_bboxes[i], det_labels[i],
self.bbox_head[-1].num_classes)
for i in range(num_imgs)
]
ms_bbox_result['ensemble'] = bbox_results
if self.with_mask:
if all(det_bbox.shape[0] == 0 for det_bbox in det_bboxes):
mask_classes = self.mask_head[-1].num_classes
segm_results = [[[] for _ in range(mask_classes)]
for _ in range(num_imgs)]
else:
if rescale and not isinstance(scale_factors[0], float):
scale_factors = [
torch.from_numpy(scale_factor).to(det_bboxes[0].device)
for scale_factor in scale_factors
]
_bboxes = [
det_bboxes[i][:, :4] *
scale_factors[i] if rescale else det_bboxes[i][:, :4]
for i in range(len(det_bboxes))
]
mask_rois = bbox2roi(_bboxes)
num_mask_rois_per_img = tuple(
_bbox.size(0) for _bbox in _bboxes)
aug_masks = []
for i in range(self.num_stages):
mask_results = self._mask_forward(i, x, mask_rois)
mask_pred = mask_results['mask_pred']
# split batch mask prediction back to each image
mask_pred = mask_pred.split(num_mask_rois_per_img, 0)
aug_masks.append([
m.sigmoid().cpu().detach().numpy() for m in mask_pred
])
# apply mask post-processing to each image individually
segm_results = []
for i in range(num_imgs):
if det_bboxes[i].shape[0] == 0:
segm_results.append(
[[]
for _ in range(self.mask_head[-1].num_classes)])
else:
aug_mask = [mask[i] for mask in aug_masks]
merged_masks = merge_aug_masks(
aug_mask, [[img_metas[i]]] * self.num_stages,
rcnn_test_cfg)
segm_result = self.mask_head[-1].get_seg_masks(
merged_masks, _bboxes[i], det_labels[i],
rcnn_test_cfg, ori_shapes[i], scale_factors[i],
rescale)
segm_results.append(segm_result)
ms_segm_result['ensemble'] = segm_results
if self.with_mask:
results = list(
zip(ms_bbox_result['ensemble'], ms_segm_result['ensemble']))
else:
results = ms_bbox_result['ensemble']
return results
[docs] def aug_test(self, features, proposal_list, img_metas, rescale=False):
"""Test with augmentations.
If rescale is False, then returned bboxes and masks will fit the scale
of imgs[0].
"""
rcnn_test_cfg = self.test_cfg
aug_bboxes = []
aug_scores = []
for x, img_meta in zip(features, img_metas):
# only one image in the batch
img_shape = img_meta[0]['img_shape']
scale_factor = img_meta[0]['scale_factor']
flip = img_meta[0]['flip']
flip_direction = img_meta[0]['flip_direction']
proposals = bbox_mapping(proposal_list[0][:, :4], img_shape,
scale_factor, flip, flip_direction)
# "ms" in variable names means multi-stage
ms_scores = []
rois = bbox2roi([proposals])
if rois.shape[0] == 0:
# There is no proposal in the single image
aug_bboxes.append(rois.new_zeros(0, 4))
aug_scores.append(rois.new_zeros(0, 1))
continue
for i in range(self.num_stages):
bbox_results = self._bbox_forward(i, x, rois)
ms_scores.append(bbox_results['cls_score'])
if i < self.num_stages - 1:
cls_score = bbox_results['cls_score']
if self.bbox_head[i].custom_activation:
cls_score = self.bbox_head[i].loss_cls.get_activation(
cls_score)
bbox_label = cls_score[:, :-1].argmax(dim=1)
rois = self.bbox_head[i].regress_by_class(
rois, bbox_label, bbox_results['bbox_pred'],
img_meta[0])
cls_score = sum(ms_scores) / float(len(ms_scores))
bboxes, scores = self.bbox_head[-1].get_bboxes(
rois,
cls_score,
bbox_results['bbox_pred'],
img_shape,
scale_factor,
rescale=False,
cfg=None)
aug_bboxes.append(bboxes)
aug_scores.append(scores)
# after merging, bboxes will be rescaled to the original image size
merged_bboxes, merged_scores = merge_aug_bboxes(
aug_bboxes, aug_scores, img_metas, rcnn_test_cfg)
det_bboxes, det_labels = multiclass_nms(merged_bboxes, merged_scores,
rcnn_test_cfg.score_thr,
rcnn_test_cfg.nms,
rcnn_test_cfg.max_per_img)
bbox_result = bbox2result(det_bboxes, det_labels,
self.bbox_head[-1].num_classes)
if self.with_mask:
if det_bboxes.shape[0] == 0:
segm_result = [[]
for _ in range(self.mask_head[-1].num_classes)]
else:
aug_masks = []
aug_img_metas = []
for x, img_meta in zip(features, img_metas):
img_shape = img_meta[0]['img_shape']
scale_factor = img_meta[0]['scale_factor']
flip = img_meta[0]['flip']
flip_direction = img_meta[0]['flip_direction']
_bboxes = bbox_mapping(det_bboxes[:, :4], img_shape,
scale_factor, flip, flip_direction)
mask_rois = bbox2roi([_bboxes])
for i in range(self.num_stages):
mask_results = self._mask_forward(i, x, mask_rois)
aug_masks.append(
mask_results['mask_pred'].sigmoid().cpu().numpy())
aug_img_metas.append(img_meta)
merged_masks = merge_aug_masks(aug_masks, aug_img_metas,
self.test_cfg)
ori_shape = img_metas[0][0]['ori_shape']
dummy_scale_factor = np.ones(4)
segm_result = self.mask_head[-1].get_seg_masks(
merged_masks,
det_bboxes,
det_labels,
rcnn_test_cfg,
ori_shape,
scale_factor=dummy_scale_factor,
rescale=False)
return [(bbox_result, segm_result)]
else:
return [bbox_result]
def onnx_export(self, x, proposals, img_metas):
assert self.with_bbox, 'Bbox head must be implemented.'
assert proposals.shape[0] == 1, 'Only support one input image ' \
'while in exporting to ONNX'
# remove the scores
rois = proposals[..., :-1]
batch_size = rois.shape[0]
num_proposals_per_img = rois.shape[1]
# Eliminate the batch dimension
rois = rois.view(-1, 4)
# add dummy batch index
rois = torch.cat([rois.new_zeros(rois.shape[0], 1), rois], dim=-1)
max_shape = img_metas[0]['img_shape_for_onnx']
ms_scores = []
rcnn_test_cfg = self.test_cfg
for i in range(self.num_stages):
bbox_results = self._bbox_forward(i, x, rois)
cls_score = bbox_results['cls_score']
bbox_pred = bbox_results['bbox_pred']
# Recover the batch dimension
rois = rois.reshape(batch_size, num_proposals_per_img,
rois.size(-1))
cls_score = cls_score.reshape(batch_size, num_proposals_per_img,
cls_score.size(-1))
bbox_pred = bbox_pred.reshape(batch_size, num_proposals_per_img, 4)
ms_scores.append(cls_score)
if i < self.num_stages - 1:
assert self.bbox_head[i].reg_class_agnostic
new_rois = self.bbox_head[i].bbox_coder.decode(
rois[..., 1:], bbox_pred, max_shape=max_shape)
rois = new_rois.reshape(-1, new_rois.shape[-1])
# add dummy batch index
rois = torch.cat([rois.new_zeros(rois.shape[0], 1), rois],
dim=-1)
cls_score = sum(ms_scores) / float(len(ms_scores))
bbox_pred = bbox_pred.reshape(batch_size, num_proposals_per_img, 4)
rois = rois.reshape(batch_size, num_proposals_per_img, -1)
det_bboxes, det_labels = self.bbox_head[-1].onnx_export(
rois, cls_score, bbox_pred, max_shape, cfg=rcnn_test_cfg)
if not self.with_mask:
return det_bboxes, det_labels
else:
batch_index = torch.arange(
det_bboxes.size(0),
device=det_bboxes.device).float().view(-1, 1, 1).expand(
det_bboxes.size(0), det_bboxes.size(1), 1)
rois = det_bboxes[..., :4]
mask_rois = torch.cat([batch_index, rois], dim=-1)
mask_rois = mask_rois.view(-1, 5)
aug_masks = []
for i in range(self.num_stages):
mask_results = self._mask_forward(i, x, mask_rois)
mask_pred = mask_results['mask_pred']
aug_masks.append(mask_pred)
max_shape = img_metas[0]['img_shape_for_onnx']
# calculate the mean of masks from several stage
mask_pred = sum(aug_masks) / len(aug_masks)
segm_results = self.mask_head[-1].onnx_export(
mask_pred, rois.reshape(-1, 4), det_labels.reshape(-1),
self.test_cfg, max_shape)
segm_results = segm_results.reshape(batch_size,
det_bboxes.shape[1],
max_shape[0], max_shape[1])
return det_bboxes, det_labels, segm_results