PaddleOCR/ppocr/modeling/heads/det_db_head.py

129 lines
4.6 KiB
Python

# copyright (c) 2019 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 math
import paddle
from paddle import nn
import paddle.nn.functional as F
from paddle import ParamAttr
def get_bias_attr(k, name):
stdv = 1.0 / math.sqrt(k * 1.0)
initializer = paddle.nn.initializer.Uniform(-stdv, stdv)
bias_attr = ParamAttr(initializer=initializer, name=name + "_b_attr")
return bias_attr
class Head(nn.Layer):
def __init__(self, in_channels, name_list):
super(Head, self).__init__()
self.conv1 = nn.Conv2D(
in_channels=in_channels,
out_channels=in_channels // 4,
kernel_size=3,
padding=1,
weight_attr=ParamAttr(name=name_list[0] + '.w_0'),
bias_attr=False)
self.conv_bn1 = nn.BatchNorm(
num_channels=in_channels // 4,
param_attr=ParamAttr(
name=name_list[1] + '.w_0',
initializer=paddle.nn.initializer.Constant(value=1.0)),
bias_attr=ParamAttr(
name=name_list[1] + '.b_0',
initializer=paddle.nn.initializer.Constant(value=1e-4)),
moving_mean_name=name_list[1] + '.w_1',
moving_variance_name=name_list[1] + '.w_2',
act='relu')
self.conv2 = nn.Conv2DTranspose(
in_channels=in_channels // 4,
out_channels=in_channels // 4,
kernel_size=2,
stride=2,
weight_attr=ParamAttr(
name=name_list[2] + '.w_0',
initializer=paddle.nn.initializer.KaimingUniform()),
bias_attr=get_bias_attr(in_channels // 4, name_list[-1] + "conv2"))
self.conv_bn2 = nn.BatchNorm(
num_channels=in_channels // 4,
param_attr=ParamAttr(
name=name_list[3] + '.w_0',
initializer=paddle.nn.initializer.Constant(value=1.0)),
bias_attr=ParamAttr(
name=name_list[3] + '.b_0',
initializer=paddle.nn.initializer.Constant(value=1e-4)),
moving_mean_name=name_list[3] + '.w_1',
moving_variance_name=name_list[3] + '.w_2',
act="relu")
self.conv3 = nn.Conv2DTranspose(
in_channels=in_channels // 4,
out_channels=1,
kernel_size=2,
stride=2,
weight_attr=ParamAttr(
name=name_list[4] + '.w_0',
initializer=paddle.nn.initializer.KaimingUniform()),
bias_attr=get_bias_attr(in_channels // 4, name_list[-1] + "conv3"),
)
def forward(self, x):
x = self.conv1(x)
x = self.conv_bn1(x)
x = self.conv2(x)
x = self.conv_bn2(x)
x = self.conv3(x)
x = F.sigmoid(x)
return x
class DBHead(nn.Layer):
"""
Differentiable Binarization (DB) for text detection:
see https://arxiv.org/abs/1911.08947
args:
params(dict): super parameters for build DB network
"""
def __init__(self, in_channels, k=50, **kwargs):
super(DBHead, self).__init__()
self.k = k
binarize_name_list = [
'conv2d_56', 'batch_norm_47', 'conv2d_transpose_0', 'batch_norm_48',
'conv2d_transpose_1', 'binarize'
]
thresh_name_list = [
'conv2d_57', 'batch_norm_49', 'conv2d_transpose_2', 'batch_norm_50',
'conv2d_transpose_3', 'thresh'
]
self.binarize = Head(in_channels, binarize_name_list)
self.thresh = Head(in_channels, thresh_name_list)
def step_function(self, x, y):
return paddle.reciprocal(1 + paddle.exp(-self.k * (x - y)))
def forward(self, x):
shrink_maps = self.binarize(x)
if not self.training:
return {'maps': shrink_maps}
threshold_maps = self.thresh(x)
binary_maps = self.step_function(shrink_maps, threshold_maps)
y = paddle.concat([shrink_maps, threshold_maps, binary_maps], axis=1)
return {'maps': y}