# 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.
# This code is refer from: https://github.com/PaddlePaddle/PaddleClas/blob/develop/ppcls/arch/backbone/legendary_models/pp_lcnet.py
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import math
import numpy as np
import paddle
from paddle import ParamAttr, reshape, transpose
import paddle.nn as nn
import paddle.nn.functional as F
from paddle.nn import Conv2D, BatchNorm, Linear, Dropout
from paddle.nn import AdaptiveAvgPool2D, MaxPool2D, AvgPool2D
from paddle.nn.initializer import KaimingNormal
from paddle.regularizer import L2Decay
from paddle.nn.functional import hardswish, hardsigmoid
class ConvBNLayer(nn.Layer):
def __init__(self,
num_channels,
filter_size,
num_filters,
stride,
padding,
channels=None,
num_groups=1,
act='hard_swish'):
super(ConvBNLayer, self).__init__()
self._conv = Conv2D(
in_channels=num_channels,
out_channels=num_filters,
kernel_size=filter_size,
stride=stride,
padding=padding,
groups=num_groups,
weight_attr=ParamAttr(initializer=KaimingNormal()),
bias_attr=False)
self._batch_norm = BatchNorm(
num_filters,
act=act,
param_attr=ParamAttr(regularizer=L2Decay(0.0)),
bias_attr=ParamAttr(regularizer=L2Decay(0.0)))
def forward(self, inputs):
y = self._conv(inputs)
y = self._batch_norm(y)
return y
class DepthwiseSeparable(nn.Layer):
def __init__(self,
num_channels,
num_filters1,
num_filters2,
num_groups,
stride,
scale,
dw_size=3,
padding=1,
use_se=False):
super(DepthwiseSeparable, self).__init__()
self.use_se = use_se
self._depthwise_conv = ConvBNLayer(
num_channels=num_channels,
num_filters=int(num_filters1 * scale),
filter_size=dw_size,
stride=stride,
padding=padding,
num_groups=int(num_groups * scale))
if use_se:
self._se = SEModule(int(num_filters1 * scale))
self._pointwise_conv = ConvBNLayer(
num_channels=int(num_filters1 * scale),
filter_size=1,
num_filters=int(num_filters2 * scale),
stride=1,
padding=0)
def forward(self, inputs):
y = self._depthwise_conv(inputs)
if self.use_se:
y = self._se(y)
y = self._pointwise_conv(y)
return y
class MobileNetV1Enhance(nn.Layer):
def __init__(self,
in_channels=3,
scale=0.5,
last_conv_stride=1,
last_pool_type='max',
**kwargs):
super().__init__()
self.scale = scale
self.block_list = []
self.conv1 = ConvBNLayer(
num_channels=3,
filter_size=3,
channels=3,
num_filters=int(32 * scale),
stride=2,
padding=1)
conv2_1 = DepthwiseSeparable(
num_channels=int(32 * scale),
num_filters1=32,
num_filters2=64,
num_groups=32,
stride=1,
scale=scale)
self.block_list.append(conv2_1)
conv2_2 = DepthwiseSeparable(
num_channels=int(64 * scale),
num_filters1=64,
num_filters2=128,
num_groups=64,
stride=1,
scale=scale)
self.block_list.append(conv2_2)
conv3_1 = DepthwiseSeparable(
num_channels=int(128 * scale),
num_filters1=128,
num_filters2=128,
num_groups=128,
stride=1,
scale=scale)
self.block_list.append(conv3_1)
conv3_2 = DepthwiseSeparable(
num_channels=int(128 * scale),
num_filters1=128,
num_filters2=256,
num_groups=128,
stride=(2, 1),
scale=scale)
self.block_list.append(conv3_2)
conv4_1 = DepthwiseSeparable(
num_channels=int(256 * scale),
num_filters1=256,
num_filters2=256,
num_groups=256,
stride=1,
scale=scale)
self.block_list.append(conv4_1)
conv4_2 = DepthwiseSeparable(
num_channels=int(256 * scale),
num_filters1=256,
num_filters2=512,
num_groups=256,
stride=(2, 1),
scale=scale)
self.block_list.append(conv4_2)
for _ in range(5):
conv5 = DepthwiseSeparable(
num_channels=int(512 * scale),
num_filters1=512,
num_filters2=512,
num_groups=512,
stride=1,
dw_size=5,
padding=2,
scale=scale,
use_se=False)
self.block_list.append(conv5)
conv5_6 = DepthwiseSeparable(
num_channels=int(512 * scale),
num_filters1=512,
num_filters2=1024,
num_groups=512,
stride=(2, 1),
dw_size=5,
padding=2,
scale=scale,
use_se=True)
self.block_list.append(conv5_6)
conv6 = DepthwiseSeparable(
num_channels=int(1024 * scale),
num_filters1=1024,
num_filters2=1024,
num_groups=1024,
stride=last_conv_stride,
dw_size=5,
padding=2,
use_se=True,
scale=scale)
self.block_list.append(conv6)
self.block_list = nn.Sequential(*self.block_list)
if last_pool_type == 'avg':
self.pool = nn.AvgPool2D(kernel_size=2, stride=2, padding=0)
else:
self.pool = nn.MaxPool2D(kernel_size=2, stride=2, padding=0)
self.out_channels = int(1024 * scale)
def forward(self, inputs):
y = self.conv1(inputs)
y = self.block_list(y)
y = self.pool(y)
return y
class SEModule(nn.Layer):
def __init__(self, channel, reduction=4):
super(SEModule, self).__init__()
self.avg_pool = AdaptiveAvgPool2D(1)
self.conv1 = Conv2D(
in_channels=channel,
out_channels=channel // reduction,
kernel_size=1,
stride=1,
padding=0,
weight_attr=ParamAttr(),
bias_attr=ParamAttr())
self.conv2 = Conv2D(
in_channels=channel // reduction,
out_channels=channel,
kernel_size=1,
stride=1,
padding=0,
weight_attr=ParamAttr(),
bias_attr=ParamAttr())
def forward(self, inputs):
outputs = self.avg_pool(inputs)
outputs = self.conv1(outputs)
outputs = F.relu(outputs)
outputs = self.conv2(outputs)
outputs = hardsigmoid(outputs)
return paddle.multiply(x=inputs, y=outputs)