PaddleOCR/ppocr/modeling/heads/table_att_head.py

132 lines
5.6 KiB
Python

# 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.
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import paddle
import paddle.nn as nn
import paddle.nn.functional as F
import numpy as np
from .rec_att_head import AttentionGRUCell
class TableAttentionHead(nn.Layer):
def __init__(self,
in_channels,
hidden_size,
loc_type,
in_max_len=488,
max_text_length=800,
out_channels=30,
point_num=2,
**kwargs):
super(TableAttentionHead, self).__init__()
self.input_size = in_channels[-1]
self.hidden_size = hidden_size
self.out_channels = out_channels
self.max_text_length = max_text_length
self.structure_attention_cell = AttentionGRUCell(
self.input_size, hidden_size, self.out_channels, use_gru=False)
self.structure_generator = nn.Linear(hidden_size, self.out_channels)
self.loc_type = loc_type
self.in_max_len = in_max_len
if self.loc_type == 1:
self.loc_generator = nn.Linear(hidden_size, 4)
else:
if self.in_max_len == 640:
self.loc_fea_trans = nn.Linear(400, self.max_text_length + 1)
elif self.in_max_len == 800:
self.loc_fea_trans = nn.Linear(625, self.max_text_length + 1)
else:
self.loc_fea_trans = nn.Linear(256, self.max_text_length + 1)
self.loc_generator = nn.Linear(self.input_size + hidden_size,
point_num * 2)
def _char_to_onehot(self, input_char, onehot_dim):
input_ont_hot = F.one_hot(input_char, onehot_dim)
return input_ont_hot
def forward(self, inputs, targets=None):
# if and else branch are both needed when you want to assign a variable
# if you modify the var in just one branch, then the modification will not work.
fea = inputs[-1]
if len(fea.shape) == 3:
pass
else:
last_shape = int(np.prod(fea.shape[2:])) # gry added
fea = paddle.reshape(fea, [fea.shape[0], fea.shape[1], last_shape])
fea = fea.transpose([0, 2, 1]) # (NTC)(batch, width, channels)
batch_size = fea.shape[0]
hidden = paddle.zeros((batch_size, self.hidden_size))
output_hiddens = []
if self.training and targets is not None:
structure = targets[0]
for i in range(self.max_text_length + 1):
elem_onehots = self._char_to_onehot(
structure[:, i], onehot_dim=self.out_channels)
(outputs, hidden), alpha = self.structure_attention_cell(
hidden, fea, elem_onehots)
output_hiddens.append(paddle.unsqueeze(outputs, axis=1))
output = paddle.concat(output_hiddens, axis=1)
structure_probs = self.structure_generator(output)
if self.loc_type == 1:
loc_preds = self.loc_generator(output)
loc_preds = F.sigmoid(loc_preds)
else:
loc_fea = fea.transpose([0, 2, 1])
loc_fea = self.loc_fea_trans(loc_fea)
loc_fea = loc_fea.transpose([0, 2, 1])
loc_concat = paddle.concat([output, loc_fea], axis=2)
loc_preds = self.loc_generator(loc_concat)
loc_preds = F.sigmoid(loc_preds)
else:
temp_elem = paddle.zeros(shape=[batch_size], dtype="int32")
structure_probs = None
loc_preds = None
elem_onehots = None
outputs = None
alpha = None
max_text_length = paddle.to_tensor(self.max_text_length)
i = 0
while i < max_text_length + 1:
elem_onehots = self._char_to_onehot(
temp_elem, onehot_dim=self.out_channels)
(outputs, hidden), alpha = self.structure_attention_cell(
hidden, fea, elem_onehots)
output_hiddens.append(paddle.unsqueeze(outputs, axis=1))
structure_probs_step = self.structure_generator(outputs)
temp_elem = structure_probs_step.argmax(axis=1, dtype="int32")
i += 1
output = paddle.concat(output_hiddens, axis=1)
structure_probs = self.structure_generator(output)
structure_probs = F.softmax(structure_probs)
if self.loc_type == 1:
loc_preds = self.loc_generator(output)
loc_preds = F.sigmoid(loc_preds)
else:
loc_fea = fea.transpose([0, 2, 1])
loc_fea = self.loc_fea_trans(loc_fea)
loc_fea = loc_fea.transpose([0, 2, 1])
loc_concat = paddle.concat([output, loc_fea], axis=2)
loc_preds = self.loc_generator(loc_concat)
loc_preds = F.sigmoid(loc_preds)
return {'structure_probs': structure_probs, 'loc_preds': loc_preds}