import numpy as np
import torch
import torch.nn as nn
from mmcv.cnn import ConvModule
from mmcv.ops import DeformConv2d
from mmdet.core import (build_assigner, build_sampler, images_to_levels,
multi_apply, multiclass_nms, unmap)
from mmdet.core.anchor.point_generator import MlvlPointGenerator
from ..builder import HEADS, build_loss
from .anchor_free_head import AnchorFreeHead
[docs]@HEADS.register_module()
class RepPointsHead(AnchorFreeHead):
"""RepPoint head.
Args:
point_feat_channels (int): Number of channels of points features.
gradient_mul (float): The multiplier to gradients from
points refinement and recognition.
point_strides (Iterable): points strides.
point_base_scale (int): bbox scale for assigning labels.
loss_cls (dict): Config of classification loss.
loss_bbox_init (dict): Config of initial points loss.
loss_bbox_refine (dict): Config of points loss in refinement.
use_grid_points (bool): If we use bounding box representation, the
reppoints is represented as grid points on the bounding box.
center_init (bool): Whether to use center point assignment.
transform_method (str): The methods to transform RepPoints to bbox.
init_cfg (dict or list[dict], optional): Initialization config dict.
""" # noqa: W605
def __init__(self,
num_classes,
in_channels,
point_feat_channels=256,
num_points=9,
gradient_mul=0.1,
point_strides=[8, 16, 32, 64, 128],
point_base_scale=4,
loss_cls=dict(
type='FocalLoss',
use_sigmoid=True,
gamma=2.0,
alpha=0.25,
loss_weight=1.0),
loss_bbox_init=dict(
type='SmoothL1Loss', beta=1.0 / 9.0, loss_weight=0.5),
loss_bbox_refine=dict(
type='SmoothL1Loss', beta=1.0 / 9.0, loss_weight=1.0),
use_grid_points=False,
center_init=True,
transform_method='moment',
moment_mul=0.01,
init_cfg=dict(
type='Normal',
layer='Conv2d',
std=0.01,
override=dict(
type='Normal',
name='reppoints_cls_out',
std=0.01,
bias_prob=0.01)),
**kwargs):
self.num_points = num_points
self.point_feat_channels = point_feat_channels
self.use_grid_points = use_grid_points
self.center_init = center_init
# we use deform conv to extract points features
self.dcn_kernel = int(np.sqrt(num_points))
self.dcn_pad = int((self.dcn_kernel - 1) / 2)
assert self.dcn_kernel * self.dcn_kernel == num_points, \
'The points number should be a square number.'
assert self.dcn_kernel % 2 == 1, \
'The points number should be an odd square number.'
dcn_base = np.arange(-self.dcn_pad,
self.dcn_pad + 1).astype(np.float64)
dcn_base_y = np.repeat(dcn_base, self.dcn_kernel)
dcn_base_x = np.tile(dcn_base, self.dcn_kernel)
dcn_base_offset = np.stack([dcn_base_y, dcn_base_x], axis=1).reshape(
(-1))
self.dcn_base_offset = torch.tensor(dcn_base_offset).view(1, -1, 1, 1)
super().__init__(
num_classes,
in_channels,
loss_cls=loss_cls,
init_cfg=init_cfg,
**kwargs)
self.gradient_mul = gradient_mul
self.point_base_scale = point_base_scale
self.point_strides = point_strides
self.point_generator = MlvlPointGenerator(
self.point_strides, offset=0.)
self.sampling = loss_cls['type'] not in ['FocalLoss']
if self.train_cfg:
self.init_assigner = build_assigner(self.train_cfg.init.assigner)
self.refine_assigner = build_assigner(
self.train_cfg.refine.assigner)
# use PseudoSampler when sampling is False
if self.sampling and hasattr(self.train_cfg, 'sampler'):
sampler_cfg = self.train_cfg.sampler
else:
sampler_cfg = dict(type='PseudoSampler')
self.sampler = build_sampler(sampler_cfg, context=self)
self.transform_method = transform_method
if self.transform_method == 'moment':
self.moment_transfer = nn.Parameter(
data=torch.zeros(2), requires_grad=True)
self.moment_mul = moment_mul
self.use_sigmoid_cls = loss_cls.get('use_sigmoid', False)
if self.use_sigmoid_cls:
self.cls_out_channels = self.num_classes
else:
self.cls_out_channels = self.num_classes + 1
self.loss_bbox_init = build_loss(loss_bbox_init)
self.loss_bbox_refine = build_loss(loss_bbox_refine)
def _init_layers(self):
"""Initialize layers of the head."""
self.relu = nn.ReLU(inplace=True)
self.cls_convs = nn.ModuleList()
self.reg_convs = nn.ModuleList()
for i in range(self.stacked_convs):
chn = self.in_channels if i == 0 else self.feat_channels
self.cls_convs.append(
ConvModule(
chn,
self.feat_channels,
3,
stride=1,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg))
self.reg_convs.append(
ConvModule(
chn,
self.feat_channels,
3,
stride=1,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg))
pts_out_dim = 4 if self.use_grid_points else 2 * self.num_points
self.reppoints_cls_conv = DeformConv2d(self.feat_channels,
self.point_feat_channels,
self.dcn_kernel, 1,
self.dcn_pad)
self.reppoints_cls_out = nn.Conv2d(self.point_feat_channels,
self.cls_out_channels, 1, 1, 0)
self.reppoints_pts_init_conv = nn.Conv2d(self.feat_channels,
self.point_feat_channels, 3,
1, 1)
self.reppoints_pts_init_out = nn.Conv2d(self.point_feat_channels,
pts_out_dim, 1, 1, 0)
self.reppoints_pts_refine_conv = DeformConv2d(self.feat_channels,
self.point_feat_channels,
self.dcn_kernel, 1,
self.dcn_pad)
self.reppoints_pts_refine_out = nn.Conv2d(self.point_feat_channels,
pts_out_dim, 1, 1, 0)
[docs] def points2bbox(self, pts, y_first=True):
"""Converting the points set into bounding box.
:param pts: the input points sets (fields), each points
set (fields) is represented as 2n scalar.
:param y_first: if y_first=True, the point set is represented as
[y1, x1, y2, x2 ... yn, xn], otherwise the point set is
represented as [x1, y1, x2, y2 ... xn, yn].
:return: each points set is converting to a bbox [x1, y1, x2, y2].
"""
pts_reshape = pts.view(pts.shape[0], -1, 2, *pts.shape[2:])
pts_y = pts_reshape[:, :, 0, ...] if y_first else pts_reshape[:, :, 1,
...]
pts_x = pts_reshape[:, :, 1, ...] if y_first else pts_reshape[:, :, 0,
...]
if self.transform_method == 'minmax':
bbox_left = pts_x.min(dim=1, keepdim=True)[0]
bbox_right = pts_x.max(dim=1, keepdim=True)[0]
bbox_up = pts_y.min(dim=1, keepdim=True)[0]
bbox_bottom = pts_y.max(dim=1, keepdim=True)[0]
bbox = torch.cat([bbox_left, bbox_up, bbox_right, bbox_bottom],
dim=1)
elif self.transform_method == 'partial_minmax':
pts_y = pts_y[:, :4, ...]
pts_x = pts_x[:, :4, ...]
bbox_left = pts_x.min(dim=1, keepdim=True)[0]
bbox_right = pts_x.max(dim=1, keepdim=True)[0]
bbox_up = pts_y.min(dim=1, keepdim=True)[0]
bbox_bottom = pts_y.max(dim=1, keepdim=True)[0]
bbox = torch.cat([bbox_left, bbox_up, bbox_right, bbox_bottom],
dim=1)
elif self.transform_method == 'moment':
pts_y_mean = pts_y.mean(dim=1, keepdim=True)
pts_x_mean = pts_x.mean(dim=1, keepdim=True)
pts_y_std = torch.std(pts_y - pts_y_mean, dim=1, keepdim=True)
pts_x_std = torch.std(pts_x - pts_x_mean, dim=1, keepdim=True)
moment_transfer = (self.moment_transfer * self.moment_mul) + (
self.moment_transfer.detach() * (1 - self.moment_mul))
moment_width_transfer = moment_transfer[0]
moment_height_transfer = moment_transfer[1]
half_width = pts_x_std * torch.exp(moment_width_transfer)
half_height = pts_y_std * torch.exp(moment_height_transfer)
bbox = torch.cat([
pts_x_mean - half_width, pts_y_mean - half_height,
pts_x_mean + half_width, pts_y_mean + half_height
],
dim=1)
else:
raise NotImplementedError
return bbox
[docs] def gen_grid_from_reg(self, reg, previous_boxes):
"""Base on the previous bboxes and regression values, we compute the
regressed bboxes and generate the grids on the bboxes.
:param reg: the regression value to previous bboxes.
:param previous_boxes: previous bboxes.
:return: generate grids on the regressed bboxes.
"""
b, _, h, w = reg.shape
bxy = (previous_boxes[:, :2, ...] + previous_boxes[:, 2:, ...]) / 2.
bwh = (previous_boxes[:, 2:, ...] -
previous_boxes[:, :2, ...]).clamp(min=1e-6)
grid_topleft = bxy + bwh * reg[:, :2, ...] - 0.5 * bwh * torch.exp(
reg[:, 2:, ...])
grid_wh = bwh * torch.exp(reg[:, 2:, ...])
grid_left = grid_topleft[:, [0], ...]
grid_top = grid_topleft[:, [1], ...]
grid_width = grid_wh[:, [0], ...]
grid_height = grid_wh[:, [1], ...]
intervel = torch.linspace(0., 1., self.dcn_kernel).view(
1, self.dcn_kernel, 1, 1).type_as(reg)
grid_x = grid_left + grid_width * intervel
grid_x = grid_x.unsqueeze(1).repeat(1, self.dcn_kernel, 1, 1, 1)
grid_x = grid_x.view(b, -1, h, w)
grid_y = grid_top + grid_height * intervel
grid_y = grid_y.unsqueeze(2).repeat(1, 1, self.dcn_kernel, 1, 1)
grid_y = grid_y.view(b, -1, h, w)
grid_yx = torch.stack([grid_y, grid_x], dim=2)
grid_yx = grid_yx.view(b, -1, h, w)
regressed_bbox = torch.cat([
grid_left, grid_top, grid_left + grid_width, grid_top + grid_height
], 1)
return grid_yx, regressed_bbox
[docs] def forward(self, feats):
return multi_apply(self.forward_single, feats)
[docs] def forward_single(self, x):
"""Forward feature map of a single FPN level."""
dcn_base_offset = self.dcn_base_offset.type_as(x)
# If we use center_init, the initial reppoints is from center points.
# If we use bounding bbox representation, the initial reppoints is
# from regular grid placed on a pre-defined bbox.
if self.use_grid_points or not self.center_init:
scale = self.point_base_scale / 2
points_init = dcn_base_offset / dcn_base_offset.max() * scale
bbox_init = x.new_tensor([-scale, -scale, scale,
scale]).view(1, 4, 1, 1)
else:
points_init = 0
cls_feat = x
pts_feat = x
for cls_conv in self.cls_convs:
cls_feat = cls_conv(cls_feat)
for reg_conv in self.reg_convs:
pts_feat = reg_conv(pts_feat)
# initialize reppoints
pts_out_init = self.reppoints_pts_init_out(
self.relu(self.reppoints_pts_init_conv(pts_feat)))
if self.use_grid_points:
pts_out_init, bbox_out_init = self.gen_grid_from_reg(
pts_out_init, bbox_init.detach())
else:
pts_out_init = pts_out_init + points_init
# refine and classify reppoints
pts_out_init_grad_mul = (1 - self.gradient_mul) * pts_out_init.detach(
) + self.gradient_mul * pts_out_init
dcn_offset = pts_out_init_grad_mul - dcn_base_offset
cls_out = self.reppoints_cls_out(
self.relu(self.reppoints_cls_conv(cls_feat, dcn_offset)))
pts_out_refine = self.reppoints_pts_refine_out(
self.relu(self.reppoints_pts_refine_conv(pts_feat, dcn_offset)))
if self.use_grid_points:
pts_out_refine, bbox_out_refine = self.gen_grid_from_reg(
pts_out_refine, bbox_out_init.detach())
else:
pts_out_refine = pts_out_refine + pts_out_init.detach()
return cls_out, pts_out_init, pts_out_refine
[docs] def get_points(self, featmap_sizes, img_metas, device):
"""Get points according to feature map sizes.
Args:
featmap_sizes (list[tuple]): Multi-level feature map sizes.
img_metas (list[dict]): Image meta info.
Returns:
tuple: points of each image, valid flags of each image
"""
num_imgs = len(img_metas)
# since feature map sizes of all images are the same, we only compute
# points center for one time
multi_level_points = self.point_generator.grid_priors(
featmap_sizes, device, with_stride=True)
points_list = [[point.clone() for point in multi_level_points]
for _ in range(num_imgs)]
# for each image, we compute valid flags of multi level grids
valid_flag_list = []
for img_id, img_meta in enumerate(img_metas):
multi_level_flags = self.point_generator.valid_flags(
featmap_sizes, img_meta['pad_shape'])
valid_flag_list.append(multi_level_flags)
return points_list, valid_flag_list
[docs] def centers_to_bboxes(self, point_list):
"""Get bboxes according to center points.
Only used in :class:`MaxIoUAssigner`.
"""
bbox_list = []
for i_img, point in enumerate(point_list):
bbox = []
for i_lvl in range(len(self.point_strides)):
scale = self.point_base_scale * self.point_strides[i_lvl] * 0.5
bbox_shift = torch.Tensor([-scale, -scale, scale,
scale]).view(1, 4).type_as(point[0])
bbox_center = torch.cat(
[point[i_lvl][:, :2], point[i_lvl][:, :2]], dim=1)
bbox.append(bbox_center + bbox_shift)
bbox_list.append(bbox)
return bbox_list
[docs] def offset_to_pts(self, center_list, pred_list):
"""Change from point offset to point coordinate."""
pts_list = []
for i_lvl in range(len(self.point_strides)):
pts_lvl = []
for i_img in range(len(center_list)):
pts_center = center_list[i_img][i_lvl][:, :2].repeat(
1, self.num_points)
pts_shift = pred_list[i_lvl][i_img]
yx_pts_shift = pts_shift.permute(1, 2, 0).view(
-1, 2 * self.num_points)
y_pts_shift = yx_pts_shift[..., 0::2]
x_pts_shift = yx_pts_shift[..., 1::2]
xy_pts_shift = torch.stack([x_pts_shift, y_pts_shift], -1)
xy_pts_shift = xy_pts_shift.view(*yx_pts_shift.shape[:-1], -1)
pts = xy_pts_shift * self.point_strides[i_lvl] + pts_center
pts_lvl.append(pts)
pts_lvl = torch.stack(pts_lvl, 0)
pts_list.append(pts_lvl)
return pts_list
def _point_target_single(self,
flat_proposals,
valid_flags,
gt_bboxes,
gt_bboxes_ignore,
gt_labels,
stage='init',
unmap_outputs=True):
inside_flags = valid_flags
if not inside_flags.any():
return (None, ) * 7
# assign gt and sample proposals
proposals = flat_proposals[inside_flags, :]
if stage == 'init':
assigner = self.init_assigner
pos_weight = self.train_cfg.init.pos_weight
else:
assigner = self.refine_assigner
pos_weight = self.train_cfg.refine.pos_weight
assign_result = assigner.assign(proposals, gt_bboxes, gt_bboxes_ignore,
None if self.sampling else gt_labels)
sampling_result = self.sampler.sample(assign_result, proposals,
gt_bboxes)
num_valid_proposals = proposals.shape[0]
bbox_gt = proposals.new_zeros([num_valid_proposals, 4])
pos_proposals = torch.zeros_like(proposals)
proposals_weights = proposals.new_zeros([num_valid_proposals, 4])
labels = proposals.new_full((num_valid_proposals, ),
self.num_classes,
dtype=torch.long)
label_weights = proposals.new_zeros(
num_valid_proposals, dtype=torch.float)
pos_inds = sampling_result.pos_inds
neg_inds = sampling_result.neg_inds
if len(pos_inds) > 0:
pos_gt_bboxes = sampling_result.pos_gt_bboxes
bbox_gt[pos_inds, :] = pos_gt_bboxes
pos_proposals[pos_inds, :] = proposals[pos_inds, :]
proposals_weights[pos_inds, :] = 1.0
if gt_labels is None:
# Only rpn gives gt_labels as None
# Foreground is the first class
labels[pos_inds] = 0
else:
labels[pos_inds] = gt_labels[
sampling_result.pos_assigned_gt_inds]
if pos_weight <= 0:
label_weights[pos_inds] = 1.0
else:
label_weights[pos_inds] = pos_weight
if len(neg_inds) > 0:
label_weights[neg_inds] = 1.0
# map up to original set of proposals
if unmap_outputs:
num_total_proposals = flat_proposals.size(0)
labels = unmap(labels, num_total_proposals, inside_flags)
label_weights = unmap(label_weights, num_total_proposals,
inside_flags)
bbox_gt = unmap(bbox_gt, num_total_proposals, inside_flags)
pos_proposals = unmap(pos_proposals, num_total_proposals,
inside_flags)
proposals_weights = unmap(proposals_weights, num_total_proposals,
inside_flags)
return (labels, label_weights, bbox_gt, pos_proposals,
proposals_weights, pos_inds, neg_inds)
[docs] def get_targets(self,
proposals_list,
valid_flag_list,
gt_bboxes_list,
img_metas,
gt_bboxes_ignore_list=None,
gt_labels_list=None,
stage='init',
label_channels=1,
unmap_outputs=True):
"""Compute corresponding GT box and classification targets for
proposals.
Args:
proposals_list (list[list]): Multi level points/bboxes of each
image.
valid_flag_list (list[list]): Multi level valid flags of each
image.
gt_bboxes_list (list[Tensor]): Ground truth bboxes of each image.
img_metas (list[dict]): Meta info of each image.
gt_bboxes_ignore_list (list[Tensor]): Ground truth bboxes to be
ignored.
gt_bboxes_list (list[Tensor]): Ground truth labels of each box.
stage (str): `init` or `refine`. Generate target for init stage or
refine stage
label_channels (int): Channel of label.
unmap_outputs (bool): Whether to map outputs back to the original
set of anchors.
Returns:
tuple:
- labels_list (list[Tensor]): Labels of each level.
- label_weights_list (list[Tensor]): Label weights of each level. # noqa: E501
- bbox_gt_list (list[Tensor]): Ground truth bbox of each level.
- proposal_list (list[Tensor]): Proposals(points/bboxes) of each level. # noqa: E501
- proposal_weights_list (list[Tensor]): Proposal weights of each level. # noqa: E501
- num_total_pos (int): Number of positive samples in all images. # noqa: E501
- num_total_neg (int): Number of negative samples in all images. # noqa: E501
"""
assert stage in ['init', 'refine']
num_imgs = len(img_metas)
assert len(proposals_list) == len(valid_flag_list) == num_imgs
# points number of multi levels
num_level_proposals = [points.size(0) for points in proposals_list[0]]
# concat all level points and flags to a single tensor
for i in range(num_imgs):
assert len(proposals_list[i]) == len(valid_flag_list[i])
proposals_list[i] = torch.cat(proposals_list[i])
valid_flag_list[i] = torch.cat(valid_flag_list[i])
# compute targets for each image
if gt_bboxes_ignore_list is None:
gt_bboxes_ignore_list = [None for _ in range(num_imgs)]
if gt_labels_list is None:
gt_labels_list = [None for _ in range(num_imgs)]
(all_labels, all_label_weights, all_bbox_gt, all_proposals,
all_proposal_weights, pos_inds_list, neg_inds_list) = multi_apply(
self._point_target_single,
proposals_list,
valid_flag_list,
gt_bboxes_list,
gt_bboxes_ignore_list,
gt_labels_list,
stage=stage,
unmap_outputs=unmap_outputs)
# no valid points
if any([labels is None for labels in all_labels]):
return None
# sampled points of all images
num_total_pos = sum([max(inds.numel(), 1) for inds in pos_inds_list])
num_total_neg = sum([max(inds.numel(), 1) for inds in neg_inds_list])
labels_list = images_to_levels(all_labels, num_level_proposals)
label_weights_list = images_to_levels(all_label_weights,
num_level_proposals)
bbox_gt_list = images_to_levels(all_bbox_gt, num_level_proposals)
proposals_list = images_to_levels(all_proposals, num_level_proposals)
proposal_weights_list = images_to_levels(all_proposal_weights,
num_level_proposals)
return (labels_list, label_weights_list, bbox_gt_list, proposals_list,
proposal_weights_list, num_total_pos, num_total_neg)
def loss_single(self, cls_score, pts_pred_init, pts_pred_refine, labels,
label_weights, bbox_gt_init, bbox_weights_init,
bbox_gt_refine, bbox_weights_refine, stride,
num_total_samples_init, num_total_samples_refine):
# classification loss
labels = labels.reshape(-1)
label_weights = label_weights.reshape(-1)
cls_score = cls_score.permute(0, 2, 3,
1).reshape(-1, self.cls_out_channels)
cls_score = cls_score.contiguous()
loss_cls = self.loss_cls(
cls_score,
labels,
label_weights,
avg_factor=num_total_samples_refine)
# points loss
bbox_gt_init = bbox_gt_init.reshape(-1, 4)
bbox_weights_init = bbox_weights_init.reshape(-1, 4)
bbox_pred_init = self.points2bbox(
pts_pred_init.reshape(-1, 2 * self.num_points), y_first=False)
bbox_gt_refine = bbox_gt_refine.reshape(-1, 4)
bbox_weights_refine = bbox_weights_refine.reshape(-1, 4)
bbox_pred_refine = self.points2bbox(
pts_pred_refine.reshape(-1, 2 * self.num_points), y_first=False)
normalize_term = self.point_base_scale * stride
loss_pts_init = self.loss_bbox_init(
bbox_pred_init / normalize_term,
bbox_gt_init / normalize_term,
bbox_weights_init,
avg_factor=num_total_samples_init)
loss_pts_refine = self.loss_bbox_refine(
bbox_pred_refine / normalize_term,
bbox_gt_refine / normalize_term,
bbox_weights_refine,
avg_factor=num_total_samples_refine)
return loss_cls, loss_pts_init, loss_pts_refine
[docs] def loss(self,
cls_scores,
pts_preds_init,
pts_preds_refine,
gt_bboxes,
gt_labels,
img_metas,
gt_bboxes_ignore=None):
featmap_sizes = [featmap.size()[-2:] for featmap in cls_scores]
device = cls_scores[0].device
label_channels = self.cls_out_channels if self.use_sigmoid_cls else 1
# target for initial stage
center_list, valid_flag_list = self.get_points(featmap_sizes,
img_metas, device)
pts_coordinate_preds_init = self.offset_to_pts(center_list,
pts_preds_init)
if self.train_cfg.init.assigner['type'] == 'PointAssigner':
# Assign target for center list
candidate_list = center_list
else:
# transform center list to bbox list and
# assign target for bbox list
bbox_list = self.centers_to_bboxes(center_list)
candidate_list = bbox_list
cls_reg_targets_init = self.get_targets(
candidate_list,
valid_flag_list,
gt_bboxes,
img_metas,
gt_bboxes_ignore_list=gt_bboxes_ignore,
gt_labels_list=gt_labels,
stage='init',
label_channels=label_channels)
(*_, bbox_gt_list_init, candidate_list_init, bbox_weights_list_init,
num_total_pos_init, num_total_neg_init) = cls_reg_targets_init
num_total_samples_init = (
num_total_pos_init +
num_total_neg_init if self.sampling else num_total_pos_init)
# target for refinement stage
center_list, valid_flag_list = self.get_points(featmap_sizes,
img_metas, device)
pts_coordinate_preds_refine = self.offset_to_pts(
center_list, pts_preds_refine)
bbox_list = []
for i_img, center in enumerate(center_list):
bbox = []
for i_lvl in range(len(pts_preds_refine)):
bbox_preds_init = self.points2bbox(
pts_preds_init[i_lvl].detach())
bbox_shift = bbox_preds_init * self.point_strides[i_lvl]
bbox_center = torch.cat(
[center[i_lvl][:, :2], center[i_lvl][:, :2]], dim=1)
bbox.append(bbox_center +
bbox_shift[i_img].permute(1, 2, 0).reshape(-1, 4))
bbox_list.append(bbox)
cls_reg_targets_refine = self.get_targets(
bbox_list,
valid_flag_list,
gt_bboxes,
img_metas,
gt_bboxes_ignore_list=gt_bboxes_ignore,
gt_labels_list=gt_labels,
stage='refine',
label_channels=label_channels)
(labels_list, label_weights_list, bbox_gt_list_refine,
candidate_list_refine, bbox_weights_list_refine, num_total_pos_refine,
num_total_neg_refine) = cls_reg_targets_refine
num_total_samples_refine = (
num_total_pos_refine +
num_total_neg_refine if self.sampling else num_total_pos_refine)
# compute loss
losses_cls, losses_pts_init, losses_pts_refine = multi_apply(
self.loss_single,
cls_scores,
pts_coordinate_preds_init,
pts_coordinate_preds_refine,
labels_list,
label_weights_list,
bbox_gt_list_init,
bbox_weights_list_init,
bbox_gt_list_refine,
bbox_weights_list_refine,
self.point_strides,
num_total_samples_init=num_total_samples_init,
num_total_samples_refine=num_total_samples_refine)
loss_dict_all = {
'loss_cls': losses_cls,
'loss_pts_init': losses_pts_init,
'loss_pts_refine': losses_pts_refine
}
return loss_dict_all
[docs] def get_bboxes(self,
cls_scores,
pts_preds_init,
pts_preds_refine,
img_metas,
cfg=None,
rescale=False,
with_nms=True):
assert len(cls_scores) == len(pts_preds_refine)
device = cls_scores[0].device
bbox_preds_refine = [
self.points2bbox(pts_pred_refine)
for pts_pred_refine in pts_preds_refine
]
num_levels = len(cls_scores)
featmap_sizes = [
cls_scores[i].size()[-2:] for i in range(len(cls_scores))
]
multi_level_points = self.point_generator.grid_priors(
featmap_sizes, device)
result_list = []
for img_id in range(len(img_metas)):
cls_score_list = [cls_scores[i][img_id] for i in range(num_levels)]
bbox_pred_list = [
bbox_preds_refine[i][img_id] for i in range(num_levels)
]
img_shape = img_metas[img_id]['img_shape']
scale_factor = img_metas[img_id]['scale_factor']
proposals = self._get_bboxes_single(cls_score_list, bbox_pred_list,
multi_level_points, img_shape,
scale_factor, cfg, rescale,
with_nms)
result_list.append(proposals)
return result_list
def _get_bboxes_single(self,
cls_scores,
bbox_preds,
mlvl_points,
img_shape,
scale_factor,
cfg,
rescale=False,
with_nms=True):
cfg = self.test_cfg if cfg is None else cfg
assert len(cls_scores) == len(bbox_preds) == len(mlvl_points)
mlvl_bboxes = []
mlvl_scores = []
for i_lvl, (cls_score, bbox_pred, points) in enumerate(
zip(cls_scores, bbox_preds, mlvl_points)):
assert cls_score.size()[-2:] == bbox_pred.size()[-2:]
cls_score = cls_score.permute(1, 2,
0).reshape(-1, self.cls_out_channels)
if self.use_sigmoid_cls:
scores = cls_score.sigmoid()
else:
scores = cls_score.softmax(-1)
bbox_pred = bbox_pred.permute(1, 2, 0).reshape(-1, 4)
nms_pre = cfg.get('nms_pre', -1)
if nms_pre > 0 and scores.shape[0] > nms_pre:
if self.use_sigmoid_cls:
max_scores, _ = scores.max(dim=1)
else:
# remind that we set FG labels to [0, num_class-1]
# since mmdet v2.0
# BG cat_id: num_class
max_scores, _ = scores[:, :-1].max(dim=1)
_, topk_inds = max_scores.topk(nms_pre)
points = points[topk_inds, :]
bbox_pred = bbox_pred[topk_inds, :]
scores = scores[topk_inds, :]
bbox_pos_center = torch.cat([points[:, :2], points[:, :2]], dim=1)
bboxes = bbox_pred * self.point_strides[i_lvl] + bbox_pos_center
x1 = bboxes[:, 0].clamp(min=0, max=img_shape[1])
y1 = bboxes[:, 1].clamp(min=0, max=img_shape[0])
x2 = bboxes[:, 2].clamp(min=0, max=img_shape[1])
y2 = bboxes[:, 3].clamp(min=0, max=img_shape[0])
bboxes = torch.stack([x1, y1, x2, y2], dim=-1)
mlvl_bboxes.append(bboxes)
mlvl_scores.append(scores)
mlvl_bboxes = torch.cat(mlvl_bboxes)
if rescale:
mlvl_bboxes /= mlvl_bboxes.new_tensor(scale_factor)
mlvl_scores = torch.cat(mlvl_scores)
if self.use_sigmoid_cls:
# Add a dummy background class to the backend when using sigmoid
# remind that we set FG labels to [0, num_class-1] since mmdet v2.0
# BG cat_id: num_class
padding = mlvl_scores.new_zeros(mlvl_scores.shape[0], 1)
mlvl_scores = torch.cat([mlvl_scores, padding], dim=1)
if with_nms:
det_bboxes, det_labels = multiclass_nms(mlvl_bboxes, mlvl_scores,
cfg.score_thr, cfg.nms,
cfg.max_per_img)
return det_bboxes, det_labels
else:
return mlvl_bboxes, mlvl_scores