You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

414 lines
15 KiB
Python

8 months ago
# 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 math
import paddle
import paddle.nn as nn
from paddle import ParamAttr
import paddle.nn.functional as F
import numpy as np
from .rec_att_head import AttentionGRUCell
from ppocr.modeling.backbones.rec_svtrnet import DropPath, Identity, Mlp
def get_para_bias_attr(l2_decay, k):
if l2_decay > 0:
regularizer = paddle.regularizer.L2Decay(l2_decay)
stdv = 1.0 / math.sqrt(k * 1.0)
initializer = nn.initializer.Uniform(-stdv, stdv)
else:
regularizer = None
initializer = None
weight_attr = ParamAttr(regularizer=regularizer, initializer=initializer)
bias_attr = ParamAttr(regularizer=regularizer, initializer=initializer)
return [weight_attr, bias_attr]
class TableAttentionHead(nn.Layer):
def __init__(
self,
in_channels,
hidden_size,
in_max_len=488,
max_text_length=800,
out_channels=30,
loc_reg_num=4,
**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.in_max_len = in_max_len
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, loc_reg_num)
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]
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 = paddle.zeros(
(batch_size, self.max_text_length + 1, self.hidden_size)
)
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[:, i, :] = outputs
structure_probs = self.structure_generator(output_hiddens)
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_hiddens, 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)
for i in range(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[:, i, :] = outputs
structure_probs_step = self.structure_generator(outputs)
temp_elem = structure_probs_step.argmax(axis=1, dtype="int32")
structure_probs = self.structure_generator(output_hiddens)
structure_probs = F.softmax(structure_probs)
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_hiddens, 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}
class HWAttention(nn.Layer):
def __init__(
self,
head_dim=32,
qk_scale=None,
attn_drop=0.0,
):
super().__init__()
self.head_dim = head_dim
self.scale = qk_scale or self.head_dim**-0.5
self.attn_drop = nn.Dropout(attn_drop)
def forward(self, x):
B, N, C = x.shape
C = C // 3
qkv = x.reshape([B, N, 3, C // self.head_dim, self.head_dim]).transpose(
[2, 0, 3, 1, 4]
)
q, k, v = qkv.unbind(0)
attn = q @ k.transpose([0, 1, 3, 2]) * self.scale
attn = F.softmax(attn, -1)
attn = self.attn_drop(attn)
x = attn @ v
x = x.transpose([0, 2, 1]).reshape([B, N, C])
return x
def img2windows(img, H_sp, W_sp):
"""
Crop_img: B C H W
"""
B, H, W, C = img.shape
img_reshape = img.reshape([B, H // H_sp, H_sp, W // W_sp, W_sp, C])
img_perm = img_reshape.transpose([0, 1, 3, 2, 4, 5]).reshape([-1, H_sp * W_sp, C])
return img_perm
def windows2img(img_splits_hw, H_sp, W_sp, H, W):
"""
img_splits_hw: B' H W C
"""
B = int(img_splits_hw.shape[0] / (H * W / H_sp / W_sp))
img = img_splits_hw.reshape([B, H // H_sp, W // W_sp, H_sp, W_sp, -1])
img = img.transpose([0, 1, 3, 2, 4, 5]).flatten(1, 4)
return img
class Block(nn.Layer):
def __init__(
self,
dim,
num_heads,
split_h=4,
split_w=4,
h_num_heads=None,
w_num_heads=None,
mlp_ratio=4.0,
qkv_bias=False,
qk_scale=None,
drop=0.0,
attn_drop=0.0,
drop_path=0.0,
act_layer=nn.GELU,
norm_layer=nn.LayerNorm,
eps=1e-6,
):
super().__init__()
self.qkv = nn.Linear(dim, dim * 3, bias_attr=qkv_bias)
self.proj = nn.Linear(dim, dim)
self.split_h = split_h
self.split_w = split_w
mlp_hidden_dim = int(dim * mlp_ratio)
self.norm1 = norm_layer(dim, epsilon=eps)
self.h_num_heads = h_num_heads if h_num_heads is not None else num_heads // 2
self.w_num_heads = w_num_heads if w_num_heads is not None else num_heads // 2
self.head_dim = dim // num_heads
self.mixer = HWAttention(
head_dim=dim // num_heads,
qk_scale=qk_scale,
attn_drop=attn_drop,
)
self.drop_path = DropPath(drop_path) if drop_path > 0.0 else Identity()
self.norm2 = norm_layer(dim, epsilon=eps)
self.mlp = Mlp(
in_features=dim,
hidden_features=mlp_hidden_dim,
act_layer=act_layer,
drop=drop,
)
def forward(self, x):
B, C, H, W = x.shape
x = x.flatten(2).transpose([0, 2, 1])
qkv = self.qkv(x).reshape([B, H, W, 3 * C])
x1 = qkv[:, :, :, : 3 * self.h_num_heads * self.head_dim] # b, h, w, 3ch
x2 = qkv[:, :, :, 3 * self.h_num_heads * self.head_dim :] # b, h, w, 3cw
x1 = self.mixer(img2windows(x1, self.split_h, W)) # b*splith, W, 3ch
x2 = self.mixer(img2windows(x2, H, self.split_w)) # b*splitw, h, 3ch
x1 = windows2img(x1, self.split_h, W, H, W)
x2 = windows2img(x2, H, self.split_w, H, W)
attened_x = paddle.concat([x1, x2], 2)
attened_x = self.proj(attened_x)
x = self.norm1(x + self.drop_path(attened_x))
x = self.norm2(x + self.drop_path(self.mlp(x)))
x = x.transpose([0, 2, 1]).reshape([-1, C, H, W])
return x
class SLAHead(nn.Layer):
def __init__(
self,
in_channels,
hidden_size,
out_channels=30,
max_text_length=500,
loc_reg_num=4,
fc_decay=0.0,
use_attn=False,
**kwargs,
):
"""
@param in_channels: input shape
@param hidden_size: hidden_size for RNN and Embedding
@param out_channels: num_classes to rec
@param max_text_length: max text pred
"""
super().__init__()
in_channels = in_channels[-1]
self.hidden_size = hidden_size
self.max_text_length = max_text_length
self.emb = self._char_to_onehot
self.num_embeddings = out_channels
self.loc_reg_num = loc_reg_num
self.eos = self.num_embeddings - 1
# structure
self.structure_attention_cell = AttentionGRUCell(
in_channels, hidden_size, self.num_embeddings
)
weight_attr, bias_attr = get_para_bias_attr(l2_decay=fc_decay, k=hidden_size)
weight_attr1_1, bias_attr1_1 = get_para_bias_attr(
l2_decay=fc_decay, k=hidden_size
)
weight_attr1_2, bias_attr1_2 = get_para_bias_attr(
l2_decay=fc_decay, k=hidden_size
)
self.structure_generator = nn.Sequential(
nn.Linear(
self.hidden_size,
self.hidden_size,
weight_attr=weight_attr1_2,
bias_attr=bias_attr1_2,
),
nn.Linear(
hidden_size, out_channels, weight_attr=weight_attr, bias_attr=bias_attr
),
)
dpr = np.linspace(0, 0.1, 2)
self.use_attn = use_attn
if use_attn:
layer_list = [
Block(
in_channels,
num_heads=2,
mlp_ratio=4.0,
qkv_bias=True,
drop_path=dpr[i],
)
for i in range(2)
]
self.cross_atten = nn.Sequential(*layer_list)
# loc
weight_attr1, bias_attr1 = get_para_bias_attr(
l2_decay=fc_decay, k=self.hidden_size
)
weight_attr2, bias_attr2 = get_para_bias_attr(
l2_decay=fc_decay, k=self.hidden_size
)
self.loc_generator = nn.Sequential(
nn.Linear(
self.hidden_size,
self.hidden_size,
weight_attr=weight_attr1,
bias_attr=bias_attr1,
),
nn.Linear(
self.hidden_size,
loc_reg_num,
weight_attr=weight_attr2,
bias_attr=bias_attr2,
),
nn.Sigmoid(),
)
def forward(self, inputs, targets=None):
fea = inputs[-1]
batch_size = fea.shape[0]
if self.use_attn:
fea = fea + self.cross_atten(fea)
# reshape
fea = paddle.reshape(fea, [fea.shape[0], fea.shape[1], -1])
fea = fea.transpose([0, 2, 1]) # (NTC)(batch, width, channels)
hidden = paddle.zeros((batch_size, self.hidden_size))
structure_preds = paddle.zeros(
(batch_size, self.max_text_length + 1, self.num_embeddings)
)
loc_preds = paddle.zeros(
(batch_size, self.max_text_length + 1, self.loc_reg_num)
)
structure_preds.stop_gradient = True
loc_preds.stop_gradient = True
if self.training and targets is not None:
structure = targets[0]
max_len = targets[-2].max().astype("int32")
for i in range(max_len + 1):
hidden, structure_step, loc_step = self._decode(
structure[:, i], fea, hidden
)
structure_preds[:, i, :] = structure_step
loc_preds[:, i, :] = loc_step
structure_preds = structure_preds[:, : max_len + 1]
loc_preds = loc_preds[:, : max_len + 1]
else:
structure_ids = paddle.zeros(
(batch_size, self.max_text_length + 1), dtype="int32"
)
pre_chars = paddle.zeros(shape=[batch_size], dtype="int32")
max_text_length = paddle.to_tensor(self.max_text_length)
# for export
loc_step, structure_step = None, None
for i in range(max_text_length + 1):
hidden, structure_step, loc_step = self._decode(pre_chars, fea, hidden)
pre_chars = structure_step.argmax(axis=1, dtype="int32")
structure_preds[:, i, :] = structure_step
loc_preds[:, i, :] = loc_step
structure_ids[:, i] = pre_chars
if (structure_ids == self.eos).any(-1).all():
break
if not self.training:
structure_preds = F.softmax(structure_preds[:, : i + 1])
loc_preds = loc_preds[:, : i + 1]
return {"structure_probs": structure_preds, "loc_preds": loc_preds}
def _decode(self, pre_chars, features, hidden):
"""
Predict table label and coordinates for each step
@param pre_chars: Table label in previous step
@param features:
@param hidden: hidden status in previous step
@return:
"""
emb_feature = self.emb(pre_chars)
# output shape is b * self.hidden_size
(output, hidden), alpha = self.structure_attention_cell(
hidden, features, emb_feature
)
# structure
structure_step = self.structure_generator(output)
# loc
loc_step = self.loc_generator(output)
return hidden, structure_step, loc_step
def _char_to_onehot(self, input_char):
input_ont_hot = F.one_hot(input_char, self.num_embeddings)
return input_ont_hot