# copyright (c) 2021 PaddlePaddle Authors. All Rights Reserve.
#
# 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.
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import paddle
from paddle import nn
import paddle.nn.functional as F
from paddle import ParamAttr
class ConvBNLayer(nn.Layer):
def __init__(self,
in_channels,
out_channels,
kernel_size,
stride=1,
groups=1,
is_vd_mode=False,
act=None,
name=None):
super(ConvBNLayer, self).__init__()
self.is_vd_mode = is_vd_mode
self._pool2d_avg = nn.AvgPool2D(
kernel_size=2, stride=2, padding=0, ceil_mode=True)
self._conv = nn.Conv2D(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=kernel_size,
stride=stride,
padding=(kernel_size - 1) // 2,
groups=groups,
weight_attr=ParamAttr(name=name + "_weights"),
bias_attr=False)
if name == "conv1":
bn_name = "bn_" + name
else:
bn_name = "bn" + name[3:]
self._batch_norm = nn.BatchNorm(
out_channels,
act=act,
param_attr=ParamAttr(name=bn_name + '_scale'),
bias_attr=ParamAttr(bn_name + '_offset'),
moving_mean_name=bn_name + '_mean',
moving_variance_name=bn_name + '_variance',
use_global_stats=False)
def forward(self, inputs):
y = self._conv(inputs)
y = self._batch_norm(y)
return y
class DeConvBNLayer(nn.Layer):
def __init__(self,
in_channels,
out_channels,
kernel_size=4,
stride=2,
padding=1,
groups=1,
if_act=True,
act=None,
name=None):
super(DeConvBNLayer, self).__init__()
self.if_act = if_act
self.act = act
self.deconv = nn.Conv2DTranspose(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=kernel_size,
stride=stride,
padding=padding,
groups=groups,
weight_attr=ParamAttr(name=name + '_weights'),
bias_attr=False)
self.bn = nn.BatchNorm(
num_channels=out_channels,
act=act,
param_attr=ParamAttr(name="bn_" + name + "_scale"),
bias_attr=ParamAttr(name="bn_" + name + "_offset"),
moving_mean_name="bn_" + name + "_mean",
moving_variance_name="bn_" + name + "_variance",
use_global_stats=False)
def forward(self, x):
x = self.deconv(x)
x = self.bn(x)
return x
class PGFPN(nn.Layer):
def __init__(self, in_channels, **kwargs):
super(PGFPN, self).__init__()
num_inputs = [2048, 2048, 1024, 512, 256]
num_outputs = [256, 256, 192, 192, 128]
self.out_channels = 128
self.conv_bn_layer_1 = ConvBNLayer(
in_channels=3,
out_channels=32,
kernel_size=3,
stride=1,
act=None,
name='FPN_d1')
self.conv_bn_layer_2 = ConvBNLayer(
in_channels=64,
out_channels=64,
kernel_size=3,
stride=1,
act=None,
name='FPN_d2')
self.conv_bn_layer_3 = ConvBNLayer(
in_channels=256,
out_channels=128,
kernel_size=3,
stride=1,
act=None,
name='FPN_d3')
self.conv_bn_layer_4 = ConvBNLayer(
in_channels=32,
out_channels=64,
kernel_size=3,
stride=2,
act=None,
name='FPN_d4')
self.conv_bn_layer_5 = ConvBNLayer(
in_channels=64,
out_channels=64,
kernel_size=3,
stride=1,
act='relu',
name='FPN_d5')
self.conv_bn_layer_6 = ConvBNLayer(
in_channels=64,
out_channels=128,
kernel_size=3,
stride=2,
act=None,
name='FPN_d6')
self.conv_bn_layer_7 = ConvBNLayer(
in_channels=128,
out_channels=128,
kernel_size=3,
stride=1,
act='relu',
name='FPN_d7')
self.conv_bn_layer_8 = ConvBNLayer(
in_channels=128,
out_channels=128,
kernel_size=1,
stride=1,
act=None,
name='FPN_d8')
self.conv_h0 = ConvBNLayer(
in_channels=num_inputs[0],
out_channels=num_outputs[0],
kernel_size=1,
stride=1,
act=None,
name="conv_h{}".format(0))
self.conv_h1 = ConvBNLayer(
in_channels=num_inputs[1],
out_channels=num_outputs[1],
kernel_size=1,
stride=1,
act=None,
name="conv_h{}".format(1))
self.conv_h2 = ConvBNLayer(
in_channels=num_inputs[2],
out_channels=num_outputs[2],
kernel_size=1,
stride=1,
act=None,
name="conv_h{}".format(2))
self.conv_h3 = ConvBNLayer(
in_channels=num_inputs[3],
out_channels=num_outputs[3],
kernel_size=1,
stride=1,
act=None,
name="conv_h{}".format(3))
self.conv_h4 = ConvBNLayer(
in_channels=num_inputs[4],
out_channels=num_outputs[4],
kernel_size=1,
stride=1,
act=None,
name="conv_h{}".format(4))
self.dconv0 = DeConvBNLayer(
in_channels=num_outputs[0],
out_channels=num_outputs[0 + 1],
name="dconv_{}".format(0))
self.dconv1 = DeConvBNLayer(
in_channels=num_outputs[1],
out_channels=num_outputs[1 + 1],
act=None,
name="dconv_{}".format(1))
self.dconv2 = DeConvBNLayer(
in_channels=num_outputs[2],
out_channels=num_outputs[2 + 1],
act=None,
name="dconv_{}".format(2))
self.dconv3 = DeConvBNLayer(
in_channels=num_outputs[3],
out_channels=num_outputs[3 + 1],
act=None,
name="dconv_{}".format(3))
self.conv_g1 = ConvBNLayer(
in_channels=num_outputs[1],
out_channels=num_outputs[1],
kernel_size=3,
stride=1,
act='relu',
name="conv_g{}".format(1))
self.conv_g2 = ConvBNLayer(
in_channels=num_outputs[2],
out_channels=num_outputs[2],
kernel_size=3,
stride=1,
act='relu',
name="conv_g{}".format(2))
self.conv_g3 = ConvBNLayer(
in_channels=num_outputs[3],
out_channels=num_outputs[3],
kernel_size=3,
stride=1,
act='relu',
name="conv_g{}".format(3))
self.conv_g4 = ConvBNLayer(
in_channels=num_outputs[4],
out_channels=num_outputs[4],
kernel_size=3,
stride=1,
act='relu',
name="conv_g{}".format(4))
self.convf = ConvBNLayer(
in_channels=num_outputs[4],
out_channels=num_outputs[4],
kernel_size=1,
stride=1,
act=None,
name="conv_f{}".format(4))
def forward(self, x):
c0, c1, c2, c3, c4, c5, c6 = x
# FPN_Down_Fusion
f = [c0, c1, c2]
g = [None, None, None]
h = [None, None, None]
h[0] = self.conv_bn_layer_1(f[0])
h[1] = self.conv_bn_layer_2(f[1])
h[2] = self.conv_bn_layer_3(f[2])
g[0] = self.conv_bn_layer_4(h[0])
g[1] = paddle.add(g[0], h[1])
g[1] = F.relu(g[1])
g[1] = self.conv_bn_layer_5(g[1])
g[1] = self.conv_bn_layer_6(g[1])
g[2] = paddle.add(g[1], h[2])
g[2] = F.relu(g[2])
g[2] = self.conv_bn_layer_7(g[2])
f_down = self.conv_bn_layer_8(g[2])
# FPN UP Fusion
f1 = [c6, c5, c4, c3, c2]
g = [None, None, None, None, None]
h = [None, None, None, None, None]
h[0] = self.conv_h0(f1[0])
h[1] = self.conv_h1(f1[1])
h[2] = self.conv_h2(f1[2])
h[3] = self.conv_h3(f1[3])
h[4] = self.conv_h4(f1[4])
g[0] = self.dconv0(h[0])
g[1] = paddle.add(g[0], h[1])
g[1] = F.relu(g[1])
g[1] = self.conv_g1(g[1])
g[1] = self.dconv1(g[1])
g[2] = paddle.add(g[1], h[2])
g[2] = F.relu(g[2])
g[2] = self.conv_g2(g[2])
g[2] = self.dconv2(g[2])
g[3] = paddle.add(g[2], h[3])
g[3] = F.relu(g[3])
g[3] = self.conv_g3(g[3])
g[3] = self.dconv3(g[3])
g[4] = paddle.add(x=g[3], y=h[4])
g[4] = F.relu(g[4])
g[4] = self.conv_g4(g[4])
f_up = self.convf(g[4])
f_common = paddle.add(f_down, f_up)
f_common = F.relu(f_common)
return f_common