PaddleOCR/ppocr/losses/rec_aster_loss.py

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2021-07-22 19:58:14 +08:00
# 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
from paddle import nn
import fasttext
class AsterLoss(nn.Layer):
def __init__(self,
weight=None,
size_average=True,
ignore_index=-100,
sequence_normalize=False,
sample_normalize=True,
**kwargs):
super(AsterLoss, self).__init__()
self.weight = weight
self.size_average = size_average
self.ignore_index = ignore_index
self.sequence_normalize = sequence_normalize
self.sample_normalize = sample_normalize
self.loss_func = paddle.nn.CosineSimilarity()
def forward(self, predicts, batch):
targets = batch[1].astype("int64")
label_lengths = batch[2].astype('int64')
# sem_target = batch[3].astype('float32')
embedding_vectors = predicts['embedding_vectors']
rec_pred = predicts['rec_pred']
# semantic loss
# print(embedding_vectors)
# print(embedding_vectors.shape)
# targets = fasttext[targets]
# sem_loss = 1 - self.loss_func(embedding_vectors, targets)
# rec loss
batch_size, num_steps, num_classes = rec_pred.shape[0], rec_pred.shape[
1], rec_pred.shape[2]
assert len(targets.shape) == len(list(rec_pred.shape)) - 1, \
"The target's shape and inputs's shape is [N, d] and [N, num_steps]"
mask = paddle.zeros([batch_size, num_steps])
for i in range(batch_size):
mask[i, :label_lengths[i]] = 1
mask = paddle.cast(mask, "float32")
max_length = max(label_lengths)
assert max_length == rec_pred.shape[1]
targets = targets[:, :max_length]
mask = mask[:, :max_length]
rec_pred = paddle.reshape(rec_pred, [-1, rec_pred.shape[-1]])
input = nn.functional.log_softmax(rec_pred, axis=1)
targets = paddle.reshape(targets, [-1, 1])
mask = paddle.reshape(mask, [-1, 1])
# print("input:", input)
output = -paddle.gather(input, index=targets, axis=1) * mask
output = paddle.sum(output)
if self.sequence_normalize:
output = output / paddle.sum(mask)
if self.sample_normalize:
output = output / batch_size
loss = output
return {'loss': loss} # , 'sem_loss':sem_loss}