PaddleOCR/ppocr/modeling/backbones/rec_resnet_fpn.py

308 lines
10 KiB
Python

#copyright (c) 2020 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
from paddle import nn, ParamAttr
from paddle.nn import functional as F
import paddle.fluid as fluid
import paddle
import numpy as np
__all__ = ["ResNetFPN"]
class ResNetFPN(nn.Layer):
def __init__(self, in_channels=1, layers=50, **kwargs):
super(ResNetFPN, self).__init__()
supported_layers = {
18: {
'depth': [2, 2, 2, 2],
'block_class': BasicBlock
},
34: {
'depth': [3, 4, 6, 3],
'block_class': BasicBlock
},
50: {
'depth': [3, 4, 6, 3],
'block_class': BottleneckBlock
},
101: {
'depth': [3, 4, 23, 3],
'block_class': BottleneckBlock
},
152: {
'depth': [3, 8, 36, 3],
'block_class': BottleneckBlock
}
}
stride_list = [(2, 2), (2, 2), (1, 1), (1, 1)]
num_filters = [64, 128, 256, 512]
self.depth = supported_layers[layers]['depth']
self.F = []
self.conv = ConvBNLayer(
in_channels=in_channels,
out_channels=64,
kernel_size=7,
stride=2,
act="relu",
name="conv1")
self.block_list = []
in_ch = 64
if layers >= 50:
for block in range(len(self.depth)):
for i in range(self.depth[block]):
if layers in [101, 152] and block == 2:
if i == 0:
conv_name = "res" + str(block + 2) + "a"
else:
conv_name = "res" + str(block + 2) + "b" + str(i)
else:
conv_name = "res" + str(block + 2) + chr(97 + i)
block_list = self.add_sublayer(
"bottleneckBlock_{}_{}".format(block, i),
BottleneckBlock(
in_channels=in_ch,
out_channels=num_filters[block],
stride=stride_list[block] if i == 0 else 1,
name=conv_name))
in_ch = num_filters[block] * 4
self.block_list.append(block_list)
self.F.append(block_list)
else:
for block in range(len(self.depth)):
for i in range(self.depth[block]):
conv_name = "res" + str(block + 2) + chr(97 + i)
if i == 0 and block != 0:
stride = (2, 1)
else:
stride = (1, 1)
basic_block = self.add_sublayer(
conv_name,
BasicBlock(
in_channels=in_ch,
out_channels=num_filters[block],
stride=stride_list[block] if i == 0 else 1,
is_first=block == i == 0,
name=conv_name))
in_ch = basic_block.out_channels
self.block_list.append(basic_block)
out_ch_list = [in_ch // 4, in_ch // 2, in_ch]
self.base_block = []
self.conv_trans = []
self.bn_block = []
for i in [-2, -3]:
in_channels = out_ch_list[i + 1] + out_ch_list[i]
self.base_block.append(
self.add_sublayer(
"F_{}_base_block_0".format(i),
nn.Conv2D(
in_channels=in_channels,
out_channels=out_ch_list[i],
kernel_size=1,
weight_attr=ParamAttr(trainable=True),
bias_attr=ParamAttr(trainable=True))))
self.base_block.append(
self.add_sublayer(
"F_{}_base_block_1".format(i),
nn.Conv2D(
in_channels=out_ch_list[i],
out_channels=out_ch_list[i],
kernel_size=3,
padding=1,
weight_attr=ParamAttr(trainable=True),
bias_attr=ParamAttr(trainable=True))))
self.base_block.append(
self.add_sublayer(
"F_{}_base_block_2".format(i),
nn.BatchNorm(
num_channels=out_ch_list[i],
act="relu",
param_attr=ParamAttr(trainable=True),
bias_attr=ParamAttr(trainable=True))))
self.base_block.append(
self.add_sublayer(
"F_{}_base_block_3".format(i),
nn.Conv2D(
in_channels=out_ch_list[i],
out_channels=512,
kernel_size=1,
bias_attr=ParamAttr(trainable=True),
weight_attr=ParamAttr(trainable=True))))
self.out_channels = 512
def __call__(self, x):
x = self.conv(x)
fpn_list = []
F = []
for i in range(len(self.depth)):
fpn_list.append(np.sum(self.depth[:i + 1]))
for i, block in enumerate(self.block_list):
x = block(x)
for number in fpn_list:
if i + 1 == number:
F.append(x)
base = F[-1]
j = 0
for i, block in enumerate(self.base_block):
if i % 3 == 0 and i < 6:
j = j + 1
b, c, w, h = F[-j - 1].shape
if [w, h] == list(base.shape[2:]):
base = base
else:
base = self.conv_trans[j - 1](base)
base = self.bn_block[j - 1](base)
base = paddle.concat([base, F[-j - 1]], axis=1)
base = block(base)
return base
class ConvBNLayer(nn.Layer):
def __init__(self,
in_channels,
out_channels,
kernel_size,
stride=1,
groups=1,
act=None,
name=None):
super(ConvBNLayer, self).__init__()
self.conv = nn.Conv2D(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=2 if stride == (1, 1) else kernel_size,
dilation=2 if stride == (1, 1) else 1,
stride=stride,
padding=(kernel_size - 1) // 2,
groups=groups,
weight_attr=ParamAttr(name=name + '.conv2d.output.1.w_0'),
bias_attr=False, )
if name == "conv1":
bn_name = "bn_" + name
else:
bn_name = "bn" + name[3:]
self.bn = nn.BatchNorm(
num_channels=out_channels,
act=act,
param_attr=ParamAttr(name=name + '.output.1.w_0'),
bias_attr=ParamAttr(name=name + '.output.1.b_0'),
moving_mean_name=bn_name + "_mean",
moving_variance_name=bn_name + "_variance")
def __call__(self, x):
x = self.conv(x)
x = self.bn(x)
return x
class ShortCut(nn.Layer):
def __init__(self, in_channels, out_channels, stride, name, is_first=False):
super(ShortCut, self).__init__()
self.use_conv = True
if in_channels != out_channels or stride != 1 or is_first == True:
if stride == (1, 1):
self.conv = ConvBNLayer(
in_channels, out_channels, 1, 1, name=name)
else: # stride==(2,2)
self.conv = ConvBNLayer(
in_channels, out_channels, 1, stride, name=name)
else:
self.use_conv = False
def forward(self, x):
if self.use_conv:
x = self.conv(x)
return x
class BottleneckBlock(nn.Layer):
def __init__(self, in_channels, out_channels, stride, name):
super(BottleneckBlock, self).__init__()
self.conv0 = ConvBNLayer(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=1,
act='relu',
name=name + "_branch2a")
self.conv1 = ConvBNLayer(
in_channels=out_channels,
out_channels=out_channels,
kernel_size=3,
stride=stride,
act='relu',
name=name + "_branch2b")
self.conv2 = ConvBNLayer(
in_channels=out_channels,
out_channels=out_channels * 4,
kernel_size=1,
act=None,
name=name + "_branch2c")
self.short = ShortCut(
in_channels=in_channels,
out_channels=out_channels * 4,
stride=stride,
is_first=False,
name=name + "_branch1")
self.out_channels = out_channels * 4
def forward(self, x):
y = self.conv0(x)
y = self.conv1(y)
y = self.conv2(y)
y = y + self.short(x)
y = F.relu(y)
return y
class BasicBlock(nn.Layer):
def __init__(self, in_channels, out_channels, stride, name, is_first):
super(BasicBlock, self).__init__()
self.conv0 = ConvBNLayer(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=3,
act='relu',
stride=stride,
name=name + "_branch2a")
self.conv1 = ConvBNLayer(
in_channels=out_channels,
out_channels=out_channels,
kernel_size=3,
act=None,
name=name + "_branch2b")
self.short = ShortCut(
in_channels=in_channels,
out_channels=out_channels,
stride=stride,
is_first=is_first,
name=name + "_branch1")
self.out_channels = out_channels
def forward(self, x):
y = self.conv0(x)
y = self.conv1(y)
y = y + self.short(x)
return F.relu(y)