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2024-08-27 14:42:45 +08:00

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# Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import paddle
import paddle.nn as nn
import paddle.nn.functional as F
from ppdet.core.workspace import register
from paddle import ParamAttr
from paddle.nn.initializer import KaimingNormal
from paddle.nn.initializer import Normal, Constant
from ..bbox_utils import batch_distance2bbox
from ..losses import GIoULoss
from ..initializer import bias_init_with_prob, constant_, normal_
from ..assigners.utils import generate_anchors_for_grid_cell
from ppdet.modeling.backbones.cspresnet import ConvBNLayer, RepVggBlock
from ppdet.modeling.ops import get_static_shape, get_act_fn
from ppdet.modeling.layers import MultiClassNMS
__all__ = ['PPYOLOEHead', 'SimpleConvHead']
class ESEAttn(nn.Layer):
def __init__(self, feat_channels, act='swish', attn_conv='convbn'):
super(ESEAttn, self).__init__()
self.fc = nn.Conv2D(feat_channels, feat_channels, 1)
if attn_conv == 'convbn':
self.conv = ConvBNLayer(feat_channels, feat_channels, 1, act=act)
elif attn_conv == 'repvgg':
self.conv = RepVggBlock(feat_channels, feat_channels, act=act)
else:
self.conv = None
self._init_weights()
def _init_weights(self):
normal_(self.fc.weight, std=0.001)
def forward(self, feat, avg_feat):
weight = F.sigmoid(self.fc(avg_feat))
if self.conv:
return self.conv(feat * weight)
else:
return feat * weight
@register
class PPYOLOEHead(nn.Layer):
__shared__ = [
'num_classes', 'eval_size', 'trt', 'exclude_nms',
'exclude_post_process', 'use_shared_conv', 'for_distill'
]
__inject__ = ['static_assigner', 'assigner', 'nms']
def __init__(self,
in_channels=[1024, 512, 256],
num_classes=80,
act='swish',
fpn_strides=(32, 16, 8),
grid_cell_scale=5.0,
grid_cell_offset=0.5,
reg_max=16,
reg_range=None,
static_assigner_epoch=4,
use_varifocal_loss=True,
static_assigner='ATSSAssigner',
assigner='TaskAlignedAssigner',
nms='MultiClassNMS',
eval_size=None,
loss_weight={
'class': 1.0,
'iou': 2.5,
'dfl': 0.5,
},
trt=False,
attn_conv='convbn',
exclude_nms=False,
exclude_post_process=False,
use_shared_conv=True,
for_distill=False):
super(PPYOLOEHead, self).__init__()
assert len(in_channels) > 0, "len(in_channels) should > 0"
self.in_channels = in_channels
self.num_classes = num_classes
self.fpn_strides = fpn_strides
self.grid_cell_scale = grid_cell_scale
self.grid_cell_offset = grid_cell_offset
if reg_range:
self.sm_use = True
self.reg_range = reg_range
else:
self.sm_use = False
self.reg_range = (0, reg_max + 1)
self.reg_channels = self.reg_range[1] - self.reg_range[0]
self.iou_loss = GIoULoss()
self.loss_weight = loss_weight
self.use_varifocal_loss = use_varifocal_loss
self.eval_size = eval_size
self.static_assigner_epoch = static_assigner_epoch
self.static_assigner = static_assigner
self.assigner = assigner
self.nms = nms
if isinstance(self.nms, MultiClassNMS) and trt:
self.nms.trt = trt
self.exclude_nms = exclude_nms
self.exclude_post_process = exclude_post_process
self.use_shared_conv = use_shared_conv
self.for_distill = for_distill
self.is_teacher = False
# stem
self.stem_cls = nn.LayerList()
self.stem_reg = nn.LayerList()
act = get_act_fn(
act, trt=trt) if act is None or isinstance(act,
(str, dict)) else act
for in_c in self.in_channels:
self.stem_cls.append(ESEAttn(in_c, act=act, attn_conv=attn_conv))
self.stem_reg.append(ESEAttn(in_c, act=act, attn_conv=attn_conv))
# pred head
self.pred_cls = nn.LayerList()
self.pred_reg = nn.LayerList()
for in_c in self.in_channels:
self.pred_cls.append(
nn.Conv2D(
in_c, self.num_classes, 3, padding=1))
self.pred_reg.append(
nn.Conv2D(
in_c, 4 * self.reg_channels, 3, padding=1))
# projection conv
self.proj_conv = nn.Conv2D(self.reg_channels, 1, 1, bias_attr=False)
self.proj_conv.skip_quant = True
self._init_weights()
if self.for_distill:
self.distill_pairs = {}
@classmethod
def from_config(cls, cfg, input_shape):
return {'in_channels': [i.channels for i in input_shape], }
def _init_weights(self):
bias_cls = bias_init_with_prob(0.01)
for cls_, reg_ in zip(self.pred_cls, self.pred_reg):
constant_(cls_.weight)
constant_(cls_.bias, bias_cls)
constant_(reg_.weight)
constant_(reg_.bias, 1.0)
proj = paddle.linspace(self.reg_range[0], self.reg_range[1] - 1,
self.reg_channels).reshape(
[1, self.reg_channels, 1, 1])
self.proj_conv.weight.set_value(proj)
self.proj_conv.weight.stop_gradient = True
if self.eval_size:
anchor_points, stride_tensor = self._generate_anchors()
self.anchor_points = anchor_points
self.stride_tensor = stride_tensor
def forward_train(self, feats, targets, aux_pred=None):
anchors, anchor_points, num_anchors_list, stride_tensor = \
generate_anchors_for_grid_cell(
feats, self.fpn_strides, self.grid_cell_scale,
self.grid_cell_offset)
cls_score_list, reg_distri_list = [], []
for i, feat in enumerate(feats):
avg_feat = F.adaptive_avg_pool2d(feat, (1, 1))
cls_logit = self.pred_cls[i](self.stem_cls[i](feat, avg_feat) +
feat)
reg_distri = self.pred_reg[i](self.stem_reg[i](feat, avg_feat))
# cls and reg
cls_score = F.sigmoid(cls_logit)
cls_score_list.append(cls_score.flatten(2).transpose([0, 2, 1]))
reg_distri_list.append(reg_distri.flatten(2).transpose([0, 2, 1]))
cls_score_list = paddle.concat(cls_score_list, axis=1)
reg_distri_list = paddle.concat(reg_distri_list, axis=1)
if targets.get('is_teacher', False):
pred_deltas, pred_dfls = self._bbox_decode_fake(reg_distri_list)
return cls_score_list, pred_deltas * stride_tensor, pred_dfls
if targets.get('get_data', False):
pred_deltas, pred_dfls = self._bbox_decode_fake(reg_distri_list)
return cls_score_list, pred_deltas * stride_tensor, pred_dfls
return self.get_loss([
cls_score_list, reg_distri_list, anchors, anchor_points,
num_anchors_list, stride_tensor
], targets, aux_pred)
def _generate_anchors(self, feats=None, dtype='float32'):
# just use in eval time
anchor_points = []
stride_tensor = []
for i, stride in enumerate(self.fpn_strides):
if feats is not None:
_, _, h, w = feats[i].shape
else:
h = int(self.eval_size[0] / stride)
w = int(self.eval_size[1] / stride)
shift_x = paddle.arange(end=w) + self.grid_cell_offset
shift_y = paddle.arange(end=h) + self.grid_cell_offset
shift_y, shift_x = paddle.meshgrid(shift_y, shift_x)
anchor_point = paddle.cast(
paddle.stack(
[shift_x, shift_y], axis=-1), dtype=dtype)
anchor_points.append(anchor_point.reshape([-1, 2]))
stride_tensor.append(paddle.full([h * w, 1], stride, dtype=dtype))
anchor_points = paddle.concat(anchor_points)
stride_tensor = paddle.concat(stride_tensor)
return anchor_points, stride_tensor
def forward_eval(self, feats):
if self.eval_size:
anchor_points, stride_tensor = self.anchor_points, self.stride_tensor
else:
anchor_points, stride_tensor = self._generate_anchors(feats)
cls_score_list, reg_dist_list = [], []
for i, feat in enumerate(feats):
_, _, h, w = feat.shape
l = h * w
avg_feat = F.adaptive_avg_pool2d(feat, (1, 1))
cls_logit = self.pred_cls[i](self.stem_cls[i](feat, avg_feat) +
feat)
reg_dist = self.pred_reg[i](self.stem_reg[i](feat, avg_feat))
reg_dist = reg_dist.reshape(
[-1, 4, self.reg_channels, l]).transpose([0, 2, 3, 1])
if self.use_shared_conv:
reg_dist = self.proj_conv(F.softmax(
reg_dist, axis=1)).squeeze(1)
else:
reg_dist = F.softmax(reg_dist, axis=1)
# cls and reg
cls_score = F.sigmoid(cls_logit)
cls_score_list.append(cls_score.reshape([-1, self.num_classes, l]))
reg_dist_list.append(reg_dist)
cls_score_list = paddle.concat(cls_score_list, axis=-1)
if self.use_shared_conv:
reg_dist_list = paddle.concat(reg_dist_list, axis=1)
else:
reg_dist_list = paddle.concat(reg_dist_list, axis=2)
reg_dist_list = self.proj_conv(reg_dist_list).squeeze(1)
return cls_score_list, reg_dist_list, anchor_points, stride_tensor
def forward(self, feats, targets=None, aux_pred=None):
assert len(feats) == len(self.fpn_strides), \
"The size of feats is not equal to size of fpn_strides"
if self.training:
return self.forward_train(feats, targets, aux_pred)
else:
if targets is not None:
# only for semi-det
self.is_teacher = targets.get('is_teacher', False)
if self.is_teacher:
return self.forward_train(feats, targets, aux_pred=None)
else:
return self.forward_eval(feats)
return self.forward_eval(feats)
@staticmethod
def _focal_loss(score, label, alpha=0.25, gamma=2.0):
weight = (score - label).pow(gamma)
if alpha > 0:
alpha_t = alpha * label + (1 - alpha) * (1 - label)
weight *= alpha_t
loss = F.binary_cross_entropy(
score, label, weight=weight, reduction='sum')
return loss
@staticmethod
def _varifocal_loss(pred_score, gt_score, label, alpha=0.75, gamma=2.0):
weight = alpha * pred_score.pow(gamma) * (1 - label) + gt_score * label
loss = F.binary_cross_entropy(
pred_score, gt_score, weight=weight, reduction='sum')
return loss
def _bbox_decode(self, anchor_points, pred_dist):
_, l, _ = get_static_shape(pred_dist)
pred_dist = F.softmax(pred_dist.reshape([-1, l, 4, self.reg_channels]))
pred_dist = self.proj_conv(pred_dist.transpose([0, 3, 1, 2])).squeeze(1)
return batch_distance2bbox(anchor_points, pred_dist)
def _bbox_decode_fake(self, pred_dist):
_, l, _ = get_static_shape(pred_dist)
pred_dist_dfl = F.softmax(
pred_dist.reshape([-1, l, 4, self.reg_channels]))
pred_dist = self.proj_conv(pred_dist_dfl.transpose([0, 3, 1, 2
])).squeeze(1)
return pred_dist, pred_dist_dfl
def _bbox2distance(self, points, bbox):
x1y1, x2y2 = paddle.split(bbox, 2, -1)
lt = points - x1y1
rb = x2y2 - points
return paddle.concat([lt, rb], -1).clip(self.reg_range[0],
self.reg_range[1] - 1 - 0.01)
def _df_loss(self, pred_dist, target, lower_bound=0):
target_left = paddle.cast(target.floor(), 'int64')
target_right = target_left + 1
weight_left = target_right.astype('float32') - target
weight_right = 1 - weight_left
loss_left = F.cross_entropy(
pred_dist, target_left - lower_bound,
reduction='none') * weight_left
loss_right = F.cross_entropy(
pred_dist, target_right - lower_bound,
reduction='none') * weight_right
return (loss_left + loss_right).mean(-1, keepdim=True)
def _bbox_loss(self, pred_dist, pred_bboxes, anchor_points, assigned_labels,
assigned_bboxes, assigned_scores, assigned_scores_sum):
# select positive samples mask
mask_positive = (assigned_labels != self.num_classes)
if self.for_distill:
# only used for LD main_kd distill
self.distill_pairs['mask_positive_select'] = mask_positive
num_pos = mask_positive.sum()
# pos/neg loss
if num_pos > 0:
# l1 + iou
bbox_mask = mask_positive.astype('int32').unsqueeze(-1).tile(
[1, 1, 4]).astype('bool')
pred_bboxes_pos = paddle.masked_select(pred_bboxes,
bbox_mask).reshape([-1, 4])
assigned_bboxes_pos = paddle.masked_select(
assigned_bboxes, bbox_mask).reshape([-1, 4])
bbox_weight = paddle.masked_select(
assigned_scores.sum(-1), mask_positive).unsqueeze(-1)
loss_l1 = F.l1_loss(pred_bboxes_pos, assigned_bboxes_pos)
loss_iou = self.iou_loss(pred_bboxes_pos,
assigned_bboxes_pos) * bbox_weight
loss_iou = loss_iou.sum() / assigned_scores_sum
dist_mask = mask_positive.unsqueeze(-1).astype('int32').tile(
[1, 1, self.reg_channels * 4]).astype('bool')
pred_dist_pos = paddle.masked_select(
pred_dist, dist_mask).reshape([-1, 4, self.reg_channels])
assigned_ltrb = self._bbox2distance(anchor_points, assigned_bboxes)
assigned_ltrb_pos = paddle.masked_select(
assigned_ltrb, bbox_mask).reshape([-1, 4])
loss_dfl = self._df_loss(pred_dist_pos, assigned_ltrb_pos,
self.reg_range[0]) * bbox_weight
loss_dfl = loss_dfl.sum() / assigned_scores_sum
if self.for_distill:
self.distill_pairs['pred_bboxes_pos'] = pred_bboxes_pos
self.distill_pairs['pred_dist_pos'] = pred_dist_pos
self.distill_pairs['bbox_weight'] = bbox_weight
else:
loss_l1 = paddle.zeros([1])
loss_iou = paddle.zeros([1])
loss_dfl = pred_dist.sum() * 0.
return loss_l1, loss_iou, loss_dfl
def get_loss(self, head_outs, gt_meta, aux_pred=None):
pred_scores, pred_distri, anchors,\
anchor_points, num_anchors_list, stride_tensor = head_outs
anchor_points_s = anchor_points / stride_tensor
pred_bboxes = self._bbox_decode(anchor_points_s, pred_distri)
if aux_pred is not None:
pred_scores_aux = aux_pred[0]
pred_bboxes_aux = self._bbox_decode(anchor_points_s, aux_pred[1])
gt_labels = gt_meta['gt_class']
gt_bboxes = gt_meta['gt_bbox']
pad_gt_mask = gt_meta['pad_gt_mask']
# label assignment
if gt_meta['epoch_id'] < self.static_assigner_epoch:
assigned_labels, assigned_bboxes, assigned_scores = \
self.static_assigner(
anchors,
num_anchors_list,
gt_labels,
gt_bboxes,
pad_gt_mask,
bg_index=self.num_classes,
pred_bboxes=pred_bboxes.detach() * stride_tensor)
alpha_l = 0.25
else:
if self.sm_use:
# only used in smalldet of PPYOLOE-SOD model
assigned_labels, assigned_bboxes, assigned_scores = \
self.assigner(
pred_scores.detach(),
pred_bboxes.detach() * stride_tensor,
anchor_points,
stride_tensor,
gt_labels,
gt_bboxes,
pad_gt_mask,
bg_index=self.num_classes)
else:
if aux_pred is None:
if not hasattr(self, "assigned_labels"):
assigned_labels, assigned_bboxes, assigned_scores = \
self.assigner(
pred_scores.detach(),
pred_bboxes.detach() * stride_tensor,
anchor_points,
num_anchors_list,
gt_labels,
gt_bboxes,
pad_gt_mask,
bg_index=self.num_classes)
if self.for_distill:
self.assigned_labels = assigned_labels
self.assigned_bboxes = assigned_bboxes
self.assigned_scores = assigned_scores
else:
# only used in distill
assigned_labels = self.assigned_labels
assigned_bboxes = self.assigned_bboxes
assigned_scores = self.assigned_scores
else:
assigned_labels, assigned_bboxes, assigned_scores = \
self.assigner(
pred_scores_aux.detach(),
pred_bboxes_aux.detach() * stride_tensor,
anchor_points,
num_anchors_list,
gt_labels,
gt_bboxes,
pad_gt_mask,
bg_index=self.num_classes)
alpha_l = -1
# rescale bbox
assigned_bboxes /= stride_tensor
assign_out_dict = self.get_loss_from_assign(
pred_scores, pred_distri, pred_bboxes, anchor_points_s,
assigned_labels, assigned_bboxes, assigned_scores, alpha_l)
if aux_pred is not None:
assign_out_dict_aux = self.get_loss_from_assign(
aux_pred[0], aux_pred[1], pred_bboxes_aux, anchor_points_s,
assigned_labels, assigned_bboxes, assigned_scores, alpha_l)
loss = {}
for key in assign_out_dict.keys():
loss[key] = assign_out_dict[key] + assign_out_dict_aux[key]
else:
loss = assign_out_dict
return loss
def get_loss_from_assign(self, pred_scores, pred_distri, pred_bboxes,
anchor_points_s, assigned_labels, assigned_bboxes,
assigned_scores, alpha_l):
# cls loss
if self.use_varifocal_loss:
one_hot_label = F.one_hot(assigned_labels,
self.num_classes + 1)[..., :-1]
loss_cls = self._varifocal_loss(pred_scores, assigned_scores,
one_hot_label)
else:
loss_cls = self._focal_loss(pred_scores, assigned_scores, alpha_l)
assigned_scores_sum = assigned_scores.sum()
if paddle.distributed.get_world_size() > 1:
paddle.distributed.all_reduce(assigned_scores_sum)
assigned_scores_sum /= paddle.distributed.get_world_size()
assigned_scores_sum = paddle.clip(assigned_scores_sum, min=1.)
loss_cls /= assigned_scores_sum
if self.for_distill:
self.distill_pairs['pred_cls_scores'] = pred_scores
self.distill_pairs['pos_num'] = assigned_scores_sum
self.distill_pairs['assigned_scores'] = assigned_scores
one_hot_label = F.one_hot(assigned_labels,
self.num_classes + 1)[..., :-1]
self.distill_pairs['target_labels'] = one_hot_label
loss_l1, loss_iou, loss_dfl = \
self._bbox_loss(pred_distri, pred_bboxes, anchor_points_s,
assigned_labels, assigned_bboxes, assigned_scores,
assigned_scores_sum)
loss = self.loss_weight['class'] * loss_cls + \
self.loss_weight['iou'] * loss_iou + \
self.loss_weight['dfl'] * loss_dfl
out_dict = {
'loss': loss,
'loss_cls': loss_cls,
'loss_iou': loss_iou,
'loss_dfl': loss_dfl,
'loss_l1': loss_l1,
}
return out_dict
def post_process(self, head_outs, scale_factor):
pred_scores, pred_dist, anchor_points, stride_tensor = head_outs
pred_bboxes = batch_distance2bbox(anchor_points, pred_dist)
pred_bboxes *= stride_tensor
if self.exclude_post_process:
return paddle.concat(
[pred_bboxes, pred_scores.transpose([0, 2, 1])],
axis=-1), None, None
else:
# scale bbox to origin
scale_y, scale_x = paddle.split(scale_factor, 2, axis=-1)
scale_factor = paddle.concat(
[scale_x, scale_y, scale_x, scale_y],
axis=-1).reshape([-1, 1, 4])
pred_bboxes /= scale_factor
if self.exclude_nms:
# `exclude_nms=True` just use in benchmark
return pred_bboxes, pred_scores, None
else:
bbox_pred, bbox_num, nms_keep_idx = self.nms(pred_bboxes,
pred_scores)
return bbox_pred, bbox_num, nms_keep_idx
def get_activation(name="LeakyReLU"):
if name == "silu":
module = nn.Silu()
elif name == "relu":
module = nn.ReLU()
elif name in ["LeakyReLU", 'leakyrelu', 'lrelu']:
module = nn.LeakyReLU(0.1)
elif name is None:
module = nn.Identity()
else:
raise AttributeError("Unsupported act type: {}".format(name))
return module
class ConvNormLayer(nn.Layer):
def __init__(self,
in_channels,
out_channels,
kernel_size,
stride=1,
padding=0,
dilation=1,
groups=1,
norm_type='gn',
activation="LeakyReLU"):
super(ConvNormLayer, self).__init__()
assert norm_type in ['bn', 'sync_bn', 'syncbn', 'gn', None]
self.conv = nn.Conv2D(
in_channels,
out_channels,
kernel_size,
stride=stride,
padding=padding,
dilation=dilation,
groups=groups,
bias_attr=False,
weight_attr=ParamAttr(initializer=KaimingNormal()))
if norm_type in ['bn', 'sync_bn', 'syncbn']:
self.norm = nn.BatchNorm2D(out_channels)
elif norm_type == 'gn':
self.norm = nn.GroupNorm(num_groups=32, num_channels=out_channels)
else:
self.norm = None
self.act = get_activation(activation)
def forward(self, x):
y = self.conv(x)
if self.norm is not None:
y = self.norm(y)
y = self.act(y)
return y
class ScaleReg(nn.Layer):
"""
Parameter for scaling the regression outputs.
"""
def __init__(self, scale=1.0):
super(ScaleReg, self).__init__()
scale = paddle.to_tensor(scale)
self.scale = self.create_parameter(
shape=[1],
dtype='float32',
default_initializer=nn.initializer.Assign(scale))
def forward(self, x):
return x * self.scale
@register
class SimpleConvHead(nn.Layer):
__shared__ = ['num_classes']
def __init__(self,
num_classes=80,
feat_in=288,
feat_out=288,
num_convs=1,
fpn_strides=[32, 16, 8, 4],
norm_type='gn',
act='LeakyReLU',
prior_prob=0.01,
reg_max=16):
super(SimpleConvHead, self).__init__()
self.num_classes = num_classes
self.feat_in = feat_in
self.feat_out = feat_out
self.num_convs = num_convs
self.fpn_strides = fpn_strides
self.reg_max = reg_max
self.cls_convs = nn.LayerList()
self.reg_convs = nn.LayerList()
for i in range(self.num_convs):
in_c = feat_in if i == 0 else feat_out
self.cls_convs.append(
ConvNormLayer(
in_c,
feat_out,
3,
stride=1,
padding=1,
norm_type=norm_type,
activation=act))
self.reg_convs.append(
ConvNormLayer(
in_c,
feat_out,
3,
stride=1,
padding=1,
norm_type=norm_type,
activation=act))
bias_cls = bias_init_with_prob(prior_prob)
self.gfl_cls = nn.Conv2D(
feat_out,
self.num_classes,
kernel_size=3,
stride=1,
padding=1,
weight_attr=ParamAttr(initializer=Normal(
mean=0.0, std=0.01)),
bias_attr=ParamAttr(initializer=Constant(value=bias_cls)))
self.gfl_reg = nn.Conv2D(
feat_out,
4 * (self.reg_max + 1),
kernel_size=3,
stride=1,
padding=1,
weight_attr=ParamAttr(initializer=Normal(
mean=0.0, std=0.01)),
bias_attr=ParamAttr(initializer=Constant(value=0)))
self.scales = nn.LayerList()
for i in range(len(self.fpn_strides)):
self.scales.append(ScaleReg(1.0))
def forward(self, feats):
cls_scores = []
bbox_preds = []
for x, scale in zip(feats, self.scales):
cls_feat = x
reg_feat = x
for cls_conv in self.cls_convs:
cls_feat = cls_conv(cls_feat)
for reg_conv in self.reg_convs:
reg_feat = reg_conv(reg_feat)
cls_score = self.gfl_cls(cls_feat)
cls_score = F.sigmoid(cls_score)
cls_score = cls_score.flatten(2).transpose([0, 2, 1])
cls_scores.append(cls_score)
bbox_pred = scale(self.gfl_reg(reg_feat))
bbox_pred = bbox_pred.flatten(2).transpose([0, 2, 1])
bbox_preds.append(bbox_pred)
cls_scores = paddle.concat(cls_scores, axis=1)
bbox_preds = paddle.concat(bbox_preds, axis=1)
return cls_scores, bbox_preds