PaddleOCR/ppocr/modeling/backbones/rec_efficientb3_pren.py

229 lines
8.7 KiB
Python

# copyright (c) 2022 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.
"""
Code is refer from:
https://github.com/RuijieJ/pren/blob/main/Nets/EfficientNet.py
"""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import math
from collections import namedtuple
import paddle
import paddle.nn as nn
import paddle.nn.functional as F
__all__ = ['EfficientNetb3']
class EffB3Params:
@staticmethod
def get_global_params():
"""
The fllowing are efficientnetb3's arch superparams, but to fit for scene
text recognition task, the resolution(image_size) here is changed
from 300 to 64.
"""
GlobalParams = namedtuple('GlobalParams', [
'drop_connect_rate', 'width_coefficient', 'depth_coefficient',
'depth_divisor', 'image_size'
])
global_params = GlobalParams(
drop_connect_rate=0.3,
width_coefficient=1.2,
depth_coefficient=1.4,
depth_divisor=8,
image_size=64)
return global_params
@staticmethod
def get_block_params():
BlockParams = namedtuple('BlockParams', [
'kernel_size', 'num_repeat', 'input_filters', 'output_filters',
'expand_ratio', 'id_skip', 'se_ratio', 'stride'
])
block_params = [
BlockParams(3, 1, 32, 16, 1, True, 0.25, 1),
BlockParams(3, 2, 16, 24, 6, True, 0.25, 2),
BlockParams(5, 2, 24, 40, 6, True, 0.25, 2),
BlockParams(3, 3, 40, 80, 6, True, 0.25, 2),
BlockParams(5, 3, 80, 112, 6, True, 0.25, 1),
BlockParams(5, 4, 112, 192, 6, True, 0.25, 2),
BlockParams(3, 1, 192, 320, 6, True, 0.25, 1)
]
return block_params
class EffUtils:
@staticmethod
def round_filters(filters, global_params):
"""Calculate and round number of filters based on depth multiplier."""
multiplier = global_params.width_coefficient
if not multiplier:
return filters
divisor = global_params.depth_divisor
filters *= multiplier
new_filters = int(filters + divisor / 2) // divisor * divisor
if new_filters < 0.9 * filters:
new_filters += divisor
return int(new_filters)
@staticmethod
def round_repeats(repeats, global_params):
"""Round number of filters based on depth multiplier."""
multiplier = global_params.depth_coefficient
if not multiplier:
return repeats
return int(math.ceil(multiplier * repeats))
class ConvBlock(nn.Layer):
def __init__(self, block_params):
super(ConvBlock, self).__init__()
self.block_args = block_params
self.has_se = (self.block_args.se_ratio is not None) and \
(0 < self.block_args.se_ratio <= 1)
self.id_skip = block_params.id_skip
# expansion phase
self.input_filters = self.block_args.input_filters
output_filters = \
self.block_args.input_filters * self.block_args.expand_ratio
if self.block_args.expand_ratio != 1:
self.expand_conv = nn.Conv2D(
self.input_filters, output_filters, 1, bias_attr=False)
self.bn0 = nn.BatchNorm(output_filters)
# depthwise conv phase
k = self.block_args.kernel_size
s = self.block_args.stride
self.depthwise_conv = nn.Conv2D(
output_filters,
output_filters,
groups=output_filters,
kernel_size=k,
stride=s,
padding='same',
bias_attr=False)
self.bn1 = nn.BatchNorm(output_filters)
# squeeze and excitation layer, if desired
if self.has_se:
num_squeezed_channels = max(1,
int(self.block_args.input_filters *
self.block_args.se_ratio))
self.se_reduce = nn.Conv2D(output_filters, num_squeezed_channels, 1)
self.se_expand = nn.Conv2D(num_squeezed_channels, output_filters, 1)
# output phase
self.final_oup = self.block_args.output_filters
self.project_conv = nn.Conv2D(
output_filters, self.final_oup, 1, bias_attr=False)
self.bn2 = nn.BatchNorm(self.final_oup)
self.swish = nn.Swish()
def drop_connect(self, inputs, p, training):
if not training:
return inputs
batch_size = inputs.shape[0]
keep_prob = 1 - p
random_tensor = keep_prob
random_tensor += paddle.rand([batch_size, 1, 1, 1], dtype=inputs.dtype)
random_tensor = paddle.to_tensor(random_tensor, place=inputs.place)
binary_tensor = paddle.floor(random_tensor)
output = inputs / keep_prob * binary_tensor
return output
def forward(self, inputs, drop_connect_rate=None):
# expansion and depthwise conv
x = inputs
if self.block_args.expand_ratio != 1:
x = self.swish(self.bn0(self.expand_conv(inputs)))
x = self.swish(self.bn1(self.depthwise_conv(x)))
# squeeze and excitation
if self.has_se:
x_squeezed = F.adaptive_avg_pool2d(x, 1)
x_squeezed = self.se_expand(self.swish(self.se_reduce(x_squeezed)))
x = F.sigmoid(x_squeezed) * x
x = self.bn2(self.project_conv(x))
# skip conntection and drop connect
if self.id_skip and self.block_args.stride == 1 and \
self.input_filters == self.final_oup:
if drop_connect_rate:
x = self.drop_connect(
x, p=drop_connect_rate, training=self.training)
x = x + inputs
return x
class EfficientNetb3_PREN(nn.Layer):
def __init__(self, in_channels):
super(EfficientNetb3_PREN, self).__init__()
self.blocks_params = EffB3Params.get_block_params()
self.global_params = EffB3Params.get_global_params()
self.out_channels = []
# stem
stem_channels = EffUtils.round_filters(32, self.global_params)
self.conv_stem = nn.Conv2D(
in_channels, stem_channels, 3, 2, padding='same', bias_attr=False)
self.bn0 = nn.BatchNorm(stem_channels)
self.blocks = []
# to extract three feature maps for fpn based on efficientnetb3 backbone
self.concerned_block_idxes = [7, 17, 25]
concerned_idx = 0
for i, block_params in enumerate(self.blocks_params):
block_params = block_params._replace(
input_filters=EffUtils.round_filters(block_params.input_filters,
self.global_params),
output_filters=EffUtils.round_filters(
block_params.output_filters, self.global_params),
num_repeat=EffUtils.round_repeats(block_params.num_repeat,
self.global_params))
self.blocks.append(
self.add_sublayer("{}-0".format(i), ConvBlock(block_params)))
concerned_idx += 1
if concerned_idx in self.concerned_block_idxes:
self.out_channels.append(block_params.output_filters)
if block_params.num_repeat > 1:
block_params = block_params._replace(
input_filters=block_params.output_filters, stride=1)
for j in range(block_params.num_repeat - 1):
self.blocks.append(
self.add_sublayer('{}-{}'.format(i, j + 1),
ConvBlock(block_params)))
concerned_idx += 1
if concerned_idx in self.concerned_block_idxes:
self.out_channels.append(block_params.output_filters)
self.swish = nn.Swish()
def forward(self, inputs):
outs = []
x = self.swish(self.bn0(self.conv_stem(inputs)))
for idx, block in enumerate(self.blocks):
drop_connect_rate = self.global_params.drop_connect_rate
if drop_connect_rate:
drop_connect_rate *= float(idx) / len(self.blocks)
x = block(x, drop_connect_rate=drop_connect_rate)
if idx in self.concerned_block_idxes:
outs.append(x)
return outs