File size: 6,678 Bytes
8713ab2
 
 
 
 
 
 
 
 
 
 
 
 
 
dc41f2f
8713ab2
dc41f2f
8713ab2
dc41f2f
8713ab2
dc41f2f
8713ab2
dc41f2f
8713ab2
dc41f2f
8713ab2
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
dc41f2f
8713ab2
 
 
 
 
 
 
 
 
 
 
 
 
 
 
dc41f2f
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
import pandas as pd
import torch
from torch.utils.data import Dataset
from PIL import Image
import argparse
from evaluate import load
from transformers import TrOCRProcessor, VisionEncoderDecoderModel, Seq2SeqTrainer, Seq2SeqTrainingArguments, default_data_collator, AdamW
import torchvision.transforms as transforms
from augments import RandAug, RandRotate

parser = argparse.ArgumentParser('arguments for the code')

parser.add_argument('--root_path', type=str, default="",
                    help='Root path to data files.')
parser.add_argument('--tr_data_path', type=str, default="/path/to/train_data.csv",
                    help='Path to .csv file containing the training data.')
parser.add_argument('--val_data_path', type=str, default="/path/to/val_data.csv",
                    help='Path to .csv file containing the validation data.')
parser.add_argument('--output_path', type=str, default="./output/path/",
                    help='Path for saving training results.')
parser.add_argument('--model_path', type=str, default="/model/path/",
                    help='Path to trocr model')
parser.add_argument('--processor_path', type=str, default="/processor/path/",
                    help='Path to trocr processor')
parser.add_argument('--epochs', type=int, default=15,
                    help='Training epochs.')
parser.add_argument('--batch_size', type=int, default=16,
                    help='Training epochs.')
parser.add_argument('--device', type=str, default="cuda:0",
                    help='Device used for training.')
parser.add_argument('--augment', type=int, default=0,
                    help='Defines if image augmentations are used during training.')

args = parser.parse_args()

# Initialize processor and model
processor = TrOCRProcessor.from_pretrained(args.processor_path)
model = VisionEncoderDecoderModel.from_pretrained(args.model_path)
model.to(args.device)

# Initialize metrics
cer_metric = load("cer")
wer_metric = load("wer")

# Load train and validation data to dataframes
train_df = pd.read_csv(args.tr_data_path)
val_df = pd.read_csv(args.val_data_path)

# Reset the indices to start from zero
train_df.reset_index(drop=True, inplace=True)
val_df.reset_index(drop=True, inplace=True)

# Torch dataset
class TextlineDataset(Dataset):
    def __init__(self, root_dir, df, processor, max_target_length=128, augment=False):
        self.root_dir = root_dir
        self.df = df
        self.processor = processor
        self.max_target_length = max_target_length
        self.augment = augment
        self.augmentator = RandAug()
        self.rotator = RandRotate()

    def __len__(self):
        return len(self.df)

    def __getitem__(self, idx):
        # get file name + text 
        file_name = self.df['file_name'][idx]
        text = self.df['text'][idx]

        # prepare image (i.e. resize + normalize)
        image = Image.open(self.root_dir + file_name).convert("RGB")

        if self.augment:
            image = self.augmentator(image)

        pixel_values = self.processor(image, return_tensors="pt").pixel_values
        
        # add labels (input_ids) by encoding the text
        labels = self.processor.tokenizer(text, 
                                          padding="max_length", truncation=True, 
                                          max_length=self.max_target_length).input_ids
        # important: make sure that PAD tokens are ignored by the loss function
        labels = [label if label != self.processor.tokenizer.pad_token_id else -100 for label in labels]
        #encoding = {"pixel_values": pixel_values.squeeze(0),"labels":labels} 
        encoding = {"pixel_values": pixel_values.squeeze(), "labels": torch.tensor(labels)}
        return encoding

# Create train and validation datasets
train_dataset = TextlineDataset(root_dir=args.root_path,
                           df=train_df,
                           processor=processor,
                           augment=args.augment)

eval_dataset = TextlineDataset(root_dir=args.root_path,
                           df=val_df,
                           processor=processor,
                           augment=False)

print("Number of training examples:", len(train_dataset))
print("Number of validation examples:", len(eval_dataset))

# Define model configuration

# set special tokens used for creating the decoder_input_ids from the labels
model.config.decoder_start_token_id = processor.tokenizer.cls_token_id
model.config.pad_token_id = processor.tokenizer.pad_token_id
# make sure vocab size is set correctly
model.config.vocab_size = model.config.decoder.vocab_size
# set beam search parameters
model.config.eos_token_id = processor.tokenizer.sep_token_id
model.config.max_length = 64
model.config.early_stopping = True
model.config.no_repeat_ngram_size = 3
model.config.length_penalty = 2.0
model.config.num_beams = 1

# Set arguments for model training
# For all argumenst see https://huggingface.co/docs/transformers/main_classes/trainer#transformers.Seq2SeqTrainingArguments
training_args = Seq2SeqTrainingArguments(
    predict_with_generate=True,
    eval_strategy="epoch",
    save_strategy="epoch",
    logging_strategy="steps",
    logging_steps=50,
    per_device_train_batch_size=args.batch_size,
    per_device_eval_batch_size=args.batch_size,
    load_best_model_at_end=True,
    metric_for_best_model='cer',
    greater_is_better=False,
    fp16=True, 
    num_train_epochs=args.epochs,
    save_total_limit=1,
    output_dir=args.output_path,
    optim='adamw_torch'
)

# Function for computing CER and WER metrics for the prediction results
def compute_metrics(pred):
    labels_ids = pred.label_ids
    pred_ids = pred.predictions

    pred_str = processor.batch_decode(pred_ids, skip_special_tokens=True)
    labels_ids[labels_ids == -100] = processor.tokenizer.pad_token_id
    label_str = processor.batch_decode(labels_ids, skip_special_tokens=True)

    cer = cer_metric.compute(predictions=pred_str, references=label_str)
    wer = wer_metric.compute(predictions=pred_str, references=label_str)

    return {"cer": cer, "wer": wer}


# Instantiate trainer
# For all parameters see: https://huggingface.co/docs/transformers/main_classes/trainer#transformers.Seq2SeqTrainer
trainer = Seq2SeqTrainer(
    model=model,
    tokenizer=processor.image_processor,
    args=training_args,
    compute_metrics=compute_metrics,
    train_dataset=train_dataset,
    eval_dataset=eval_dataset,
    data_collator=default_data_collator,
)

# Train the model
trainer.train()
#trainer.train(resume_from_checkpoint = True)
model.save_pretrained(args.output_path)
processor.save_pretrained(args.output_path + "/processor")