PulseFocusPlatform/ppdet/modeling/backbones/senet.py

140 lines
5.0 KiB
Python

# Copyright (c) 2021 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.nn as nn
from ppdet.core.workspace import register, serializable
from .resnet import ResNet, Blocks, BasicBlock, BottleNeck
__all__ = ['SENet', 'SERes5Head']
@register
@serializable
class SENet(ResNet):
__shared__ = ['norm_type']
def __init__(self,
depth=50,
variant='b',
lr_mult_list=[1.0, 1.0, 1.0, 1.0],
groups=1,
base_width=64,
norm_type='bn',
norm_decay=0,
freeze_norm=True,
freeze_at=0,
return_idx=[0, 1, 2, 3],
dcn_v2_stages=[-1],
std_senet=True,
num_stages=4):
"""
Squeeze-and-Excitation Networks, see https://arxiv.org/abs/1709.01507
Args:
depth (int): SENet depth, should be 50, 101, 152
variant (str): ResNet variant, supports 'a', 'b', 'c', 'd' currently
lr_mult_list (list): learning rate ratio of different resnet stages(2,3,4,5),
lower learning rate ratio is need for pretrained model
got using distillation(default as [1.0, 1.0, 1.0, 1.0]).
groups (int): group convolution cardinality
base_width (int): base width of each group convolution
norm_type (str): normalization type, 'bn', 'sync_bn' or 'affine_channel'
norm_decay (float): weight decay for normalization layer weights
freeze_norm (bool): freeze normalization layers
freeze_at (int): freeze the backbone at which stage
return_idx (list): index of the stages whose feature maps are returned
dcn_v2_stages (list): index of stages who select deformable conv v2
std_senet (bool): whether use senet, default True
num_stages (int): total num of stages
"""
super(SENet, self).__init__(
depth=depth,
variant=variant,
lr_mult_list=lr_mult_list,
ch_in=128,
groups=groups,
base_width=base_width,
norm_type=norm_type,
norm_decay=norm_decay,
freeze_norm=freeze_norm,
freeze_at=freeze_at,
return_idx=return_idx,
dcn_v2_stages=dcn_v2_stages,
std_senet=std_senet,
num_stages=num_stages)
@register
class SERes5Head(nn.Layer):
def __init__(self,
depth=50,
variant='b',
lr_mult=1.0,
groups=1,
base_width=64,
norm_type='bn',
norm_decay=0,
dcn_v2=False,
freeze_norm=False,
std_senet=True):
"""
SERes5Head layer
Args:
depth (int): SENet depth, should be 50, 101, 152
variant (str): ResNet variant, supports 'a', 'b', 'c', 'd' currently
lr_mult (list): learning rate ratio of SERes5Head, default as 1.0.
groups (int): group convolution cardinality
base_width (int): base width of each group convolution
norm_type (str): normalization type, 'bn', 'sync_bn' or 'affine_channel'
norm_decay (float): weight decay for normalization layer weights
dcn_v2_stages (list): index of stages who select deformable conv v2
std_senet (bool): whether use senet, default True
"""
super(SERes5Head, self).__init__()
ch_out = 512
ch_in = 256 if depth < 50 else 1024
na = NameAdapter(self)
block = BottleNeck if depth >= 50 else BasicBlock
self.res5 = Blocks(
block,
ch_in,
ch_out,
count=3,
name_adapter=na,
stage_num=5,
variant=variant,
groups=groups,
base_width=base_width,
lr=lr_mult,
norm_type=norm_type,
norm_decay=norm_decay,
freeze_norm=freeze_norm,
dcn_v2=dcn_v2,
std_senet=std_senet)
self.ch_out = ch_out * block.expansion
@property
def out_shape(self):
return [ShapeSpec(
channels=self.ch_out,
stride=16, )]
def forward(self, roi_feat):
y = self.res5(roi_feat)
return y