ABINet-OCR / modules /model_vision.py
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import logging
import torch.nn as nn
from fastai.vision import *
from modules.attention import *
from modules.backbone import ResTranformer
from modules.model import Model
from modules.resnet import resnet45
class BaseVision(Model):
def __init__(self, config):
super().__init__(config)
self.loss_weight = ifnone(config.model_vision_loss_weight, 1.0)
self.out_channels = ifnone(config.model_vision_d_model, 512)
if config.model_vision_backbone == 'transformer':
self.backbone = ResTranformer(config)
else: self.backbone = resnet45()
if config.model_vision_attention == 'position':
mode = ifnone(config.model_vision_attention_mode, 'nearest')
self.attention = PositionAttention(
max_length=config.dataset_max_length + 1, # additional stop token
mode=mode,
)
elif config.model_vision_attention == 'attention':
self.attention = Attention(
max_length=config.dataset_max_length + 1, # additional stop token
n_feature=8*32,
)
else:
raise Exception(f'{config.model_vision_attention} is not valid.')
self.cls = nn.Linear(self.out_channels, self.charset.num_classes)
if config.model_vision_checkpoint is not None:
logging.info(f'Read vision model from {config.model_vision_checkpoint}.')
self.load(config.model_vision_checkpoint)
def forward(self, images, *args):
features = self.backbone(images) # (N, E, H, W)
attn_vecs, attn_scores = self.attention(features) # (N, T, E), (N, T, H, W)
logits = self.cls(attn_vecs) # (N, T, C)
pt_lengths = self._get_length(logits)
return {'feature': attn_vecs, 'logits': logits, 'pt_lengths': pt_lengths,
'attn_scores': attn_scores, 'loss_weight':self.loss_weight, 'name': 'vision'}