EasyCV/easycv/models/ocr/backbones/det_resnet_vd.py
yhq 397ecf2658
Feature/paddleocr inference (#148)
* add ocr model and convert weights from paddleocrv3
2022-09-28 14:03:16 +08:00

277 lines
8.5 KiB
Python

# Modified from https://github.com/PaddlePaddle/PaddleOCR/blob/release/2.6/ppocr/modeling/backbones/det_resnet_vd.py
import torch
import torch.nn as nn
import torch.nn.functional as F
from easycv.models.registry import BACKBONES
from .det_mobilenet_v3 import Activation
class ConvBNLayer(nn.Module):
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.act = act
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,
bias=False)
if name == 'conv1':
bn_name = 'bn_' + name
else:
bn_name = 'bn' + name[3:]
self._batch_norm = nn.BatchNorm2d(
out_channels,
track_running_stats=True,
)
if act is not None:
self._act = Activation(act_type=act, inplace=True)
def forward(self, inputs):
if self.is_vd_mode:
inputs = self._pool2d_avg(inputs)
y = self._conv(inputs)
y = self._batch_norm(y)
if self.act is not None:
y = self._act(y)
return y
class BottleneckBlock(nn.Module):
def __init__(self,
in_channels,
out_channels,
stride,
shortcut=True,
if_first=False,
name=None):
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')
if not shortcut:
self.short = ConvBNLayer(
in_channels=in_channels,
out_channels=out_channels * 4,
kernel_size=1,
stride=1,
is_vd_mode=False if if_first else True,
name=name + '_branch1')
self.shortcut = shortcut
def forward(self, inputs):
y = self.conv0(inputs)
conv1 = self.conv1(y)
conv2 = self.conv2(conv1)
if self.shortcut:
short = inputs
else:
short = self.short(inputs)
y = torch.add(short, conv2)
y = F.relu(y)
return y
class BasicBlock(nn.Module):
def __init__(self,
in_channels,
out_channels,
stride,
shortcut=True,
if_first=False,
name=None):
super(BasicBlock, self).__init__()
self.stride = stride
self.conv0 = ConvBNLayer(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=3,
stride=stride,
act='relu',
name=name + '_branch2a')
self.conv1 = ConvBNLayer(
in_channels=out_channels,
out_channels=out_channels,
kernel_size=3,
act=None,
name=name + '_branch2b')
if not shortcut:
self.short = ConvBNLayer(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=1,
stride=1,
is_vd_mode=False if if_first else True,
name=name + '_branch1')
self.shortcut = shortcut
def forward(self, inputs):
y = self.conv0(inputs)
conv1 = self.conv1(y)
if self.shortcut:
short = inputs
else:
short = self.short(inputs)
y = short + conv1
y = F.relu(y)
return y
@BACKBONES.register_module()
class OCRDetResNet(nn.Module):
def __init__(self, in_channels=3, layers=50, **kwargs):
super(OCRDetResNet, self).__init__()
self.layers = layers
supported_layers = [18, 34, 50, 101, 152, 200]
assert layers in supported_layers, \
'supported layers are {} but input layer is {}'.format(
supported_layers, layers)
if layers == 18:
depth = [2, 2, 2, 2]
elif layers == 34 or layers == 50:
depth = [3, 4, 6, 3]
elif layers == 101:
depth = [3, 4, 23, 3]
elif layers == 152:
depth = [3, 8, 36, 3]
elif layers == 200:
depth = [3, 12, 48, 3]
num_channels = [64, 256, 512, 1024
] if layers >= 50 else [64, 64, 128, 256]
num_filters = [64, 128, 256, 512]
self.conv1_1 = ConvBNLayer(
in_channels=in_channels,
out_channels=32,
kernel_size=3,
stride=2,
act='relu',
name='conv1_1')
self.conv1_2 = ConvBNLayer(
in_channels=32,
out_channels=32,
kernel_size=3,
stride=1,
act='relu',
name='conv1_2')
self.conv1_3 = ConvBNLayer(
in_channels=32,
out_channels=64,
kernel_size=3,
stride=1,
act='relu',
name='conv1_3')
self.pool2d_max = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
self.stages = nn.ModuleList()
self.out_channels = []
if layers >= 50:
for block in range(len(depth)):
# block_list = []
block_list = nn.Sequential()
shortcut = False
for i in range(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)
bottleneck_block = BottleneckBlock(
in_channels=num_channels[block]
if i == 0 else num_filters[block] * 4,
out_channels=num_filters[block],
stride=2 if i == 0 and block != 0 else 1,
shortcut=shortcut,
if_first=block == i == 0,
name=conv_name)
shortcut = True
block_list.add_module('bb_%d_%d' % (block, i),
bottleneck_block)
self.out_channels.append(num_filters[block] * 4)
# self.stages.append(nn.Sequential(*block_list))
self.stages.append(block_list)
else:
for block in range(len(depth)):
# block_list = []
block_list = nn.Sequential()
shortcut = False
for i in range(depth[block]):
conv_name = 'res' + str(block + 2) + chr(97 + i)
basic_block = BasicBlock(
in_channels=num_channels[block]
if i == 0 else num_filters[block],
out_channels=num_filters[block],
stride=2 if i == 0 and block != 0 else 1,
shortcut=shortcut,
if_first=block == i == 0,
name=conv_name)
shortcut = True
block_list.add_module('bb_%d_%d' % (block, i), basic_block)
# block_list.append(basic_block)
self.out_channels.append(num_filters[block])
self.stages.append(block_list)
# self.stages.append(nn.Sequential(*block_list))
def forward(self, inputs):
y = self.conv1_1(inputs)
y = self.conv1_2(y)
y = self.conv1_3(y)
y = self.pool2d_max(y)
out = []
for block in self.stages:
y = block(y)
out.append(y)
return out