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Diffstat (limited to 'src/text_recognizer/networks/vq_transformer.py')
-rw-r--r-- | src/text_recognizer/networks/vq_transformer.py | 150 |
1 files changed, 0 insertions, 150 deletions
diff --git a/src/text_recognizer/networks/vq_transformer.py b/src/text_recognizer/networks/vq_transformer.py deleted file mode 100644 index c673d96..0000000 --- a/src/text_recognizer/networks/vq_transformer.py +++ /dev/null @@ -1,150 +0,0 @@ -"""A VQ-Transformer for image to text recognition.""" -from typing import Dict, Optional, Tuple - -from einops import rearrange, repeat -import torch -from torch import nn -from torch import Tensor - -from text_recognizer.networks.transformer import PositionalEncoding, Transformer -from text_recognizer.networks.util import activation_function -from text_recognizer.networks.util import configure_backbone -from text_recognizer.networks.vqvae.encoder import _ResidualBlock - - -class VQTransformer(nn.Module): - """VQ+Transfomer for image to character sequence prediction.""" - - def __init__( - self, - num_encoder_layers: int, - num_decoder_layers: int, - hidden_dim: int, - vocab_size: int, - num_heads: int, - adaptive_pool_dim: Tuple, - expansion_dim: int, - dropout_rate: float, - trg_pad_index: int, - max_len: int, - backbone: str, - backbone_args: Optional[Dict] = None, - activation: str = "gelu", - ) -> None: - super().__init__() - - # Configure vector quantized backbone. - self.backbone = configure_backbone(backbone, backbone_args) - self.conv = nn.Sequential( - nn.Conv2d(hidden_dim, hidden_dim, kernel_size=3, stride=2), - nn.ReLU(inplace=True), - ) - - # Configure embeddings for Transformer network. - self.trg_pad_index = trg_pad_index - self.vocab_size = vocab_size - self.character_embedding = nn.Embedding(self.vocab_size, hidden_dim) - self.src_position_embedding = nn.Parameter(torch.randn(1, max_len, hidden_dim)) - self.trg_position_encoding = PositionalEncoding(hidden_dim, dropout_rate) - nn.init.normal_(self.character_embedding.weight, std=0.02) - - self.adaptive_pool = ( - nn.AdaptiveAvgPool2d((adaptive_pool_dim)) if adaptive_pool_dim else None - ) - - self.transformer = Transformer( - num_encoder_layers, - num_decoder_layers, - hidden_dim, - num_heads, - expansion_dim, - dropout_rate, - activation, - ) - - self.head = nn.Sequential(nn.Linear(hidden_dim, vocab_size),) - - def _create_trg_mask(self, trg: Tensor) -> Tensor: - # Move this outside the transformer. - trg_pad_mask = (trg != self.trg_pad_index)[:, None, None] - trg_len = trg.shape[1] - trg_sub_mask = torch.tril( - torch.ones((trg_len, trg_len), device=trg.device) - ).bool() - trg_mask = trg_pad_mask & trg_sub_mask - return trg_mask - - def encoder(self, src: Tensor) -> Tensor: - """Forward pass with the encoder of the transformer.""" - return self.transformer.encoder(src) - - def decoder(self, trg: Tensor, memory: Tensor, trg_mask: Tensor) -> Tensor: - """Forward pass with the decoder of the transformer + classification head.""" - return self.head( - self.transformer.decoder(trg=trg, memory=memory, trg_mask=trg_mask) - ) - - def extract_image_features(self, src: Tensor) -> Tuple[Tensor, Tensor]: - """Extracts image features with a backbone neural network. - - It seem like the winning idea was to swap channels and width dimension and collapse - the height dimension. The transformer is learning like a baby with this implementation!!! :D - Ohhhh, the joy I am experiencing right now!! Bring in the beers! :D :D :D - - Args: - src (Tensor): Input tensor. - - Returns: - Tensor: The input src to the transformer and the vq loss. - - """ - # If batch dimension is missing, it needs to be added. - if len(src.shape) < 4: - src = src[(None,) * (4 - len(src.shape))] - src, vq_loss = self.backbone.encode(src) - # src = self.backbone.decoder.res_block(src) - src = self.conv(src) - - if self.adaptive_pool is not None: - src = rearrange(src, "b c h w -> b w c h") - src = self.adaptive_pool(src) - src = src.squeeze(3) - else: - src = rearrange(src, "b c h w -> b (w h) c") - - b, t, _ = src.shape - - src += self.src_position_embedding[:, :t] - - return src, vq_loss - - def target_embedding(self, trg: Tensor) -> Tensor: - """Encodes target tensor with embedding and postion. - - Args: - trg (Tensor): Target tensor. - - Returns: - Tensor: Encoded target tensor. - - """ - trg = self.character_embedding(trg.long()) - trg = self.trg_position_encoding(trg) - return trg - - def decode_image_features( - self, image_features: Tensor, trg: Optional[Tensor] = None - ) -> Tensor: - """Takes images features from the backbone and decodes them with the transformer.""" - trg_mask = self._create_trg_mask(trg) - trg = self.target_embedding(trg) - out = self.transformer(image_features, trg, trg_mask=trg_mask) - - logits = self.head(out) - return logits - - def forward(self, x: Tensor, trg: Optional[Tensor] = None) -> Tensor: - """Forward pass with CNN transfomer.""" - image_features, vq_loss = self.extract_image_features(x) - logits = self.decode_image_features(image_features, trg) - return logits, vq_loss |